The mess:
Some parts use alsoPropagate for late propagation, others using an immediate one (propagate()),
causing edge cases, ugly/hacky code, and the tendency for bugs
The basic idea is that all commands are propagated via alsoPropagate (i.e. added to a list) and the
top-most call() is responsible for going over that list and actually propagating them (and wrapping
them in MULTI/EXEC if there's more than one command). This is done in the new function,
propagatePendingCommands.
Callers to propagatePendingCommands:
1. top-most call() (we want all nested call()s to add to the also_propagate array and just the top-most
one to propagate them) - via `afterCommand`
2. handleClientsBlockedOnKeys: it is out of call() context and it may propagate stuff - via `afterCommand`.
3. handleClientsBlockedOnKeys edge case: if the looked-up key is already expired, we will propagate the
expire but will not unblock any client so `afterCommand` isn't called. in that case, we have to propagate
the deletion explicitly.
4. cron stuff: active-expire and eviction may also propagate stuff
5. modules: the module API allows to propagate stuff from just about anywhere (timers, keyspace notifications,
threads). I could have tried to catch all the out-of-call-context places but it seemed easier to handle it in one
place: when we free the context. in the spirit of what was done in call(), only the top-most freeing of a module
context may cause propagation.
6. modules: when using a thread-safe ctx it's not clear when/if the ctx will be freed. we do know that the module
must lock the GIL before calling RM_Replicate/RM_Call so we propagate the pending commands when
releasing the GIL.
A "known limitation", which were actually a bug, was fixed because of this commit (see propagate.tcl):
When using a mix of RM_Call with `!` and RM_Replicate, the command would propagate out-of-order:
first all the commands from RM_Call, and then the ones from RM_Replicate
Another thing worth mentioning is that if, in the past, a client would issue a MULTI/EXEC with just one
write command the server would blindly propagate the MULTI/EXEC too, even though it's redundant.
not anymore.
This commit renames propagate() to propagateNow() in order to cause conflicts in pending PRs.
propagatePendingCommands is the only caller of propagateNow, which is now a static, internal helper function.
Optimizations:
1. alsoPropagate will not add stuff to also_propagate if there's no AOF and replicas
2. alsoPropagate reallocs also_propagagte exponentially, to save calls to memmove
Bugfixes:
1. CONFIG SET can create evictions, sending notifications which can cause to dirty++ with modules.
we need to prevent it from propagating to AOF/replicas
2. We need to set current_client in RM_Call. buggy scenario:
- CONFIG SET maxmemory, eviction notifications, module hook calls RM_Call
- assertion in lookupKey crashes, because current_client has CONFIG SET, which isn't CMD_WRITE
3. minor: in eviction, call propagateDeletion after notification, like active-expire and all commands
(we always send a notification before propagating the command)
## background
Till now CONFIG SET was blocked during loading.
(In the not so distant past, GET was disallowed too)
We recently (not released yet) added an async-loading mode, see #9323,
and during that time it'll serve CONFIG SET and any other command.
And now we realized (#9770) that some configs, and commands are dangerous
during async-loading.
## changes
* Allow most CONFIG SET during loading (both on async-loading and normal loading)
* Allow CONFIG REWRITE and CONFIG RESETSTAT during loading
* Block a few config during loading (`appendonly`, `repl-diskless-load`, and `dir`)
* Block a few commands during loading (list below)
## the blocked commands:
* SAVE - obviously we don't wanna start a foregreound save during loading 8-)
* BGSAVE - we don't mind to schedule one, but we don't wanna fork now
* BGREWRITEAOF - we don't mind to schedule one, but we don't wanna fork now
* MODULE - we obviously don't wanna unload a module during replication / rdb loading
(MODULE HELP and MODULE LIST are not blocked)
* SYNC / PSYNC - we're in the middle of RDB loading from master, must not allow sync
requests now.
* REPLICAOF / SLAVEOF - we're in the middle of replicating, maybe it makes sense to let
the user abort it, but he couldn't do that so far, i don't wanna take any risk of bugs due to odd state.
* CLUSTER - only allow [HELP, SLOTS, NODES, INFO, MYID, LINKS, KEYSLOT, COUNTKEYSINSLOT,
GETKEYSINSLOT, RESET, REPLICAS, COUNT_FAILURE_REPORTS], for others, preserve the status quo
## other fixes
* processEventsWhileBlocked had an issue when being nested, this could happen with a busy script
during async loading (new), but also in a busy script during AOF loading (old). this lead to a crash in
the scenario described in #6988
# Background
The main goal of this PR is to remove relevant logics on Lua script verbatim replication,
only keeping effects replication logic, which has been set as default since Redis 5.0.
As a result, Lua in Redis 7.0 would be acting the same as Redis 6.0 with default
configuration from users' point of view.
There are lots of reasons to remove verbatim replication.
Antirez has listed some of the benefits in Issue #5292:
>1. No longer need to explain to users side effects into scripts.
They can do whatever they want.
>2. No need for a cache about scripts that we sent or not to the slaves.
>3. No need to sort the output of certain commands inside scripts
(SMEMBERS and others): this both simplifies and gains speed.
>4. No need to store scripts inside the RDB file in order to startup correctly.
>5. No problems about evicting keys during the script execution.
When looking back at Redis 5.0, antirez and core team decided to set the config
`lua-replicate-commands yes` by default instead of removing verbatim replication
directly, in case some bad situations happened. 3 years later now before Redis 7.0,
it's time to remove it formally.
# Changes
- configuration for lua-replicate-commands removed
- created config file stub for backward compatibility
- Replication script cache removed
- this is useless under script effects replication
- relevant statistics also removed
- script persistence in RDB files is also removed
- Propagation of SCRIPT LOAD and SCRIPT FLUSH to replica / AOF removed
- Deterministic execution logic in scripts removed (i.e. don't run write commands
after random ones, and sorting output of commands with random order)
- the flags indicating which commands have non-deterministic results are kept as hints to clients.
- `redis.replicate_commands()` & `redis.set_repl()` changed
- now `redis.replicate_commands()` does nothing and return an 1
- ...and then `redis.set_repl()` can be issued before `redis.replicate_commands()` now
- Relevant TCL cases adjusted
- DEBUG lua-always-replicate-commands removed
# Other changes
- Fix a recent bug comparing CLIENT_ID_AOF to original_client->flags instead of id. (introduced in #9780)
Co-authored-by: Oran Agra <oran@redislabs.com>
Recent PRs have introduced some failures, this commit
try to fix these CI failures. Here are the changes:
1. Enable debug-command in sentinel test.
```
Master reboot in very short time: ERR DEBUG command not allowed. If the
enable-debug-command option is set to "local", you can run it from a
local connection, otherwise you need to set this option in the
configuration file, and then restart the server.
```
2. Enable protected-config in sentinel test.
```
SDOWN is triggered by misconfigured instance replying with errors: ERR
CONFIG SET failed (possibly related to argument 'dir') - can't set
protected config
```
3. Enable debug-command in cluster test.
```
Verify slaves consistency: ERR DEBUG command not allowed. If the
enable-debug-command option is set to "local", you can run it from a
local connection, otherwise you need to set this option in the
configuration file, and then restart the server.
```
4. quicklist fill should be signed int.
The reason for the modification is to eliminate the warning.
Modify `int fill: QL_FILL_BITS` to `signed int fill: QL_FILL_BITS`
The first three were introduced at #9920 (same issue).
And the last one was introduced at #9962.
Block sensitive configs and commands by default.
* `enable-protected-configs` - block modification of configs with the new `PROTECTED_CONFIG` flag.
Currently we add this flag to `dbfilename`, and `dir` configs,
all of which are non-mutable configs that can set a file redis will write to.
* `enable-debug-command` - block the `DEBUG` command
* `enable-module-command` - block the `MODULE` command
These have a default value set to `no`, so that these features are not
exposed by default to client connections, and can only be set by modifying the config file.
Users can change each of these to either `yes` (allow all access), or `local` (allow access from
local TCP connections and unix domain connections)
Note that this is a **breaking change** (specifically the part about MODULE command being disabled by default).
I.e. we don't consider DEBUG command being blocked as an issue (people shouldn't have been using it),
and the few configs we protected are unlikely to have been set at runtime anyway.
On the other hand, it's likely to assume some users who use modules, load them from the config file anyway.
Note that's the whole point of this PR, for redis to be more secure by default and reduce the attack surface on
innocent users, so secure defaults will necessarily mean a breaking change.
some languages can build a json-like object by parsing a textual json,
but it works poorly when attributes contain hyphens
example in JS:
```
let j = JSON.parse(json)
j['key-name'] <- works
j.key-name <= illegal syntax
```
Introduce memory management on cluster link buffers:
* Introduce a new `cluster-link-sendbuf-limit` config that caps memory usage of cluster bus link send buffers.
* Introduce a new `CLUSTER LINKS` command that displays current TCP links to/from peers.
* Introduce a new `mem_cluster_links` field under `INFO` command output, which displays the overall memory usage by all current cluster links.
* Introduce a new `total_cluster_links_buffer_limit_exceeded` field under `CLUSTER INFO` command output, which displays the accumulated count of cluster links freed due to `cluster-link-sendbuf-limit`.
Delete the hardcoded command table and replace it with an auto-generated table, based
on a JSON file that describes the commands (each command must have a JSON file).
These JSON files are the SSOT of everything there is to know about Redis commands,
and it is reflected fully in COMMAND INFO.
These JSON files are used to generate commands.c (using a python script), which is then
committed to the repo and compiled.
The purpose is:
* Clients and proxies will be able to get much more info from redis, instead of relying on hard coded logic.
* drop the dependency between Redis-user and the commands.json in redis-doc.
* delete help.h and have redis-cli learn everything it needs to know just by issuing COMMAND (will be
done in a separate PR)
* redis.io should stop using commands.json and learn everything from Redis (ultimately one of the release
artifacts should be a large JSON, containing all the information about all of the commands, which will be
generated from COMMAND's reply)
* the byproduct of this is:
* module commands will be able to provide that info and possibly be more of a first-class citizens
* in theory, one may be able to generate a redis client library for a strictly typed language, by using this info.
### Interface changes
#### COMMAND INFO's reply change (and arg-less COMMAND)
Before this commit the reply at index 7 contained the key-specs list
and reply at index 8 contained the sub-commands list (Both unreleased).
Now, reply at index 7 is a map of:
- summary - short command description
- since - debut version
- group - command group
- complexity - complexity string
- doc-flags - flags used for documentation (e.g. "deprecated")
- deprecated-since - if deprecated, from which version?
- replaced-by - if deprecated, which command replaced it?
- history - a list of (version, what-changed) tuples
- hints - a list of strings, meant to provide hints for clients/proxies. see https://github.com/redis/redis/issues/9876
- arguments - an array of arguments. each element is a map, with the possibility of nesting (sub-arguments)
- key-specs - an array of keys specs (already in unstable, just changed location)
- subcommands - a list of sub-commands (already in unstable, just changed location)
- reply-schema - will be added in the future (see https://github.com/redis/redis/issues/9845)
more details on these can be found in https://github.com/redis/redis-doc/pull/1697
only the first three fields are mandatory
#### API changes (unreleased API obviously)
now they take RedisModuleCommand opaque pointer instead of looking up the command by name
- RM_CreateSubcommand
- RM_AddCommandKeySpec
- RM_SetCommandKeySpecBeginSearchIndex
- RM_SetCommandKeySpecBeginSearchKeyword
- RM_SetCommandKeySpecFindKeysRange
- RM_SetCommandKeySpecFindKeysKeynum
Currently, we did not add module API to provide additional information about their commands because
we couldn't agree on how the API should look like, see https://github.com/redis/redis/issues/9944.
### Somehow related changes
1. Literals should be in uppercase while placeholder in lowercase. Now all the GEO* command
will be documented with M|KM|FT|MI and can take both lowercase and uppercase
### Unrelated changes
1. Bugfix: no_madaory_keys was absent in COMMAND's reply
2. expose CMD_MODULE as "module" via COMMAND
3. have a dedicated uint64 for ACL categories (instead of having them in the same uint64 as command flags)
Co-authored-by: Itamar Haber <itamar@garantiadata.com>
For `SENTINEL SET`, we can use in these ways:
1. SENTINEL SET mymaster quorum 3
2. SENTINEL SET mymaster quorum 5 parallel-syncs 1
For `SENTINEL SIMULATE-FAILURE`, although it is only used for testing:
1. SENTINEL SIMULATE-FAILURE CRASH-AFTER-ELECTION
2. SENTINEL SIMULATE-FAILURE CRASH-AFTER-ELECTION CRASH-AFTER-PROMOTION
When disabling redis oom-score-adj managment we restore the
base value read before enabling oom-score-adj management.
This fixes an issue introduced in #9748 where updating
`oom-score-adj-values` while `oom-score-adj` was set to `no`
would write the base oom score adj value read on startup to `/proc`.
This is a bug since while `oom-score-adj` is disabled we should
never write to proc and let external processes manage it.
Added appropriate tests.
Redis function unit is located inside functions.c
and contains Redis Function implementation:
1. FUNCTION commands:
* FUNCTION CREATE
* FCALL
* FCALL_RO
* FUNCTION DELETE
* FUNCTION KILL
* FUNCTION INFO
2. Register engine
In addition, this commit introduce the first engine
that uses the Redis Function capabilities, the
Lua engine.
Script unit is a new unit located on script.c.
Its purpose is to provides an API for functions (and eval)
to interact with Redis. Interaction includes mostly
executing commands, but also functionalities like calling
Redis back on long scripts or check if the script was killed.
The interaction is done using a scriptRunCtx object that
need to be created by the user and initialized using scriptPrepareForRun.
Detailed list of functionalities expose by the unit:
1. Calling commands (including all the validation checks such as
acl, cluster, read only run, ...)
2. Set Resp
3. Set Replication method (AOF/REPLICATION/NONE)
4. Call Redis back to on long running scripts to allow Redis reply
to clients and perform script kill
The commit introduce the new unit and uses it on eval commands to
interact with Redis.
The following variable was renamed:
1. lua_caller -> script_caller
2. lua_time_limit -> script_time_limit
3. lua_timedout -> script_timedout
4. lua_oom -> script_oom
5. lua_disable_deny_script -> script_disable_deny_script
6. in_eval -> in_script
The following variables was moved to lctx under eval.c
1. lua
2. lua_client
3. lua_cur_script
4. lua_scripts
5. lua_scripts_mem
6. lua_replicate_commands
7. lua_write_dirty
8. lua_random_dirty
9. lua_multi_emitted
10. lua_repl
11. lua_kill
12. lua_time_start
13. lua_time_snapshot
This commit is in a low risk of introducing any issues and it
is just moving varibales around and not changing any logic.
We can now do: `config set maxmemory 10m repl-backlog-size 5m`
## Basic algorithm to support "transaction like" config sets:
1. Backup all relevant current values (via get).
2. Run "verify" and "set" on everything, if we fail run "restore".
3. Run "apply" on everything (optional optimization: skip functions already run). If we fail run "restore".
4. Return success.
### restore
1. Run set on everything in backup. If we fail log it and continue (this puts us in an undefined
state but we decided it's better than the alternative of panicking). This indicates either a bug
or some unsupported external state.
2. Run apply on everything in backup (optimization: skip functions already run). If we fail log
it (see comment above).
3. Return error.
## Implementation/design changes:
* Apply function are idempotent (have no effect if they are run more than once for the same config).
* No indication in set functions if we're reading the config or running from the `CONFIG SET` command
(removed `update` argument).
* Set function should set some config variable and assume an (optional) apply function will use that
later to apply. If we know this setting can be safely applied immediately and can always be reverted
and doesn't depend on any other configuration we can apply immediately from within the set function
(and not store the setting anywhere). This is the case of this `dir` config, for example, which has no
apply function. No apply function is need also in the case that setting the variable in the `server` struct
is all that needs to be done to make the configuration take effect. Note that the original concept of `update_fn`,
which received the old and new values was removed and replaced by the optional apply function.
* Apply functions use settings written to the `server` struct and don't receive any inputs.
* I take care that for the generic (non-special) configs if there's no change I avoid calling the setter (possible
optimization: avoid calling the apply function as well).
* Passing the same config parameter more than once to `config set` will fail. You can't do `config set my-setting
value1 my-setting value2`.
Note that getting `save` in the context of the conf file parsing to work here as before was a pain.
The conf file supports an aggregate `save` definition, where each `save` line is added to the server's
save params. This is unlike any other line in the config file where each line overwrites any previous
configuration. Since we now support passing multiple save params in a single line (see top comments
about `save` in https://github.com/redis/redis/pull/9644) we should deprecate the aggregate nature of
this config line and perhaps reduce this ugly code in the future.
Remove lcsGetKeys to clean up the remaining STRALGO after #9733.
i.e. it still used a getkeys_proc which was still looking for the KEYS or STRINGS arguments
Part three of implementing #8702, following #8887 and #9366 .
## Description of the feature
1. Replace the ziplist container of quicklist with listpack.
2. Convert existing quicklist ziplists on RDB loading time. an O(n) operation.
## Interface changes
1. New `list-max-listpack-size` config is an alias for `list-max-ziplist-size`.
2. Replace `debug ziplist` command with `debug listpack`.
## Internal changes
1. Add `lpMerge` to merge two listpacks . (same as `ziplistMerge`)
2. Add `lpRepr` to print info of listpack which is used in debugCommand and `quicklistRepr`. (same as `ziplistRepr`)
3. Replace `QUICKLIST_NODE_CONTAINER_ZIPLIST` with `QUICKLIST_NODE_CONTAINER_PACKED`(following #9357 ).
It represent that a quicklistNode is a packed node, as opposed to a plain node.
4. Remove `createZiplistObject` method, which is never used.
5. Calculate listpack entry size using overhead overestimation in `quicklistAllowInsert`.
We prefer an overestimation, which would at worse lead to a few bytes below the lowest limit of 4k.
## Improvements
1. Calling `lpShrinkToFit` after converting Ziplist to listpack, which was missed at #9366.
2. Optimize `quicklistAppendPlainNode` to avoid memcpy data.
## Bugfix
1. Fix crash in `quicklistRepr` when ziplist is compressed, introduced from #9366.
## Test
1. Add unittest for `lpMerge`.
2. Modify the old quicklist ziplist corrupt dump test.
Co-authored-by: Oran Agra <oran@redislabs.com>
Some people complain that QUIT is missing from help/command table.
Not appearing in COMMAND command, command stats, ACL, etc.
and instead, there's a hack in processCommand with a comment that looks outdated.
Note that it is [documented](https://redis.io/commands/quit)
At the same time, HOST: and POST are there in the command table although these are not real commands.
They would appear in the COMMAND command, and even in commandstats.
Other changes:
1. Initialize the static logged_time static var in securityWarningCommand
2. add `no-auth` flag to RESET so it can always be executed.
Currently PING returns different status when server is not serving data,
for example when `LOADING` or `BUSY`.
But same was not true for `MASTERDOWN`
This commit makes PING reply with `MASTERDOWN` when
replica-serve-stale-data=no and link is MASTER is down.
Drop the STRALGO command, now LCS is a command of its own and it only works on keys (not input strings).
The motivation is that STRALGO's syntax was really messed-up...
- assumes all (future) string algorithms will take similar arguments
- mixes command that takes keys and one that doesn't in the same command.
- make it nearly impossible to expose the right key spec in COMMAND INFO (issues cluster clients)
- hard for cluster clients to determine the key names (firstkey, lastkey, etc)
- hard for ACL / flags (is it a read command?)
This is a breaking change.
The client flags is a 64 bit integer, but the temporary cached value on the stack of call() is 32 bit.
luckily this doesn't lead to any bugs since the only flags used against this variables are below 32 bit.
This refactors all `CONFIG SET`s and conf file loading arguments go through
the generic config handling interface.
Refactoring changes:
- All config params go through the `standardConfig` interface (some stuff which
is only related to the config file and not the `CONFIG` command still has special
handling for rewrite/config file parsing, `loadmodule`, for example.) .
- Added `MULTI_ARG_CONFIG` flag for configs to signify they receive a variable
number of arguments instead of a single argument. This is used to break up space
separated arguments to `CONFIG SET` so the generic setter interface can pass
multiple arguments to the setter function. When parsing the config file we also break
up anything after the config name into multiple arguments to the setter function.
Interface changes:
- A side effect of the above interface is that the `bind` argument in the config file can
be empty (no argument at all) this is treated the same as passing an single empty
string argument (same as `save` already used to work).
- Support rewrite and setting `watchdog-period` from config file (was only supported
by the CONFIG command till now).
- Another side effect is that the `save T X` config argument now supports multiple
Time-Changes pairs in a single line like its `CONFIG SET` counterpart. So in the
config file you can either do:
```
save 3600 1
save 600 10
```
or do
```
save 3600 1 600 10
```
Co-authored-by: Bjorn Svensson <bjorn.a.svensson@est.tech>
For diskless replication in swapdb mode, considering we already spend replica memory
having a backup of current db to restore in case of failure, we can have the following benefits
by instead swapping database only in case we succeeded in transferring db from master:
- Avoid `LOADING` response during failed and successful synchronization for cases where the
replica is already up and running with data.
- Faster total time of diskless replication, because now we're moving from Transfer + Flush + Load
time to Transfer + Load only. Flushing the tempDb is done asynchronously after swapping.
- This could be implemented also for disk replication with similar benefits if consumers are willing
to spend the extra memory usage.
General notes:
- The concept of `backupDb` becomes `tempDb` for clarity.
- Async loading mode will only kick in if the replica is syncing from a master that has the same
repl-id the one it had before. i.e. the data it's getting belongs to a different time of the same timeline.
- New property in INFO: `async_loading` to differentiate from the blocking loading
- Slot to Key mapping is now a field of `redisDb` as it's more natural to access it from both server.db
and the tempDb that is passed around.
- Because this is affecting replicas only, we assume that if they are not readonly and write commands
during replication, they are lost after SYNC same way as before, but we're still denying CONFIG SET
here anyways to avoid complications.
Considerations for review:
- We have many cases where server.loading flag is used and even though I tried my best, there may
be cases where async_loading should be checked as well and cases where it shouldn't (would require
very good understanding of whole code)
- Several places that had different behavior depending on the loading flag where actually meant to just
handle commands coming from the AOF client differently than ones coming from real clients, changed
to check CLIENT_ID_AOF instead.
**Additional for Release Notes**
- Bugfix - server.dirty was not incremented for any kind of diskless replication, as effect it wouldn't
contribute on triggering next database SAVE
- New flag for RM_GetContextFlags module API: REDISMODULE_CTX_FLAGS_ASYNC_LOADING
- Deprecated RedisModuleEvent_ReplBackup. Starting from Redis 7.0, we don't fire this event.
Instead, we have the new RedisModuleEvent_ReplAsyncLoad holding 3 sub-events: STARTED,
ABORTED and COMPLETED.
- New module flag REDISMODULE_OPTIONS_HANDLE_REPL_ASYNC_LOAD for RedisModule_SetModuleOptions
to allow modules to declare they support the diskless replication with async loading (when absent, we fall
back to disk-based loading).
Co-authored-by: Eduardo Semprebon <edus@saxobank.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
Add new no-mandatory-keys flag to support COMMAND GETKEYS of commands
which have no mandatory keys.
In the past we would have got this error:
```
127.0.0.1:6379> command getkeys eval "return 1" 0
(error) ERR Invalid arguments specified for command
```
After PR #9166 , replication backlog is not a real block of memory, just contains a
reference points to replication buffer's block and the blocks index (to accelerate
search offset when partial sync), so we need update both replication buffer's block's
offset and replication backlog blocks index's offset when master restart from RDB,
since the `server.master_repl_offset` is changed.
The implications of this bug was just a slow search, but not a replication failure.
Add timestamp annotation in AOF, one part of #9325.
Enabled with the new `aof-timestamp-enabled` config option.
Timestamp annotation format is "#TS:${timestamp}\r\n"."
TS" is short of timestamp and this method could save extra bytes in AOF.
We can use timestamp annotation for some special functions.
- know the executing time of commands
- restore data to a specific point-in-time (by using redis-check-rdb to truncate the file)
## Background
For redis master, one replica uses one copy of replication buffer, that is a big waste of memory,
more replicas more waste, and allocate/free memory for every reply list also cost much.
If we set client-output-buffer-limit small and write traffic is heavy, master may disconnect with
replicas and can't finish synchronization with replica. If we set client-output-buffer-limit big,
master may be OOM when there are many replicas that separately keep much memory.
Because replication buffers of different replica client are the same, one simple idea is that
all replicas only use one replication buffer, that will effectively save memory.
Since replication backlog content is the same as replicas' output buffer, now we
can discard replication backlog memory and use global shared replication buffer
to implement replication backlog mechanism.
## Implementation
I create one global "replication buffer" which contains content of replication stream.
The structure of "replication buffer" is similar to the reply list that exists in every client.
But the node of list is `replBufBlock`, which has `id, repl_offset, refcount` fields.
```c
/* Replication buffer blocks is the list of replBufBlock.
*
* +--------------+ +--------------+ +--------------+
* | refcount = 1 | ... | refcount = 0 | ... | refcount = 2 |
* +--------------+ +--------------+ +--------------+
* | / \
* | / \
* | / \
* Repl Backlog Replia_A Replia_B
*
* Each replica or replication backlog increments only the refcount of the
* 'ref_repl_buf_node' which it points to. So when replica walks to the next
* node, it should first increase the next node's refcount, and when we trim
* the replication buffer nodes, we remove node always from the head node which
* refcount is 0. If the refcount of the head node is not 0, we must stop
* trimming and never iterate the next node. */
/* Similar with 'clientReplyBlock', it is used for shared buffers between
* all replica clients and replication backlog. */
typedef struct replBufBlock {
int refcount; /* Number of replicas or repl backlog using. */
long long id; /* The unique incremental number. */
long long repl_offset; /* Start replication offset of the block. */
size_t size, used;
char buf[];
} replBufBlock;
```
So now when we feed replication stream into replication backlog and all replicas, we only need
to feed stream into replication buffer `feedReplicationBuffer`. In this function, we set some fields of
replication backlog and replicas to references of the global replication buffer blocks. And we also
need to check replicas' output buffer limit to free if exceeding `client-output-buffer-limit`, and trim
replication backlog if exceeding `repl-backlog-size`.
When sending reply to replicas, we also need to iterate replication buffer blocks and send its
content, when totally sending one block for replica, we decrease current node count and
increase the next current node count, and then free the block which reference is 0 from the
head of replication buffer blocks.
Since now we use linked list to manage replication backlog, it may cost much time for iterating
all linked list nodes to find corresponding replication buffer node. So we create a rax tree to
store some nodes for index, but to avoid rax tree occupying too much memory, i record
one per 64 nodes for index.
Currently, to make partial resynchronization as possible as much, we always let replication
backlog as the last reference of replication buffer blocks, backlog size may exceeds our setting
if slow replicas that reference vast replication buffer blocks, and this method doesn't increase
memory usage since they share replication buffer. To avoid freezing server for freeing unreferenced
replication buffer blocks when we need to trim backlog for exceeding backlog size setting,
we trim backlog incrementally (free 64 blocks per call now), and make it faster in
`beforeSleep` (free 640 blocks).
### Other changes
- `mem_total_replication_buffers`: we add this field in INFO command, it means the total
memory of replication buffers used.
- `mem_clients_slaves`: now even replica is slow to replicate, and its output buffer memory
is not 0, but it still may be 0, since replication backlog and replicas share one global replication
buffer, only if replication buffer memory is more than the repl backlog setting size, we consider
the excess as replicas' memory. Otherwise, we think replication buffer memory is the consumption
of repl backlog.
- Key eviction
Since all replicas and replication backlog share global replication buffer, we think only the
part of exceeding backlog size the extra separate consumption of replicas.
Because we trim backlog incrementally in the background, backlog size may exceeds our
setting if slow replicas that reference vast replication buffer blocks disconnect.
To avoid massive eviction loop, we don't count the delayed freed replication backlog into
used memory even if there are no replicas, i.e. we also regard this memory as replicas's memory.
- `client-output-buffer-limit` check for replica clients
It doesn't make sense to set the replica clients output buffer limit lower than the repl-backlog-size
config (partial sync will succeed and then replica will get disconnected). Such a configuration is
ignored (the size of repl-backlog-size will be used). This doesn't have memory consumption
implications since the replica client will share the backlog buffers memory.
- Drop replication backlog after loading data if needed
We always create replication backlog if server is a master, we need it because we put DELs in
it when loading expired keys in RDB, but if RDB doesn't have replication info or there is no rdb,
it is not possible to support partial resynchronization, to avoid extra memory of replication backlog,
we drop it.
- Multi IO threads
Since all replicas and replication backlog use global replication buffer, if I/O threads are enabled,
to guarantee data accessing thread safe, we must let main thread handle sending the output buffer
to all replicas. But before, other IO threads could handle sending output buffer of all replicas.
## Other optimizations
This solution resolve some other problem:
- When replicas disconnect with master since of out of output buffer limit, releasing the output
buffer of replicas may freeze server if we set big `client-output-buffer-limit` for replicas, but now,
it doesn't cause freezing.
- This implementation may mitigate reply list copy cost time(also freezes server) when one replication
has huge reply buffer and another replica can copy buffer for full synchronization. now, we just copy
reference info, it is very light.
- If we set replication backlog size big, it also may cost much time to copy replication backlog into
replica's output buffer. But this commit eliminates this problem.
- Resizing replication backlog size doesn't empty current replication backlog content.
I moved a bunch of stats in redisFork to be executed only on successful
fork, since they seem wrong to be done when it failed.
I guess when fork fails it does that immediately, no latency spike.
Following #9483 the daily CI exposed a few problems.
* The cluster creation code (uses redis-cli) is complicated to test with TLS enabled.
for now i'm just skipping them since the tests we run there don't really need that kind of coverage
* cluster port binding failures
note that `find_available_port` already looks for a free cluster port
but the code in `wait_server_started` couldn't detect the failure of binding
(the text it greps for wasn't found in the log)
## Intro
The purpose is to allow having different flags/ACL categories for
subcommands (Example: CONFIG GET is ok-loading but CONFIG SET isn't)
We create a small command table for every command that has subcommands
and each subcommand has its own flags, etc. (same as a "regular" command)
This commit also unites the Redis and the Sentinel command tables
## Affected commands
CONFIG
Used to have "admin ok-loading ok-stale no-script"
Changes:
1. Dropped "ok-loading" in all except GET (this doesn't change behavior since
there were checks in the code doing that)
XINFO
Used to have "read-only random"
Changes:
1. Dropped "random" in all except CONSUMERS
XGROUP
Used to have "write use-memory"
Changes:
1. Dropped "use-memory" in all except CREATE and CREATECONSUMER
COMMAND
No changes.
MEMORY
Used to have "random read-only"
Changes:
1. Dropped "random" in PURGE and USAGE
ACL
Used to have "admin no-script ok-loading ok-stale"
Changes:
1. Dropped "admin" in WHOAMI, GENPASS, and CAT
LATENCY
No changes.
MODULE
No changes.
SLOWLOG
Used to have "admin random ok-loading ok-stale"
Changes:
1. Dropped "random" in RESET
OBJECT
Used to have "read-only random"
Changes:
1. Dropped "random" in ENCODING and REFCOUNT
SCRIPT
Used to have "may-replicate no-script"
Changes:
1. Dropped "may-replicate" in all except FLUSH and LOAD
CLIENT
Used to have "admin no-script random ok-loading ok-stale"
Changes:
1. Dropped "random" in all except INFO and LIST
2. Dropped "admin" in ID, TRACKING, CACHING, GETREDIR, INFO, SETNAME, GETNAME, and REPLY
STRALGO
No changes.
PUBSUB
No changes.
CLUSTER
Changes:
1. Dropped "admin in countkeysinslots, getkeysinslot, info, nodes, keyslot, myid, and slots
SENTINEL
No changes.
(note that DEBUG also fits, but we decided not to convert it since it's for
debugging and anyway undocumented)
## New sub-command
This commit adds another element to the per-command output of COMMAND,
describing the list of subcommands, if any (in the same structure as "regular" commands)
Also, it adds a new subcommand:
```
COMMAND LIST [FILTERBY (MODULE <module-name>|ACLCAT <cat>|PATTERN <pattern>)]
```
which returns a set of all commands (unless filters), but excluding subcommands.
## Module API
A new module API, RM_CreateSubcommand, was added, in order to allow
module writer to define subcommands
## ACL changes:
1. Now, that each subcommand is actually a command, each has its own ACL id.
2. The old mechanism of allowed_subcommands is redundant
(blocking/allowing a subcommand is the same as blocking/allowing a regular command),
but we had to keep it, to support the widespread usage of allowed_subcommands
to block commands with certain args, that aren't subcommands (e.g. "-select +select|0").
3. I have renamed allowed_subcommands to allowed_firstargs to emphasize the difference.
4. Because subcommands are commands in ACL too, you can now use "-" to block subcommands
(e.g. "+client -client|kill"), which wasn't possible in the past.
5. It is also possible to use the allowed_firstargs mechanism with subcommand.
For example: `+config -config|set +config|set|loglevel` will block all CONFIG SET except
for setting the log level.
6. All of the ACL changes above required some amount of refactoring.
## Misc
1. There are two approaches: Either each subcommand has its own function or all
subcommands use the same function, determining what to do according to argv[0].
For now, I took the former approaches only with CONFIG and COMMAND,
while other commands use the latter approach (for smaller blamelog diff).
2. Deleted memoryGetKeys: It is no longer needed because MEMORY USAGE now uses the "range" key spec.
4. Bugfix: GETNAME was missing from CLIENT's help message.
5. Sentinel and Redis now use the same table, with the same function pointer.
Some commands have a different implementation in Sentinel, so we redirect
them (these are ROLE, PUBLISH, and INFO).
6. Command stats now show the stats per subcommand (e.g. instead of stats just
for "config" you will have stats for "config|set", "config|get", etc.)
7. It is now possible to use COMMAND directly on subcommands:
COMMAND INFO CONFIG|GET (The pipeline syntax was inspired from ACL, and
can be used in functions lookupCommandBySds and lookupCommandByCString)
8. STRALGO is now a container command (has "help")
## Breaking changes:
1. Command stats now show the stats per subcommand (see (5) above)
Since the size of mode_t is platform dependant we handle the
`unixsocketperm` configuration as a generic int type.
mode_t is either an unsigned int or unsigned short (macOS) and
the range-limits allows for a simple cast to a mode_t.
Tracking invalidation messages were sometimes sent in inconsistent order,
before the command's reply rather than after.
In addition to that, they were sometimes embedded inside other commands
responses, like MULTI-EXEC and MGET.
Implement createPipe() to combine creating pipe and setting flags, also reduce
system calls by prioritizing pipe2() over pipe().
Without createPipe(), we have to call pipe() to create a pipe and then call some
functions (like anetCloexec() and anetNonBlock()) of anet.c to set flags respectively,
which leads to some extra system calls, now we can leverage pipe2() to combine
them and make the process of creating pipe more convergent in createPipe().
Co-authored-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
Co-authored-by: Oran Agra <oran@redislabs.com>
The new value indicates how long Redis wait to
acquire the GIL after sleep. This can help identify
problems where a module perform some background
operation for a long time (with the GIL held) and
blocks the Redis main thread.
Scenario:
1. client block on command `XREAD BLOCK 0 STREAMS mystream $`
2. in a module, calling `XADD mystream * field value` via lua from a timer callback
3. client will receive response after some latency up to 100ms
Reason:
When `XADD` signal the key `mystream` as ready, `beforeSleep` in next eventloop will call
`handleClientsBlockedOnKeys` to unblock the client and add pending data to write but not
actually install a write handler, so next redis will block in `aeApiPoll` up to 100ms given `hz`
config as default 10, pending data will be sent in another next eventloop by
`handleClientsWithPendingWritesUsingThreads`.
Calling `handleClientsBlockedOnKeys` before `handleClientsWithPendingWritesUsingThreads`
in `beforeSleep` solves the problem.
This change sets a low limit for multibulk and bulk length in the
protocol for unauthenticated connections, so that they can't easily
cause redis to allocate massive amounts of memory by sending just a few
characters on the network.
The new limits are 10 arguments of 16kb each (instead of 1m of 512mb)
Fixing CI test issues introduced in #8687
- valgrind warnings in readQueryFromClient when client was freed by processInputBuffer
- adding DEBUG pause-cron for tests not to be time dependent.
- skipping a test that depends on socket buffers / events not compatible with TLS
- making sure client got subscribed by not using deferring client
### Description
A mechanism for disconnecting clients when the sum of all connected clients is above a
configured limit. This prevents eviction or OOM caused by accumulated used memory
between all clients. It's a complimentary mechanism to the `client-output-buffer-limit`
mechanism which takes into account not only a single client and not only output buffers
but rather all memory used by all clients.
#### Design
The general design is as following:
* We track memory usage of each client, taking into account all memory used by the
client (query buffer, output buffer, parsed arguments, etc...). This is kept up to date
after reading from the socket, after processing commands and after writing to the socket.
* Based on the used memory we sort all clients into buckets. Each bucket contains all
clients using up up to x2 memory of the clients in the bucket below it. For example up
to 1m clients, up to 2m clients, up to 4m clients, ...
* Before processing a command and before sleep we check if we're over the configured
limit. If we are we start disconnecting clients from larger buckets downwards until we're
under the limit.
#### Config
`maxmemory-clients` max memory all clients are allowed to consume, above this threshold
we disconnect clients.
This config can either be set to 0 (meaning no limit), a size in bytes (possibly with MB/GB
suffix), or as a percentage of `maxmemory` by using the `%` suffix (e.g. setting it to `10%`
would mean 10% of `maxmemory`).
#### Important code changes
* During the development I encountered yet more situations where our io-threads access
global vars. And needed to fix them. I also had to handle keeps the clients sorted into the
memory buckets (which are global) while their memory usage changes in the io-thread.
To achieve this I decided to simplify how we check if we're in an io-thread and make it
much more explicit. I removed the `CLIENT_PENDING_READ` flag used for checking
if the client is in an io-thread (it wasn't used for anything else) and just used the global
`io_threads_op` variable the same way to check during writes.
* I optimized the cleanup of the client from the `clients_pending_read` list on client freeing.
We now store a pointer in the `client` struct to this list so we don't need to search in it
(`pending_read_list_node`).
* Added `evicted_clients` stat to `INFO` command.
* Added `CLIENT NO-EVICT ON|OFF` sub command to exclude a specific client from the
client eviction mechanism. Added corrosponding 'e' flag in the client info string.
* Added `multi-mem` field in the client info string to show how much memory is used up
by buffered multi commands.
* Client `tot-mem` now accounts for buffered multi-commands, pubsub patterns and
channels (partially), tracking prefixes (partially).
* CLIENT_CLOSE_ASAP flag is now handled in a new `beforeNextClient()` function so
clients will be disconnected between processing different clients and not only before sleep.
This new function can be used in the future for work we want to do outside the command
processing loop but don't want to wait for all clients to be processed before we get to it.
Specifically I wanted to handle output-buffer-limit related closing before we process client
eviction in case the two race with each other.
* Added a `DEBUG CLIENT-EVICTION` command to print out info about the client eviction
buckets.
* Each client now holds a pointer to the client eviction memory usage bucket it belongs to
and listNode to itself in that bucket for quick removal.
* Global `io_threads_op` variable now can contain a `IO_THREADS_OP_IDLE` value
indicating no io-threading is currently being executed.
* In order to track memory used by each clients in real-time we can't rely on updating
these stats in `clientsCron()` alone anymore. So now I call `updateClientMemUsage()`
(used to be `clientsCronTrackClientsMemUsage()`) after command processing, after
writing data to pubsub clients, after writing the output buffer and after reading from the
socket (and maybe other places too). The function is written to be fast.
* Clients are evicted if needed (with appropriate log line) in `beforeSleep()` and before
processing a command (before performing oom-checks and key-eviction).
* All clients memory usage buckets are grouped as follows:
* All clients using less than 64k.
* 64K..128K
* 128K..256K
* ...
* 2G..4G
* All clients using 4g and up.
* Added client-eviction.tcl with a bunch of tests for the new mechanism.
* Extended maxmemory.tcl to test the interaction between maxmemory and
maxmemory-clients settings.
* Added an option to flag a numeric configuration variable as a "percent", this means that
if we encounter a '%' after the number in the config file (or config set command) we
consider it as valid. Such a number is store internally as a negative value. This way an
integer value can be interpreted as either a percent (negative) or absolute value (positive).
This is useful for example if some numeric configuration can optionally be set to a percentage
of something else.
Co-authored-by: Oran Agra <oran@redislabs.com>
This commit introduced a new flag to the RM_Call:
'C' - Check if the command can be executed according to the ACLs associated with it.
Also, three new API's added to check if a command, key, or channel can be executed or accessed
by a user, according to the ACLs associated with it.
- RM_ACLCheckCommandPerm
- RM_ACLCheckKeyPerm
- RM_ACLCheckChannelPerm
The user for these API's is a RedisModuleUser object, that for a Module user returned by the RM_CreateModuleUser API, or for a general ACL user can be retrieved by these two new API's:
- RM_GetCurrentUserName - Retrieve the user name of the client connection behind the current context.
- RM_GetModuleUserFromUserName - Get a RedisModuleUser from a user name
As a result of getting a RedisModuleUser from name, it can now also access the general ACL users (not just ones created by the module).
This mean the already existing API RM_SetModuleUserACL(), can be used to change the ACL rules for such users.
This is similar to the recent addition of LMPOP/BLMPOP (#9373), but zset.
Syntax for the new ZMPOP command:
`ZMPOP numkeys [<key> ...] MIN|MAX [COUNT count]`
Syntax for the new BZMPOP command:
`BZMPOP timeout numkeys [<key> ...] MIN|MAX [COUNT count]`
Some background:
- ZPOPMIN/ZPOPMAX take only one key, and can return multiple elements.
- BZPOPMIN/BZPOPMAX take multiple keys, but return only one element from just one key.
- ZMPOP/BZMPOP can take multiple keys, and can return multiple elements from just one key.
Note that ZMPOP/BZMPOP can take multiple keys, it eventually operates on just on key.
And it will propagate as ZPOPMIN or ZPOPMAX with the COUNT option.
As new commands, if we can not pop any elements, the response like:
- ZMPOP: Return a NIL in both RESP2 and RESP3, unlike ZPOPMIN/ZPOPMAX return emptyarray.
- BZMPOP: Return a NIL in both RESP2 and RESP3 when timeout is reached, like BZPOPMIN/BZPOPMAX.
For the normal response is nested arrays in RESP2 and RESP3:
```
ZMPOP/BZMPOP
1) keyname
2) 1) 1) member1
2) score1
2) 1) member2
2) score2
In RESP2:
1) "myzset"
2) 1) 1) "three"
2) "3"
2) 1) "two"
2) "2"
In RESP3:
1) "myzset"
2) 1) 1) "three"
2) (double) 3
2) 1) "two"
2) (double) 2
```
Implements the [LIMIT limit] variant of SINTERCARD/ZINTERCARD.
Now with the LIMIT, we can stop the searching when cardinality
reaching the limit, and return the cardinality ASAP.
Note that in SINTERCARD, the old synatx was: `SINTERCARD key [key ...]`
In order to add a optional parameter, we must break the old synatx.
So the new syntax of SINTERCARD will be consistent with ZINTERCARD.
New syntax: `SINTERCARD numkeys key [key ...] [LIMIT limit]`.
Note that this means that SINTERCARD has a different syntax than
SINTER and SINTERSTORE (taking numkeys argument)
As for ZINTERCARD, we can easily add a optional parameter to it.
New syntax: `ZINTERCARD numkeys key [key ...] [LIMIT limit]`
The `cmd` argument was completely unused, and all the code that bothered to pass it was unnecessary.
This is a prepartion for a future commit that treats subcommands as commands
Fix#7297
The problem:
Today, there is no way for a client library or app to know the key name indexes for commands such as
ZUNIONSTORE/EVAL and others with "numkeys", since COMMAND INFO returns no useful info for them.
For cluster-aware redis clients, this requires to 'patch' the client library code specifically for each of these commands or to
resolve each execution of these commands with COMMAND GETKEYS.
The solution:
Introducing key specs other than the legacy "range" (first,last,step)
The 8th element of the command info array, if exists, holds an array of key specs. The array may be empty, which indicates
the command doesn't take any key arguments or may contain one or more key-specs, each one may leads to the discovery
of 0 or more key arguments.
A client library that doesn't support this key-spec feature will keep using the first,last,step and movablekeys flag which will
obviously remain unchanged.
A client that supports this key-specs feature needs only to look at the key-specs array. If it finds an unrecognized spec, it
must resort to using COMMAND GETKEYS if it wishes to get all key name arguments, but if all it needs is one key in order
to know which cluster node to use, then maybe another spec (if the command has several) can supply that, and there's no
need to use GETKEYS.
Each spec is an array of arguments, first one is the spec name, the second is an array of flags, and the third is an array
containing details about the spec (specific meaning for each spec type)
The initial flags we support are "read" and "write" indicating if the keys that this key-spec finds are used for read or for write.
clients should ignore any unfamiliar flags.
In order to easily find the positions of keys in a given array of args we introduce keys specs. There are two logical steps of
key specs:
1. `start_search`: Given an array of args, indicate where we should start searching for keys
2. `find_keys`: Given the output of start_search and an array of args, indicate all possible indices of keys.
### start_search step specs
- `index`: specify an argument index explicitly
- `index`: 0 based index (1 means the first command argument)
- `keyword`: specify a string to match in `argv`. We should start searching for keys just after the keyword appears.
- `keyword`: the string to search for
- `start_search`: an index from which to start the keyword search (can be negative, which means to search from the end)
Examples:
- `SET` has start_search of type `index` with value `1`
- `XREAD` has start_search of type `keyword` with value `[“STREAMS”,1]`
- `MIGRATE` has start_search of type `keyword` with value `[“KEYS”,-2]`
### find_keys step specs
- `range`: specify `[count, step, limit]`.
- `lastkey`: index of the last key. relative to the index returned from begin_search. -1 indicating till the last argument, -2 one before the last
- `step`: how many args should we skip after finding a key, in order to find the next one
- `limit`: if count is -1, we use limit to stop the search by a factor. 0 and 1 mean no limit. 2 means ½ of the remaining args, 3 means ⅓, and so on.
- “keynum”: specify `[keynum_index, first_key_index, step]`.
- `keynum_index`: is relative to the return of the `start_search` spec.
- `first_key_index`: is relative to `keynum_index`.
- `step`: how many args should we skip after finding a key, in order to find the next one
Examples:
- `SET` has `range` of `[0,1,0]`
- `MSET` has `range` of `[-1,2,0]`
- `XREAD` has `range` of `[-1,1,2]`
- `ZUNION` has `start_search` of type `index` with value `1` and `find_keys` of type `keynum` with value `[0,1,1]`
- `AI.DAGRUN` has `start_search` of type `keyword` with value `[“LOAD“,1]` and `find_keys` of type `keynum` with value
`[0,1,1]` (see https://oss.redislabs.com/redisai/master/commands/#aidagrun)
Note: this solution is not perfect as the module writers can come up with anything, but at least we will be able to find the key
args of the vast majority of commands.
If one of the above specs can’t describe the key positions, the module writer can always fall back to the `getkeys-api` option.
Some keys cannot be found easily (`KEYS` in `MIGRATE`: Imagine the argument for `AUTH` is the string “KEYS” - we will
start searching in the wrong index).
The guarantee is that the specs may be incomplete (`incomplete` will be specified in the spec to denote that) but we never
report false information (assuming the command syntax is correct).
For `MIGRATE` we start searching from the end - `startfrom=-1` - and if one of the keys is actually called "keys" we will
report only a subset of all keys - hence the `incomplete` flag.
Some `incomplete` specs can be completely empty (i.e. UNKNOWN begin_search) which should tell the client that
COMMAND GETKEYS (or any other way to get the keys) must be used (Example: For `SORT` there is no way to describe
the STORE keyword spec, as the word "store" can appear anywhere in the command).
We will expose these key specs in the `COMMAND` command so that clients can learn, on startup, where the keys are for
all commands instead of holding hardcoded tables or use `COMMAND GETKEYS` in runtime.
Comments:
1. Redis doesn't internally use the new specs, they are only used for COMMAND output.
2. In order to support the current COMMAND INFO format (reply array indices 4, 5, 6) we created a synthetic range, called
legacy_range, that, if possible, is built according to the new specs.
3. Redis currently uses only getkeys_proc or the legacy_range to get the keys indices (in COMMAND GETKEYS for
example).
"incomplete" specs:
the command we have issues with are MIGRATE, STRALGO, and SORT
for MIGRATE, because the token KEYS, if exists, must be the last token, we can search in reverse. it one of the keys is
actually the string "keys" will return just a subset of the keys (hence, it's "incomplete")
for SORT and STRALGO we can use this heuristic (the keys can be anywhere in the command) and therefore we added a
key spec that is both "incomplete" and of "unknown type"
if a client encounters an "incomplete" spec it means that it must find a different way (either COMMAND GETKEYS or have
its own parser) to retrieve the keys.
please note that all commands, apart from the three mentioned above, have "complete" key specs
The main idea is how to allow a master to load replication info from RDB file when rebooting, if master can load replication info it means that replicas may have the chance to psync with master, it can save much traffic.
The key point is we need guarantee safety and consistency, so there
are two differences between master and replica:
1. master would load the replication info as secondary ID and
offset, in case other masters have the same replid.
2. when master loading RDB, it would propagate expired keys as DEL
command to replication backlog, then replica can receive these
commands to delete stale keys.
p.s. the expired keys when RDB loading is useful for users, so
we show it as `rdb_last_load_keys_expired` and `rdb_last_load_keys_loaded` in info persistence.
Moreover, after load replication info, master should update
`no_replica_time` in case loading RDB cost too long time.
A write request may be paused unexpectedly because `server.client_pause_end_time` is old.
**Recreate this:**
redis-cli -p 6379
127.0.0.1:6379> client pause 500000000 write
OK
127.0.0.1:6379> client unpause
OK
127.0.0.1:6379> client pause 10000 write
OK
127.0.0.1:6379> set key value
The write request `set key value` is paused util the timeout of 500000000 milliseconds was reached.
**Fix:**
reset `server.client_pause_end_time` = 0 in `unpauseClients`
We want to add COUNT option for BLPOP.
But we can't do it without breaking compatibility due to the command arguments syntax.
So this commit introduce two new commands.
Syntax for the new LMPOP command:
`LMPOP numkeys [<key> ...] LEFT|RIGHT [COUNT count]`
Syntax for the new BLMPOP command:
`BLMPOP timeout numkeys [<key> ...] LEFT|RIGHT [COUNT count]`
Some background:
- LPOP takes one key, and can return multiple elements.
- BLPOP takes multiple keys, but returns one element from just one key.
- LMPOP can take multiple keys and return multiple elements from just one key.
Note that LMPOP/BLMPOP can take multiple keys, it eventually operates on just one key.
And it will propagate as LPOP or RPOP with the COUNT option.
As a new command, it still return NIL if we can't pop any elements.
For the normal response is nested arrays in RESP2 and RESP3, like:
```
LMPOP/BLMPOP
1) keyname
2) 1) element1
2) element2
```
I.e. unlike BLPOP that returns a key name and one element so it uses a flat array,
and LPOP that returns multiple elements with no key name, and again uses a flat array,
this one has to return a nested array, and it does for for both RESP2 and RESP3 (like SCAN does)
Some discuss can see: #766#8824
Add two INFO metrics:
```
total_active_defrag_time:12345
current_active_defrag_time:456
```
`current_active_defrag_time` if greater than 0, means how much time has
passed since active defrag started running. If active defrag stops, this metric is reset to 0.
`total_active_defrag_time` means total time the fragmentation
was over the defrag threshold since the server started.
This is a followup PR for #9031
When a replica paused, it would not apply any commands event the command comes from master, if we feed the non-applied command to replication stream, the replication offset would be wrong, and data would be lost after failover(since replica's `master_repl_offset` grows but command is not applied).
To fix it, here are the changes:
* Don't update replica's replication offset or propagate commands to sub-replicas when it's paused in `commandProcessed`.
* Show `slave_read_repl_offset` in info reply.
* Add an assert to make sure master client should never be blocked unless pause or module (some modules may use block way to do background (parallel) processing and forward original block module command to the replica, it's not a good way but it can work, so the assert excludes module now, but someday in future all modules should rewrite block command to propagate like what `BLPOP` does).
1. MIGRATE has a potnetial key arg in argv[3]. It should be reflected in the command table.
2. getKeysUsingCommandTable should never free getKeysResult, it is always freed by the caller)
The reason we never encountered this double-free bug is that almost always getKeysResult
uses the statis buffer and doesn't allocate a new one.
* Enhance dict to support arbitrary metadata carried in dictEntry
Co-authored-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
* Rewrite slot-to-keys mapping to linked lists using dict entry metadata
This is a memory enhancement for Redis Cluster.
The radix tree slots_to_keys (which duplicates all key names prefixed with their
slot number) is replaced with a linked list for each slot. The dict entries of
the same cluster slot form a linked list and the pointers are stored as metadata
in each dict entry of the main DB dict.
This commit also moves the slot-to-key API from db.c to cluster.c.
Co-authored-by: Jim Brunner <brunnerj@amazon.com>
When `decr_step` is greater than `oldlimit`, the final `bestlimit` may be invalid.
For example, oldlimit = 10, decr_step = 16.
Current bestlimit = 15 and setrlimit() failed. Since bestlimit is less than decr_step , then exit the loop.
The final bestlimit is larger than oldlimit but is invalid.
Note that this only matters if the system fd limit is below 16, so unlikely to have any actual effect.
The order of setting things up follows some reasoning: Setup signal
handlers first because a signal could fire at any time. Adjust OOM score
before everything else to assist the OOM killer if memory resources are
low.
The trigger for this is a valgrind test failure which resulted with the
child catching a SIGUSR1 before initializing the handler.
Part one of implementing #8702 (taking hashes first before other types)
## Description of the feature
1. Change ziplist encoded hash objects to listpack encoding.
2. Convert existing ziplists on RDB loading time. an O(n) operation.
## Rdb format changes
1. Add RDB_TYPE_HASH_LISTPACK rdb type.
2. Bump RDB_VERSION to 10
## Interface changes
1. New `hash-max-listpack-entries` config is an alias for `hash-max-ziplist-entries` (same with `hash-max-listpack-value`)
2. OBJECT ENCODING will return `listpack` instead of `ziplist`
## Listpack improvements:
1. Support direct insert, replace integer element (rather than convert back and forth from string)
3. Add more listpack capabilities to match the ziplist ones (like `lpFind`, `lpRandomPairs` and such)
4. Optimize element length fetching, avoid multiple calculations
5. Use inline to avoid function call overhead.
## Tests
1. Add a new test to the RDB load time conversion
2. Adding the listpack unit tests. (based on the one in ziplist.c)
3. Add a few "corrupt payload: fuzzer findings" tests, and slightly modify existing ones.
Co-authored-by: Oran Agra <oran@redislabs.com>
Reduce dict struct memory overhead
on 64bit dict size goes down from jemalloc's 96 byte bin to its 56 byte bin.
summary of changes:
- Remove `privdata` from callbacks and dict creation. (this affects many files, see "Interface change" below).
- Meld `dictht` struct into the `dict` struct to eliminate struct padding. (this affects just dict.c and defrag.c)
- Eliminate the `sizemask` field, can be calculated from size when needed.
- Convert the `size` field into `size_exp` (exponent), utilizes one byte instead of 8.
Interface change: pass dict pointer to dict type call back functions.
This is instead of passing the removed privdata field. In the future if
we'd like to have private data in the callbacks we can extract it from
the dict type. We can extend dictType to include a custom dict struct
allocator and use it to allocate more data at the end of the dict
struct. This data can then be used to store private data later acccessed
by the callbacks.
## Backgroud
As we know, after `fork`, one process will copy pages when writing data to these
pages(CoW), and another process still keep old pages, they totally cost more memory.
For redis, we suffered that redis consumed much memory when the fork child is serializing
key/values, even that maybe cause OOM.
But actually we find, in redis fork child process, the child process don't need to keep some
memory and parent process may write or update that, for example, child process will never
access the key-value that is serialized but users may update it in parent process.
So we think it may reduce COW if the child process release memory that it is not needed.
## Implementation
For releasing key value in child process, we may think we call `decrRefCount` to free memory,
but i find the fork child process still use much memory when we don't write any data to redis,
and it costs much more time that slows down bgsave. Maybe because memory allocator doesn't
really release memory to OS, and it may modify some inner data for this free operation, especially
when we free small objects.
Moreover, CoW is based on pages, so it is a easy way that we only free the memory bulk that is
not less than kernel page size. madvise(MADV_DONTNEED) can quickly release specified region
pages to OS bypassing memory allocator, and allocator still consider that this memory still is used
and don't change its inner data.
There are some buffers we can release in the fork child process:
- **Serialized key-values**
the fork child process never access serialized key-values, so we try to free them.
Because we only can release big bulk memory, and it is time consumed to iterate all
items/members/fields/entries of complex data type. So we decide to iterate them and
try to release them only when their average size of item/member/field/entry is more
than page size of OS.
- **Replication backlog**
Because replication backlog is a cycle buffer, it will be changed quickly if redis has heavy
write traffic, but in fork child process, we don't need to access that.
- **Client buffers**
If clients have requests during having the fork child process, clients' buffer also be changed
frequently. The memory includes client query buffer, output buffer, and client struct used memory.
To get child process peak private dirty memory, we need to count peak memory instead
of last used memory, because the child process may continue to release memory (since
COW used to only grow till now, the last was equivalent to the peak).
Also we're adding a new `current_cow_peak` info variable (to complement the existing
`current_cow_size`)
Co-authored-by: Oran Agra <oran@redislabs.com>
Add SINTERCARD and ZINTERCARD commands that are similar to
ZINTER and SINTER but only return the cardinality with minimum
processing and memory overheads.
Co-authored-by: Oran Agra <oran@redislabs.com>
1. In sendBulkToSlave, we used LL_VERBOSE in the past, changed to
LL_WARNING. (all the other places that do freeClient(slave) use LL_WARNING)
2. The old style LOG_WARNING, chang it to LL_WARNING. Introduced in an
old pr (#1690).
Add NX, XX, GT, and LT flags to EXPIRE, PEXPIRE, EXPIREAT, PEXAPIREAT.
- NX - only modify the TTL if no TTL is currently set
- XX - only modify the TTL if there is a TTL currently set
- GT - only increase the TTL (considering non-volatile keys as infinite expire time)
- LT - only decrease the TTL (considering non-volatile keys as infinite expire time)
return value of the command is 0 when the operation was skipped due to one of these flags.
Signed-off-by: Ning Sun <sunng@protonmail.com>
Add two INFO metrics:
```
total_eviction_exceeded_time:69734
current_eviction_exceeded_time:10230
```
`current_eviction_exceeded_time` if greater than 0, means how much time current used memory is greater than `maxmemory`. And we are still over the maxmemory. If used memory is below `maxmemory`, this metric is reset to 0.
`total_eviction_exceeded_time` means total time used memory is greater than `maxmemory` since server startup.
The units of these two metrics are ms.
Co-authored-by: Oran Agra <oran@redislabs.com>
- SELECT and WAIT don't read or write from the keyspace (unlike DEL, EXISTS, EXPIRE, DBSIZE, KEYS, etc).
they're more similar to AUTH and HELLO (and maybe PING and COMMAND).
they only affect the current connection, not the server state, so they should be `@connection`, not `@keyspace`
- ROLE, like LASTSAVE is `@admin` (and `@dangerous` like INFO)
- ASKING, READONLY, READWRITE are `@connection` too (not `@keyspace`)
- Additionally, i'm now documenting the exact meaning of each ACL category so it's clearer which commands belong where.
There are two issues fixed in this commit:
1. we want to fail the EXEC command in case there is a watched key that's logically
expired but not yet deleted by active expire or lazy expire.
2. we saw that currently cache time is update in every `call()` (including nested calls),
this time is being also being use for the isKeyExpired comparison, we want to update
the cache time only in the first call (execCommand)
Co-authored-by: Oran Agra <oran@redislabs.com>
redis-check-aof/redis-check-rdb.
Related to #9176. Before this commit, redis-server starts as
redis-check-aof/redis-check-rdb if the directory it is started from
contains the string redis-check-aof/redis-check-rdb. We check the
executable name instead of directory.
when tracking the peak, don't reset the peak to 0, reset it to the
maximum of the current used, and the planned to be used by the current
arg.
when shrining, split the two separate conditions.
the idle time shrinking will remove all free space.
but the peak based shrinking will keep room for the current arg.
when we resize due to a peak (rahter than idle time), don't trim all
unused space, let the qbuf keep a size that's sufficient for the
currently process bulklen, and the current peak.
Co-authored-by: sundb <sundbcn@gmail.com>
Co-authored-by: yoav-steinberg <yoav@monfort.co.il>
1. querybuf_peak has not been updated correctly in readQueryFromClient.
2. qbuf shrinking uses sdsalloc instead of sdsAllocSize
see more details in issue #4983
Before this commit, redis-server starts in sentinel mode if the first startup
argument has the string redis-sentinel, so redis also starts in sentinel mode
if the directory it was started from contains the string redis-sentinel.
Now we check the executable name instead of directory.
Some examples:
1. Execute ./redis-sentinel/redis/src/redis-sentinel, starts in sentinel mode.
2. Execute ./redis-sentinel/redis/src/redis-server, starts in server mode,
but before, redis will start in sentinel mode.
3. Execute ./redis-sentinel/redis/src/redis-server --sentinel, of course, like
before, starts in sentinel mode.
In the past, the first bind address that was explicitly specified was
also used to bind outgoing connections. This could result with some
problems. For example: on some systems using `bind 127.0.0.1` would
result with outgoing connections also binding to `127.0.0.1` and failing
to connect to remote addresses.
With the recent change to the way `bind` is handled, this presented
other issues:
* The default first bind address is '*' which is not a valid address.
* We make no distinction between user-supplied config that is identical
to the default, and the default config.
This commit addresses both these issues by introducing an explicit
configuration parameter to control the bind address on outgoing
connections.
* Specifying an empty `bind ""` configuration prevents Redis from listening on any TCP port. Before this commit, such configuration was not accepted.
* Using `CONFIG GET bind` will always return an explicit configuration value. Before this commit, if a bind address was not specified the returned value was empty (which was an anomaly).
Another behavior change is that modifying the `bind` configuration to a non-default value will NO LONGER DISABLE protected-mode implicitly.
* Cleaning up the cluster interface by moving almost all related declarations into cluster.h
(no logic change -- just moving declarations/definitions around)
This initial effort leaves two items out of scope - the configuration parsing into the server
struct and the internals exposed by the clusterNode struct.
* Remove unneeded declarations of dictSds*
Ideally all the dictSds functionality would move from server.c into a dedicated module
so we can avoid the duplication in redis-benchmark/cli
* Move crc16 back into server.h, will be moved out once we create a seperate header file for
hashing functions
The initialize memory of `querybuf` is `PROTO_IOBUF_LEN(1024*16) * 2` (due to sdsMakeRoomFor being greedy), under `jemalloc`, the allocated memory will be 40k.
This will most likely result in the `querybuf` being resized when call `clientsCronResizeQueryBuffer` unless the client requests it fast enough.
Note that this bug existed even before #7875, since the condition for resizing includes the sds headers (32k+6).
## Changes
1. Use non-greedy sdsMakeRoomFor when allocating the initial query buffer (of 16k).
1. Also use non-greedy allocation when working with BIG_ARG (we won't use that extra space anyway)
2. in case we did use a greedy allocation, read as much as we can into the buffer we got (including internal frag), to reduce system calls.
3. introduce a dedicated constant for the shrinking (same value as before)
3. Add test for querybuf.
4. improve a maxmemory test by ignoring the effect of replica query buffers (can accumulate many ACKs on slow env)
5. improve a maxmemory by disabling slowlog (it will cause slight memory growth on slow env).
Today when we load the AOF on startup, the loadAppendOnlyFile checks if
the file is openning for reading.
This check is redundent (dead code) as we open the AOF file for writing at initServer,
and the file will always be existing for the loadAppendOnlyFile.
In this commit:
- remove all the exit(1) from loadAppendOnlyFile, as it is the caller
responsibility to decide what to do in case of failure.
- move the opening of the AOF file for writing, to be after we loading it.
- avoid return -ERR in DEBUG LOADAOF, when the AOF is existing but empty
This PR adds a spell checker CI action that will fail future PRs if they introduce typos and spelling mistakes.
This spell checker is based on blacklist of common spelling mistakes, so it will not catch everything,
but at least it is also unlikely to cause false positives.
Besides that, the PR also fixes many spelling mistakes and types, not all are a result of the spell checker we use.
Here's a summary of other changes:
1. Scanned the entire source code and fixes all sorts of typos and spelling mistakes (including missing or extra spaces).
2. Outdated function / variable / argument names in comments
3. Fix outdated keyspace masks error log when we check `config.notify-keyspace-events` in loadServerConfigFromString.
4. Trim the white space at the end of line in `module.c`. Check: https://github.com/redis/redis/pull/7751
5. Some outdated https link URLs.
6. Fix some outdated comment. Such as:
- In README: about the rdb, we used to said create a `thread`, change to `process`
- dbRandomKey function coment (about the dictGetRandomKey, change to dictGetFairRandomKey)
- notifyKeyspaceEvent fucntion comment (add type arg)
- Some others minor fix in comment (Most of them are incorrectly quoted by variable names)
7. Modified the error log so that users can easily distinguish between TCP and TLS in `changeBindAddr`
Till now, on replica full-sync we used to transfer absolute time for TTL,
however when a command arrived (EXPIRE or EXPIREAT),
we used to propagate it as is to replicas (possibly with relative time),
but always translate it to EXPIREAT (absolute time) to AOF.
This commit changes that and will always use absolute time for propagation.
see discussion in #8433
Furthermore, we Introduce new commands: `EXPIRETIME/PEXPIRETIME`
that allow extracting the absolute TTL time from a key.
When client breached the output buffer soft limit but then went idle,
we didn't disconnect on soft limit timeout, now we do.
Note this also resolves some sporadic test failures in due to Linux
buffering data which caused tests to fail if during the test we went
back under the soft COB limit.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: sundb <sundbcn@gmail.com>
This solves an issue reported in #8712 in which a replica would bypass
the client write pause check and cause an assertion due to executing a
write command during failover.
The fact is that we don't expect replicas to execute any command other
than maybe REPLCONF and PING, etc. but matching against the ADMIN
command flag is insufficient, so instead i just block keyspace access
for now.
When replica never successfully connect to master, server.repl_down_since
will be initialized to 0, therefore, the info master_link_down_since_seconds
was showing the current unix timestamp, which does not make much sense.
This commit fixes the issue by showing master_link_down_since_seconds to -1.
means the replica never connect to master before.
This commit also resets this variable back to 0 when a replica is turned into
a master, so that it'll behave the same if the master is later turned into a
replica again.
The implication of this change is that if some app is checking if the value is > 60
do something, like conclude the replica is stale, this could case harm (changing
a big positive number with a small one).
The bio aof fsync fd may be closed by main thread (AOFRW done handler)
and even possibly reused for another socket, pipe, or file.
This can can an EBADF or EINVAL fsync error, which will lead to -MISCONF errors failing all writes.
We just ignore these errno because aof fsync did not really fail.
We handle errno when fsyncing aof in bio, so we could know the real reason
when users get -MISCONF Errors writing to the AOF file error
Issue created with #8419
In `aof.c`, we call fsync when stop aof, and now print a log to let user know that if fail.
In `cluster.c`, we now return error, the calling function already handles these write errors.
In `redis-cli.c`, users hope to save rdb, we now print a message if fsync failed.
In `rio.c`, we now treat fsync errors like we do for write errors.
In `server.c`, we try to fsync aof file when shutdown redis, we only can print one log if fail.
In `bio.c`, if failing to fsync aof file, we will set `aof_bio_fsync_status` to error , and reject writing just like last writing aof error, moreover also set INFO command field `aof_last_write_status` to error.
The implications of this change is just that in the past when a config file was missing,
in some cases it was exiting before printing the sever startup prints and sometimes after,
and now it'll always exit before printing them.
The 'sentinel replicas <master>' command will ignore replicas with
`replica-announced` set to no.
The goal of disabling the config setting replica-announced is to allow ghost
replicas. The replica is in the cluster, synchronize with its master, can be
promoted to master and is not exposed to sentinel clients. This way, it is
acting as a live backup or living ghost.
In addition, to prevent the replica to be promoted as master, set
replica-priority to 0.
Add publish channel permissions check in processCommand.
processCommand didn't check publish channel permissions, so we can
queue a publish command in a transaction. But when exec the transaction,
it will fail with -NOPERM.
We also union keys/commands/channels permissions check togegher in
ACLCheckAllPerm. Remove pubsubCheckACLPermissionsOrReply in
publishCommand/subscribeCommand/psubscribeCommand. Always
check permissions in processCommand/execCommand/
luaRedisGenericCommand.
* SLOWLOG didn't record anything for blocked commands because the client
was reset and argv was already empty. there was a fix for this issue
specifically for modules, now it works for all blocked clients.
* The original command argv (before being re-written) was also reset
before adding the slowlog on behalf of the blocked command.
* Latency monitor is now updated regardless of the slowlog flags of the
command or its execution (their purpose is to hide sensitive info from
the slowlog, not hide the fact the latency happened).
* Latency monitor now uses real_cmd rather than c->cmd (which may be
different if the command got re-written, e.g. GEOADD)
Changes:
* Unify shared code between slowlog insertion in call() and
updateStatsOnUnblock(), hopefully prevent future bugs from happening
due to the later being overlooked.
* Reset CLIENT_PREVENT_LOGGING in resetClient rather than after command
processing.
* Add a test for SLOWLOG and BLPOP
Notes:
- real_cmd == c->lastcmd, except inside MULTI and Lua.
- blocked commands never happen in these cases (MULTI / Lua)
- real_cmd == c->cmd, except for when the command is rewritten (e.g.
GEOADD)
- blocked commands (currently) are never rewritten
- other than the command's CLIENT_PREVENT_LOGGING, and the
execution flag CLIENT_PREVENT_LOGGING, other cases that we want to
avoid slowlog are on AOF loading (specifically CMD_CALL_SLOWLOG will
be off when executed from execCommand that runs from an AOF)
Reading CoW from /proc/<pid>/smaps can be slow with large processes on
some platforms.
This measures the time it takes to read CoW info and limits the duty
cycle of future updates to roughly 1/100.
As current_cow_size no longer represnets a current, fixed interval value
there is also a new current_cow_size_age field that provides information
about the age of the size value, in seconds.
In certain scenario start_server may think it failed to start a redis server
although it started successfully. in these cases, it'll not terminate it, and
it'll remain running when the test is over.
In start_server if config doesn't have bind (the minimal.conf in introspection.tcl),
it will try to bind ipv4 and ipv6. One may success while other fails. It will
output "Could not create server TCP listening socket".
wait_server_started uses this message to check whether instance started
successfully. So it will consider that it failed even though redis started successfully.
Additionally, in some cases it wasn't clear to users why the server exited,
since the warning message printed to the log, could in some cases be harmless,
and in some cases fatal.
This PR adds makes a clear distinction between a warning log message and
a fatal one, and changes the test suite to look for the fatal message.
listenToPort attempts to gracefully handle and ignore certain errors but does not store errno prior to logging, which in turn calls several libc functions that may overwrite errno.
This has been discovered due to libmusl strftime() always returning with errno set to EINVAL, which resulted with docker-library/redis#273.
1. moduleReplicateMultiIfNeeded should use server.in_eval like
moduleHandlePropagationAfterCommandCallback
2. server.in_eval could have been set to 1 and not reset back
to 0 (a lot of missed early-exits after in_eval is already 1)
Note: The new assertions in processCommand cover (2) and I added
two module tests to cover (1)
Implications:
If an EVAL that failed (and thus left server.in_eval=1) runs before a module
command that replicates, the replication stream will contain MULTI (because
moduleReplicateMultiIfNeeded used to check server.lua_caller which is NULL
at this point) but not EXEC (because server.in_eval==1)
This only affects modules as module.c the only user of server.in_eval.
Affects versions 6.2.0, 6.2.1
On a replica we do accept connections, even though commands accessing
the database will operate in read-only mode. But the server is still
already operational and processing commands.
Not sending the readiness notification means that on a HA setup where
the nodes all start as replicas (with replicaof in the config) with
a replica that cannot connect to the master server and which might not
come back in a predictable amount of time or at all, the service
supervisor will end up timing out the service and terminating it, with
no option to promote it to be the main instance. This seems counter to
what the readiness notification is supposed to be signaling.
Instead send the readiness notification when we start accepting
commands, and then send the various server status changes as that.
Fixes: commit 641c64ada1
Fixes: commit dfb598cf33
Bug 1:
When a module ctx is freed moduleHandlePropagationAfterCommandCallback
is called and handles propagation. We want to prevent it from propagating
commands that were not replicated by the same context. Example:
1. module1.foo does: RM_Replicate(cmd1); RM_Call(cmd2); RM_Replicate(cmd3)
2. RM_Replicate(cmd1) propagates MULTI and adds cmd1 to also_propagagte
3. RM_Call(cmd2) create a new ctx, calls call() and destroys the ctx.
4. moduleHandlePropagationAfterCommandCallback is called, calling
alsoPropagates EXEC (Note: EXEC is still not written to socket),
setting server.in_trnsaction = 0
5. RM_Replicate(cmd3) is called, propagagting yet another MULTI (now
we have nested MULTI calls, which is no good) and then cmd3
We must prevent RM_Call(cmd2) from resetting server.in_transaction.
REDISMODULE_CTX_MULTI_EMITTED was revived for that purpose.
Bug 2:
Fix issues with nested RM_Call where some have '!' and some don't.
Example:
1. module1.foo does RM_Call of module2.bar without replication (i.e. no '!')
2. module2.bar internally calls RM_Call of INCR with '!'
3. at the end of module1.foo we call RM_ReplicateVerbatim
We want the replica/AOF to see only module1.foo and not the INCR from module2.bar
Introduced a global replication_allowed flag inside RM_Call to determine
whether we need to replicate or not (even if '!' was specified)
Other changes:
Split beforePropagateMultiOrExec to beforePropagateMulti afterPropagateExec
just for better readability
`master_sync_perc` and `loading_loaded_perc` don't have that sign,
and i think the info field should be a raw floating point number (the name suggests its units).
we already have `used_memory_peak_perc` and `used_memory_dataset_perc` which do add the `%` sign, but:
1) i think it was a mistake but maybe too late to fix now, and maybe not too late to fix for `current_fork_perc`
2) it is more important to be consistent with the two other "progress" "prec" metrics, and not with the "utilization" metric.
1. Add `redis-server test all` support to run all tests.
2. Add redis test to daily ci.
3. Add `--accurate` option to run slow tests for more iterations (so that
by default we run less cycles (shorter time, and less prints).
4. Move dict benchmark to REDIS_TEST.
5. fix some leaks in tests
6. make quicklist tests run on a specific fill set of options rather than huge ranges
7. move some prints in quicklist test outside their loops to reduce prints
8. removing sds.h from dict.c since it is now used in both redis-server and
redis-cli (uses hiredis sds)
When no connected clients variables stopped being updated instead of being zeroed over time.
The other changes are cleanup and optimization (avoiding an unnecessary division per client)
Add ability to modify port, tls-port and bind configurations by CONFIG SET command.
To simplify the code and make it cleaner, a new structure
added, socketFds, which contains the file descriptors array and its counter,
and used for TCP, TLS and Cluster sockets file descriptors.
Originally this was limited to IPv6 address length, but effectively it
has been used for host names and now that Sentinel accepts that as well
we need to be able to store full hostnames.
Fixes#8507
* Adding current_save_keys_total and current_save_keys_processed info fields.
Present in replication, BGSAVE and AOFRW.
* Changing RM_SendChildCOWInfo() to RM_SendChildHeartbeat(double progress)
* Adding new info field current_fork_perc. Present in Replication, BGSAVE, AOFRW,
and module forks.
This commit enables tracking time of the background tasks and on replies,
opening the door for properly tracking commands that rely on blocking / background
work via the slowlog, latency history, and commandstats.
Some notes:
- The time spent blocked waiting for key changes, or blocked on synchronous
replication is not accounted for.
- **This commit does not affect latency tracking of commands that are non-blocking
or do not have background work.** ( meaning that it all stays the same with exception to
`BZPOPMIN`,`BZPOPMAX`,`BRPOP`,`BLPOP`, etc... and module's commands that rely
on background threads ).
- Specifically for latency history command we've added a new event class named
`command-unblocking` that will enable latency monitoring on commands that spawn
background threads to do the work.
- For blocking commands we're now considering the total time of a command as the
time spent on call() + the time spent on replying when unblocked.
- For Modules commands that rely on background threads we're now considering the
total time of a command as the time spent on call (main thread) + the time spent on
the background thread ( if marked within `RedisModule_MeasureTimeStart()` and
`RedisModule_MeasureTimeEnd()` ) + the time spent on replying (main thread)
To test for this feature we've added a `unit/moduleapi/blockonbackground` test that relies on
a module that blocks the client and sleeps on the background for a given time.
- check blocked command that uses RedisModule_MeasureTimeStart() is tracking background time
- check blocked command that uses RedisModule_MeasureTimeStart() is tracking background time even in timeout
- check blocked command with multiple calls RedisModule_MeasureTimeStart() is tracking the total background time
- check blocked command without calling RedisModule_MeasureTimeStart() is not reporting background time
New commands:
`HRANDFIELD [<count> [WITHVALUES]]`
`ZRANDMEMBER [<count> [WITHSCORES]]`
Algorithms are similar to the one in SRANDMEMBER.
Both return a simple bulk response when no arguments are given, and an array otherwise.
In case values/scores are requested, RESP2 returns a long array, and RESP3 a nested array.
note: in all 3 commands, the only option that also provides random order is the one with negative count.
Changes to SRANDMEMBER
* Optimization when count is 1, we can use the more efficient algorithm of non-unique random
* optimization: work with sds strings rather than robj
Other changes:
* zzlGetScore: when zset needs to convert string to double, we use safer memcpy (in
case the buffer is too small)
* Solve a "bug" in SRANDMEMBER test: it intended to test a positive count (case 3 or
case 4) and by accident used a negative count
Co-authored-by: xinluton <xinluton@qq.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
The key point is how to recover from last AOF write error, for example:
1. start redis with appendonly yes, and append some write commands
2. short write or something else error happen, `server.aof_last_write_status` changed to `C_ERR`, now redis doesn't accept write commands
3. execute `CONFIG SET appendonly no` to avoid the above problem, now redis can accept write commands again
4. disk error resolved, and execute `CONFIG SET appendonly yes` to reopen AOF, but `server.aof_last_write_status` cannot be changed to `C_OK` (if background aof rewrite run less then 1 second, it will free `server.aof_buf` and then serverCron cannot fix `aof_last_write_status`), then redis cannot accept write commands forever.
This PR use a simple way to fix it:
1. just free `server.aof_buf` when stop appendonly to save memory, if error happens in `flushAppendOnlyFile(1)`, the `server.aof_buf` may contains some data which has not be written to aof, I think we can ignore it because we turn off the appendonly.
2. reset fsync status after stop appendonly and call `flushAppendOnlyFile` only when `aof_state` is ON
3. reset `server.last_write_status` when reopen aof to accept write commands
if option `set-proc-title' is no, then do nothing for proc title.
The reason has been explained long ago, see following:
We update redis to 2.8.8, then found there are some side effect when
redis always change the process title.
We run several slave instance on one computer, and all these salves
listen on unix socket only, then ps will show:
1 S redis 18036 1 0 80 0 - 56130 ep_pol 14:02 ? 00:00:31 /usr/sbin/redis-server *:0
1 S redis 23949 1 0 80 0 - 11074 ep_pol 15:41 ? 00:00:00 /usr/sbin/redis-server *:0
for redis 2.6 the output of ps is like following:
1 S redis 18036 1 0 80 0 - 56130 ep_pol 14:02 ? 00:00:31 /usr/sbin/redis-server /etc/redis/a.conf
1 S redis 23949 1 0 80 0 - 11074 ep_pol 15:41 ? 00:00:00 /usr/sbin/redis-server /etc/redis/b.conf
Later is more informational in our case. The situation
is worse when we manage the config and process running
state by salt. Salt check the process by running "ps |
grep SIG" (for Gentoo System) to check the running
state, where SIG is the string to search for when
looking for the service process with ps. Previously, we
define sig as "/usr/sbin/redis-server
/etc/redis/a.conf". Since the ps output is identical for
our case, so we have no way to check the state of
specified redis instance.
So, for our case, we prefer the old behavior, i.e, do
not change the process title for the main redis process.
Or add an option such as "set-proc-title [yes|no]" to
control this behavior.
Co-authored-by: Yossi Gottlieb <yossigo@gmail.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
At least in one case the arm64 cow kernel bug test triggers an assert, which is a problem because it cannot be ignored like cases where the bug is found.
On older systems (Linux <4.5) madvise fails because MADV_FREE is not supported. We treat these failures as an indication the system is not affected.
Fixes#8351, #8406
This commit introduces two new command and two options for an existing command
GETEX <key> [PERSIST][EX seconds][PX milliseconds] [EXAT seconds-timestamp]
[PXAT milliseconds-timestamp]
The getexCommand() function implements extended options and variants of the GET
command. Unlike GET command this command is not read-only. Only one of the options
can be used at a given time.
1. PERSIST removes any TTL associated with the key.
2. EX Set expiry TTL in seconds.
3. PX Set expiry TTL in milliseconds.
4. EXAT Same like EX instead of specifying the number of seconds representing the
TTL (time to live), it takes an absolute Unix timestamp
5. PXAT Same like PX instead of specifying the number of milliseconds representing the
TTL (time to live), it takes an absolute Unix timestamp
Command would return either the bulk string, error or nil.
GETDEL <key>
Would delete the key after getting.
SET key value [NX] [XX] [KEEPTTL] [GET] [EX <seconds>] [PX <milliseconds>]
[EXAT <seconds-timestamp>][PXAT <milliseconds-timestamp>]
Two new options added here are EXAT and PXAT
Key implementation notes
- `SET` with `PX/EX/EXAT/PXAT` is always translated to `PXAT` in `AOF`. When relative time is
specified (`PX/EX`), replication will always use `PX`.
- `setexCommand` and `psetexCommand` would no longer need translation in `feedAppendOnlyFile`
as they are modified to invoke `setGenericCommand ` with appropriate flags which will take care of
correct AOF translation.
- `GETEX` without any optional argument behaves like `GET`.
- `GETEX` command is never propagated, It is either propagated as `PEXPIRE[AT], or PERSIST`.
- `GETDEL` command is propagated as `DEL`
- Combined the validation for `SET` and `GETEX` arguments.
- Test cases to validate AOF/Replication propagation
This commit fixes a well known and an annoying issue in Sentinel mode.
Cause of this issue:
Currently, Redis rewrite process works well in server mode, however in sentinel mode,
the sentinel config has variant semantics for different configurations, in example configuration
https://github.com/redis/redis/blob/unstable/sentinel.conf, we put comments on these.
However the rewrite process only treat the sentinel config as a single option. During rewrite
process, it will mess up with the lines and comments.
Approaches:
In order to solve this issue, we need to differentiate different subconfig options in sentinel separately,
for example, sentinel monitor <master-name> <ip> <redis-port> <quorum>
we can treat it as sentinel monitor option, instead of the sentinel option.
This commit also fixes the dependency issue when putting configurations in sentinel.conf.
For example before this commit,we must put
`sentinel monitor <master-name> <ip> <redis-port> <quorum>` before
`sentinel auth-pass <master-name> <password>` for a single master,
otherwise the server cannot start and will return error. This commit fixes this issue, as long as
the monitoring master was configured, no matter the sequence is, the sentinel can start and run properly.
Fixes a regression introduced due to a new (safer) way of rewriting configuration files. In the past the file was simply overwritten (same inode), but now Redis creates a new temporary file and later renames it over the old one.
The temp file typically gets created with 0600 permissions so we later fchmod it to fix that. Unlike open with O_CREAT, fchmod doesn't consider umask so we have to do that explicitly.
Fixes#8369
The output for COMMAND command was wrong for some commands.
clients can use firstkey,lastkey,step to find (some) key name arguments, and the
"movablekeys" flag to know that they can't know all (or any) of the key name arguments.
These commands had the wrong output:
1. GEORADIUS*_RO used to have "movablekeys" (which it doesn't really need)
2. XREAD and XREADGROUP used to have (1,1,1). but that's completely wrong.
3. Z*STORE used to have (0,0,0) but it can at lest give the index of the dstkey (1,1,1)
Sentinel uses execve to run scripts, so it needs to use FD_CLOEXEC
on all file descriptors, so that they're not accessible by the script it runs.
This commit includes a change to the sentinel tests, which verifies no
FDs are left opened when the script is executed.
This fixes three issues:
1. Using debug SLEEP was impacting the subsequent test, and causing it to pass reliably even though it should have failed. There was exactly 5 seconds of artificial pause (after 1000, wait 3000, wait 1000) between the debug sleep 5 and when we needed to unblock the client in the subsequent test. Now the test properly makes sure the client is unblocked, and the subsequent test is fixed.
2. Minor, the client pause types were using & comparisons instead of ==, since it was previously a flag.
3. Test is faster now that some of the hand wavy time is removed.
Older arm64 Linux kernels have a bug that could lead to data corruption during
background save under the following scenario:
1) jemalloc uses MADV_FREE on a page,
2) jemalloc reuses and writes the page,
3) Redis forks the background save process, and
4) Linux performs page reclamation.
Under these conditions, Linux will reclaim the page wrongfully and the
background save process will read zeros when it tries to read the page.
The bug has been fixed in Linux with commit:
ff1712f953e27f0b0718762ec17d0adb15c9fd0b ("arm64: pgtable: Ensure dirty bit is
preserved across pte_wrprotect()")
This Commit adds an ignore-warnings config, when not found, redis will
print a warning and exit on startup (default behavior).
Co-authored-by: Oran Agra <oran@redislabs.com>
Add INFO field, rdb_active_cow_size, to report COW of a live fork child while
it's active.
- once in 1024 keys check the time, and if there's more than one second since
the last report send a report to the parent via the pipe.
- refactor the child_info_data struct, it's an implementation detail that
shouldn't be in the server struct, and not used to communicate data between
caller and callee
- remove the magic value from that struct (not sure what it was good for), and
instead add handling of short reads.
- add another value to the structure, cow_type, to indicate if the report is
for the new rdb_active_cow_size field, or it's the last report of a
successful operation
- add new Module API to report the active COW
- add more asserts variants to test.tcl
This is a refactory commit, isn't suppose to have any actual impact.
it does the following:
- keep just one server struct fork child pid variable instead of 3
- have one server struct variable indicating the purpose of the current fork
child.
- redisFork is now responsible of updating the server struct with the pid,
which means it can be the one that calls updateDictResizePolicy
- move child info pipe handling into redisFork instead of having them
repeated outside
- there are two classes of fork purposes, mutually exclusive group (AOF, RDB,
Module), and one that can create several forks to coexist in parallel (LDB,
but maybe Modules some day too, Module API allows for that).
- minor fix to killRDBChild:
unlike killAppendOnlyChild and TerminateModuleForkChild, the killRDBChild
doesn't clear the pid variable or call wait4, so checkChildrenDone does
the cleanup for it.
This commit removes the explicit calls to rdbRemoveTempFile, closeChildInfoPipe,
updateDictResizePolicy, which didn't do any harm, but where unnecessary.
Add ZRANGESTORE command, and improve ZSTORE command to deprecated Z[REV]RANGE[BYSCORE|BYLEX].
Syntax for the new ZRANGESTORE command:
ZRANGESTORE [BYSCORE | BYLEX] [REV] [LIMIT offset count]
New syntax for ZRANGE:
ZRANGE [BYSCORE | BYLEX] [REV] [WITHSCORES] [LIMIT offset count]
Old syntax for ZRANGE:
ZRANGE [WITHSCORES]
Other ZRANGE commands remain unchanged.
The implementation uses common code for all of these, by utilizing a consumer interface that in one
command response to the client, and in the other command stores a zset key.
Co-authored-by: Oran Agra <oran@redislabs.com>
New command: XAUTOCLAIM <key> <group> <consumer> <min-idle-time> <start> [COUNT <count>] [JUSTID]
The purpose is to claim entries from a stale consumer without the usual
XPENDING+XCLAIM combo which takes two round trips.
The syntax for XAUTOCLAIM is similar to scan: A cursor is returned (streamID)
by each call and should be used as start for the next call. 0-0 means the scan is complete.
This PR extends the deferred reply mechanism for any bulk string (not just counts)
This PR carries some unrelated test code changes:
- Renames the term "client" into "consumer" in the stream-cgroups test
- And also changes DEBUG SLEEP into "after"
Co-authored-by: Oran Agra <oran@redislabs.com>
* man-like consistent long formatting
* Uppercases commands, subcommands and options
* Adds 'HELP' to HELP for all
* Lexicographical order
* Uses value notation and other .md likeness
* Moves const char *help to top
* Keeps it under 80 chars
* Misc help typos, consistent conjuctioning (i.e return and not returns)
* Uses addReplySubcommandSyntaxError(c) all over
Signed-off-by: Itamar Haber <itamar@redislabs.com>
If AOF file contains a long Lua script that timed out, then the `evalCommand` calls
`blockingOperationEnds` which sets `server.blocked_last_cron` to 0. later on,
the AOF `whileBlockedCron` function asserts that this value is not 0.
The fix allows nesting call to `blockingOperationStarts` and `blockingOperationEnds`.
The issue was first introduce in this commit: 9ef8d2f67 (Redis 6.2 RC1)
In #7726 (part of 6.2), we added a mechanism for whileBlockedCron, this
mechanism has an assertion to make sure the timestamp in
whileBlockedCron was always set correctly before the blocking operation
starts.
I now found (thanks to our CI) two bugs in that area:
1) CONFIG RESETSTAT (if it was allowed during loading) would have
cleared this var
2) the call stopLoading (which calls whileBlockedCron) was made too
early, while the rio is still in use, in which case the update_cksum
(rdbLoadProgressCallback) may still be called and whileBlockedCron
can assert.
This Commit pushes forward the observability on overall error statistics and command statistics within redis-server:
It extends INFO COMMANDSTATS to have
- failed_calls in - so we can keep track of errors that happen from the command itself, broken by command.
- rejected_calls - so we can keep track of errors that were triggered outside the commmand processing per se
Adds a new section to INFO, named ERRORSTATS that enables keeping track of the different errors that
occur within redis ( within processCommand and call ) based on the reply Error Prefix ( The first word
after the "-", up to the first space ).
This commit also fixes RM_ReplyWithError so that it can be correctly identified as an error reply.
Recently efaf09ee4 started using addReplyErrorSds in place of
addReplySds the later takes ownership of the string but the former did
not.
This introduced memory leaks when a script returns an error to redis,
and also in clusterRedirectClient (two new usages of
addReplyErrorSds which was mostly unused till now.
This commit chagnes two thanks.
1. change addReplyErrorSds to take ownership of the error string.
2. scripting.c doesn't actually need to use addReplyErrorSds, it's a
perfect match for addReplyErrorFormat (replaces newlines with spaces)
Adds: `L/RPOP <key> [count]`
Implements no. 2 of the following strategies:
1. Loop on listTypePop - this would result in multiple calls for memory freeing and allocating (see 769167a079)
2. Iterate the range to build the reply, then call quickListDelRange - this requires two iterations and **is the current choice**
3. Refactor quicklist to have a pop variant of quickListDelRange - probably optimal but more complex
Also:
* There's a historical check for NULL after calling listTypePop that was converted to an assert.
* This refactors common logic shared between LRANGE and the new form of LPOP/RPOP into addListRangeReply (adds test for b/w compat)
* Consequently, it may have made sense to have `LRANGE l -1 -2` and `LRANGE l 9 0` be legit and return a reverse reply. Due to historical reasons that would be, however, a breaking change.
* Added minimal comments to existing commands to adhere to the style, make core dev life easier and get commit karma, naturally.
When a database on a 64 bit build grows past 2^31 keys, the underlying hash table expands to 2^32 buckets. After this point, the algorithms for selecting random elements only return elements from half of the available buckets because they use random() which has a range of 0 to 2^31 - 1. This causes problems for eviction policies which use dictGetSomeKeys or dictGetRandomKey. Over time they cause the hash table to become unbalanced because, while new keys are spread out evenly across all buckets, evictions come from only half of the available buckets. Eventually this half of the table starts to run out of keys and it takes longer and longer to find candidates for eviction. This continues until no more evictions can happen.
This solution addresses this by using a 64 bit PRNG instead of libc random().
Co-authored-by: Greg Femec <gfemec@google.com>
Turns out that when the fork child crashes, the crash log was deleting
the pidfile from the disk (although the parent is still running.
Now we set the pidfile of the fork process to NULL so the fork process
will never deletes it.
In the distant history there was only the read flag for commands, and whatever
command that didn't have the read flag was a write one.
Then we added the write flag, but some portions of the code still used !read
Also some commands that don't work on the keyspace at all, still have the read
flag.
Changes in this commit:
1. remove the read-only flag from TIME, ECHO, ROLE and LASTSAVE
2. EXEC command used to decides if it should propagate a MULTI by looking at
the command flags (!read & !admin).
When i was about to change it to look at the write flag instead, i realized
that this would cause it not to propagate a MULTI for PUBLISH, EVAL, and
SCRIPT, all 3 are not marked as either a read command or a write one (as
they should), but all 3 are calling forceCommandPropagation.
So instead of introducing a new flag to denote a command that "writes" but
not into the keyspace, and still needs propagation, i decided to rely on
the forceCommandPropagation, and just fix the code to propagate MULTI when
needed rather than depending on the command flags at all.
The implication of my change then is that now it won't decide to propagate
MULTI when it sees one of these: SELECT, PING, INFO, COMMAND, TIME and
other commands which are neither read nor write.
3. Changing getNodeByQuery and clusterRedirectBlockedClientIfNeeded in
cluster.c to look at !write rather than read flag.
This should have no implications, since these code paths are only reachable
for commands which access keys, and these are always marked as either read
or write.
This commit improve MULTI propagation tests, for modules and a bunch of
other special cases, all of which used to pass already before that commit.
the only one that test change that uncovered a change of behavior is the
one that DELs a non-existing key, it used to propagate an empty
multi-exec block, and no longer does.
Exposes the main thread CPU info via info modules ( linux specific only )
(used_cpu_sys_main_thread and used_cpu_user_main_thread). This is important for:
- distinguish between main thread and io-threads cpu time total cpu time consumed ( check
what is the first bottleneck on the used config )
- distinguish between main thread and modules threads total cpu time consumed
Apart from it, this commit also exposes the server_time_usec within the Server section so that we can
properly differentiate consecutive collection and calculate for example the CPU% and or / cpu time vs
wall time, etc...
Add commands to query geospatial data with bounding box.
Two new commands that replace the existing 4 GEORADIUS* commands.
GEOSEARCH key [FROMMEMBER member] [FROMLOC long lat] [BYRADIUS radius
unit] [BYBOX width height unit] [WITHCORD] [WITHDIST] [WITHASH] [COUNT
count] [ASC|DESC]
GEOSEARCHSTORE dest_key src_key [FROMMEMBER member] [FROMLOC long lat]
[BYRADIUS radius unit] [BYBOX width height unit] [WITHCORD] [WITHDIST]
[WITHASH] [COUNT count] [ASC|DESC] [STOREDIST]
- Add two types of CIRCULAR_TYPE and RECTANGLE_TYPE to achieve different searches
- Judge whether the point is within the rectangle, refer to:
geohashGetDistanceIfInRectangle
The test creates keys with various encodings, DUMP them, corrupt the payload
and RESTORES it.
It utilizes the recently added use-exit-on-panic config to distinguish between
asserts and segfaults.
If the restore succeeds, it runs random commands on the key to attempt to
trigger a crash.
It runs in two modes, one with deep sanitation enabled and one without.
In the first one we don't expect any assertions or segfaults, in the second one
we expect assertions, but no segfaults.
We also check for leaks and invalid reads using valgrind, and if we find them
we print the commands that lead to that issue.
Changes in the code (other than the test):
- Replace a few NPD (null pointer deference) flows and division by zero with an
assertion, so that it doesn't fail the test. (since we set the server to use
`exit` rather than `abort` on assertion).
- Fix quite a lot of flows in rdb.c that could have lead to memory leaks in
RESTORE command (since it now responds with an error rather than panic)
- Add a DEBUG flag for SET-SKIP-CHECKSUM-VALIDATION so that the test don't need
to bother with faking a valid checksum
- Remove a pile of code in serverLogObjectDebugInfo which is actually unsafe to
run in the crash report (see comments in the code)
- fix a missing boundary check in lzf_decompress
test suite infra improvements:
- be able to run valgrind checks before the process terminates
- rotate log files when restarting servers
When loading an encoded payload we will at least do a shallow validation to
check that the size that's encoded in the payload matches the size of the
allocation.
This let's us later use this encoded size to make sure the various offsets
inside encoded payload don't reach outside the allocation, if they do, we'll
assert/panic, but at least we won't segfault or smear memory.
We can also do 'deep' validation which runs on all the records of the encoded
payload and validates that they don't contain invalid offsets. This lets us
detect corruptions early and reject a RESTORE command rather than accepting
it and asserting (crashing) later when accessing that payload via some command.
configuration:
- adding ACL flag skip-sanitize-payload
- adding config sanitize-dump-payload [yes/no/clients]
For now, we don't have a good way to ensure MIGRATE in cluster resharding isn't
being slowed down by these sanitation, so i'm setting the default value to `no`,
but later on it should be set to `clients` by default.
changes:
- changing rdbReportError not to `exit` in RESTORE command
- adding a new stat to be able to later check if cluster MIGRATE isn't being
slowed down by sanitation.
One way this was happening is when a module issued an RM_Call which would inject MULTI.
If the module command that does that was itself issued by something else that already did
added MULTI (e.g. another module, or a Lua script), it would have caused nested MULTI.
In fact the MULTI state in the client or the MULTI_EMITTED flag in the context isn't
the right indication that we need to propagate MULTI or not, because on a nested calls
(possibly a module action called by a keyspace event of another module action), these
flags aren't retained / reflected.
instead there's now a global propagate_in_transaction flag for that.
in addition to that, we now have a global in_eval and in_exec flags, to serve the flags
of RM_GetContextFlags, since their dependence on the current client is wrong for the same
reasons mentioned above.
As we know, redis may reject user's requests or evict some keys if
used memory is over maxmemory. Dictionaries expanding may make
things worse, some big dictionaries, such as main db and expires dict,
may eat huge memory at once for allocating a new big hash table and be
far more than maxmemory after expanding.
There are related issues: #4213#4583
More details, when expand dict in redis, we will allocate a new big
ht[1] that generally is double of ht[0], The size of ht[1] will be
very big if ht[0] already is big. For db dict, if we have more than
64 million keys, we need to cost 1GB for ht[1] when dict expands.
If the sum of used memory and new hash table of dict needed exceeds
maxmemory, we shouldn't allow the dict to expand. Because, if we
enable keys eviction, we still couldn't add much more keys after
eviction and rehashing, what's worse, redis will keep less keys when
redis only remains a little memory for storing new hash table instead
of users' data. Moreover users can't write data in redis if disable
keys eviction.
What this commit changed ?
Add a new member function expandAllowed for dict type, it provide a way
for caller to allow expand or not. We expose two parameters for this
function: more memory needed for expanding and dict current load factor,
users can implement a function to make a decision by them.
For main db dict and expires dict type, these dictionaries may be very
big and cost huge memory for expanding, so we implement a judgement
function: we can stop dict to expand provisionally if used memory will
be over maxmemory after dict expands, but to guarantee the performance
of redis, we still allow dict to expand if dict load factor exceeds the
safe load factor.
Add test cases to verify we don't allow main db to expand when left
memory is not enough, so that avoid keys eviction.
Other changes:
For new hash table size when expand. Before this commit, the size is
that double used of dict and later _dictNextPower. Actually we aim to
control a dict load factor between 0.5 and 1.0. Now we replace *2 with
+1, since the first check is that used >= size, the outcome of before
will usually be the same as _dictNextPower(used+1). The only case where
it'll differ is when dict_can_resize is false during fork, so that later
the _dictNextPower(used*2) will cause the dict to jump to *4 (i.e.
_dictNextPower(1025*2) will return 4096).
Fix rehash test cases due to changing algorithm of new hash table size
when expand.
Fixes#7923.
This PR appropriates the special `&` symbol (because `@` and `*` are taken),
followed by a literal value or pattern for describing the Pub/Sub patterns that
an ACL user can interact with. It is similar to the existing key patterns
mechanism in function (additive) and implementation (copy-pasta). It also adds
the allchannels and resetchannels ACL keywords, naturally.
The default user is given allchannels permissions, whereas new users get
whatever is defined by the acl-pubsub-default configuration directive. For
backward compatibility in 6.2, the default of this directive is allchannels but
this is likely to be changed to resetchannels in the next major version for
stronger default security settings.
Unless allchannels is set for the user, channel access permissions are checked
as follows :
* Calls to both PUBLISH and SUBSCRIBE will fail unless a pattern matching the
argumentative channel name(s) exists for the user.
* Calls to PSUBSCRIBE will fail unless the pattern(s) provided as an argument
literally exist(s) in the user's list.
Such failures are logged to the ACL log.
Runtime changes to channel permissions for a user with existing subscribing
clients cause said clients to disconnect unless the new permissions permit the
connections to continue. Note, however, that PSUBSCRIBErs' patterns are matched
literally, so given the change bar:* -> b*, pattern subscribers to bar:* will be
disconnected.
Notes/questions:
* UNSUBSCRIBE, PUNSUBSCRIBE and PUBSUB remain unprotected due to lack of reasons
for touching them.
this metric already includes the argv bytes, like what clientsCronTrackClientsMemUsage does, but it's missing the array itself.
p.s. For the purpose of tracking expensive clients we don't need to include the size of the client struct and the static reply buffer in it.
This is hopefully usually harmles.
The server.ready_keys will usually be empty so the code after releasing
the GIL will soon be done.
The only case where it'll actually process things is when a module
releases a client (or module) blocked on a key, by triggering this NOT
from within a command (e.g. a timer event).
This bug was introduced in redis 6.0.9, see #7903
Fix: When oom-score-adj-values is provided in the config file after
oom-score-adj yes, it'll take an immediate action, before
readOOMScoreAdj was acquired, resulting in an error (out of range score
due to uninitialized value. delay the reaction the real call is made by
main().
Since the values are clamped to -1000..1000, and they're
applied as an offset from the value at startup (which may be -1000), we
need to allow the offsets to reach to +2000 so that a value of +1000 is
achievable in case the value at startup was -1000.
Adding an option for absolute values rather than relative ones.
Blocking command should not be used with MULTI, LUA, and RM_Call. This is because,
the caller, who executes the command in this context, expects a reply.
Today, LUA and MULTI have a special (and different) treatment to blocking commands:
LUA - Most commands are marked with no-script flag which are checked when executing
and command from LUA, commands that are not marked (like XREAD) verify that their
blocking mode is not used inside LUA (by checking the CLIENT_LUA client flag).
MULTI - Command that is going to block, first verify that the client is not inside
multi (by checking the CLIENT_MULTI client flag). If the client is inside multi, they
return a result which is a match to the empty key with no timeout (for example blpop
inside MULTI will act as lpop)
For modules that perform RM_Call with blocking command, the returned results type is
REDISMODULE_REPLY_UNKNOWN and the caller can not really know what happened.
Disadvantages of the current state are:
No unified approach, LUA, MULTI, and RM_Call, each has a different treatment
Module can not safely execute blocking command (and get reply or error).
Though It is true that modules are not like LUA or MULTI and should be smarter not
to execute blocking commands on RM_Call, sometimes you want to execute a command base
on client input (for example if you create a module that provides a new scripting
language like javascript or python).
While modules (on modules command) can check for REDISMODULE_CTX_FLAGS_LUA or
REDISMODULE_CTX_FLAGS_MULTI to know not to block the client, there is no way to
check if the command came from another module using RM_Call. So there is no way
for a module to know not to block another module RM_Call execution.
This commit adds a way to unify the treatment for blocking clients by introducing
a new CLIENT_DENY_BLOCKING client flag. On LUA, MULTI, and RM_Call the new flag
turned on to signify that the client should not be blocked. A blocking command
verifies that the flag is turned off before blocking. If a blocking command sees
that the CLIENT_DENY_BLOCKING flag is on, it's not blocking and return results
which are matches to empty key with no timeout (as MULTI does today).
The new flag is checked on the following commands:
List blocking commands: BLPOP, BRPOP, BRPOPLPUSH, BLMOVE,
Zset blocking commands: BZPOPMIN, BZPOPMAX
Stream blocking commands: XREAD, XREADGROUP
SUBSCRIBE, PSUBSCRIBE, MONITOR
In addition, the new flag is turned on inside the AOF client, we do not want to
block the AOF client to prevent deadlocks and commands ordering issues (and there
is also an existing assert in the code that verifies it).
To keep backward compatibility on LUA, all the no-script flags on existing commands
were kept untouched. In addition, a LUA special treatment on XREAD and XREADGROUP was kept.
To keep backward compatibility on MULTI (which today allows SUBSCRIBE, and PSUBSCRIBE).
We added a special treatment on those commands to allow executing them on MULTI.
The only backward compatibility issue that this PR introduces is that now MONITOR
is not allowed inside MULTI.
Tests were added to verify blocking commands are not blocking the client on LUA, MULTI,
or RM_Call. Tests were added to verify the module can check for CLIENT_DENY_BLOCKING flag.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Itamar Haber <itamar@redislabs.com>
* Configuration file default should now be "auto".
* Expose "process_supervised" as an info field.
* Log messages improvements (clarify required systemd config, report
auto-detected supervision mode, etc.)
* Set server.supervised properly, so it can take precedence of
"daemonize" configuration.
* Produce clear warning if systemd is detected/requested but executable
is compiled without support for it, instead of silently ignoring.
* Handle systemd notification error on startup, and turn off supervised
mode if it failed.
Syntax:
COPY <key> <new-key> [DB <dest-db>] [REPLACE]
No support for module keys yet.
Co-authored-by: tmgauss
Co-authored-by: Itamar Haber <itamar@redislabs.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
Add two optional callbacks to the RedisModuleTypeMethods structure, which is `free_effort`
and `unlink`. the `free_effort` callback indicates the effort required to free a module memory.
Currently, if the effort exceeds LAZYFREE_THRESHOLD, the module memory may be released
asynchronously. the `unlink` callback indicates the key has been removed from the DB by redis, and
may soon be freed by a background thread.
Add `lazyfreed_objects` info field, which represents the number of objects that have been
lazyfreed since redis was started.
Add `RM_GetTypeMethodVersion` API, which return the current redis-server runtime value of
`REDISMODULE_TYPE_METHOD_VERSION`. You can use that when calling `RM_CreateDataType` to know
which fields of RedisModuleTypeMethods are gonna be supported and which will be ignored.
- Add ZDIFF and ZDIFFSTORE which work similarly to SDIFF and SDIFFSTORE
- Make sure the new WITHSCORES argument that was added for ZUNION isn't considered valid for ZUNIONSTORE
Co-authored-by: Oran Agra <oran@redislabs.com>
Expose new `loading_rdb_used_mem` showing the used memory of the server
that saved the RDB file we're currently using.
This is useful in diskless replication when the total size of the rdb is
unkown, and can be used as a rought estimation of progres.
Use that new field to calculate the "user friendly"
`loading_loaded_perc` and `loading_eta_seconds`.
Expose `master_sync_total_bytes` and `master_sync_total_bytes` to complement
on the existing `master_sync_total_bytes` (which cannot be used on its own
to calculate progress).
Add "user friendly" field for `master_sync_perc`
Perform full reset of all client connection states, is if the client was
disconnected and re-connected. This affects:
* MULTI state
* Watched keys
* MONITOR mode
* Pub/Sub subscription
* ACL/Authenticated state
* Client tracking state
* Cluster read-only/asking state
* RESP version (reset to 2)
* Selected database
* CLIENT REPLY state
The response is +RESET to make it easily distinguishable from other
responses.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Itamar Haber <itamar@redislabs.com>
Few config settings are also reflected by the INFO command.
these are mainly ones that are important for either an instant view of
the server status (to compare a metric to it's limit config),
Important configurations that are necessary in the crash log (which
currently doesn't print the config),
And things that are important for monitoring solutions (such as
Prometheus), which rely on INFO to collect their data.
Add cluster_connections to INFO CLUSTER:
This makes it possible to be combined together with connected_clients
and connected_slaves and be matched against maxclients
In redisFork(), we don't set child pid, so updateDictResizePolicy()
doesn't take effect, that isn't friendly for copy-on-write.
The bug was introduced this in redis 6.0: 56258c6
The reason that we want to get a full crash report on SIGABRT
is that the jmalloc, when detecting a corruption, calls abort().
This will cause the Redis to exist silently without any report
and without any way to analyze what happened.
Background:
#3467 (redis 4.0.0), started ignoring ENOPROTOOPT, but did that only for
the default bind (in case bind config wasn't explicitly set).
#5598 (redis 5.0.3), added that for bind addresses explicitly set
(following bug reports in Debian for redis 4.0.9 and 5.0.1), it
also ignored a bunch of other errors like EPROTONOSUPPORT which was
requested in #3894, and also added EADDRNOTAVAIL (wasn't clear why).
This (ignoring EADDRNOTAVAIL) makes redis start successfully, even if a
certain network interface isn't up yet , in which case we rather redis
fail and will be re-tried when the NIC is up, see #7933.
However, it turns out that when IPv6 is disabled (supported but unused),
the error we're getting is EADDRNOTAVAIL. and in many systems the
default config file tries to bind to localhost for both v4 and v6 and
would like to silently ignore the error on v6 if disabled.
This means that we sometimes want to ignore EADDRNOTAVAIL and other times
we wanna fail.
So this commit changes these main things:
1. Ignore all the errors we ignore for both explicitly requested bind
address and a default implicit one.
2. Add a '-' prefix to allow EADDRNOTAVAIL be ignored (by default that's
different than the previous behavior).
3. Restructure that function in a more readable and maintainable way see
below.
4. Make the default behavior of listening to all achievable by setting
a bind config directive to * (previously only possible by omitting
it)
5. document everything.
The old structure of this function was that even if there are no bind
addresses requested, the loop that runs though the bind addresses runs
at least once anyway!
In that one iteration of the loop it binds to both v4 and v6 addresses,
handles errors for each of them separately, and then eventually at the
if-else chain, handles the error of the last bind attempt again!
This was very hard to read and very error prone to maintain, instead now
when the bind info is missing we create one with two entries, and run
the simple loop twice.
In case redis starts and find that THP is enabled ("always"), instead
of printing a log message, which might go unnoticed, redis will try to
disable it (just for the redis process).
Note: it looks like on self-bulit kernels THP is likely be set to "always" by default.
Some discuss about THP side effect on Linux:
according to http://www.antirez.com/news/84, we can see that
redis latency spikes are caused by linux kernel THP feature.
I have tested on E3-2650 v3, and found that 2M huge page costs
about 0.25ms to fix COW page fault.
Add a new config 'disable-thp', the recommended setting is 'yes',
(default) the redis tries to disable THP by prctl syscall. But
users who really want THP can set it to "no"
Thanks to Oran & Yossi for suggestions.
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
This commit implements ACL for Sentinel mode, main work of this PR includes:
- Update Sentinel command table in order to better support ACLs.
- Fix couple of things which currently blocks the support for ACL on sentinel mode.
- Provide "sentinel sentinel-user" and "sentinel sentinel-pass " configuration in order to let sentinel authenticate with a specific user in other sentinels.
- requirepass is kept just for compatibility with old config files
Co-authored-by: Oran Agra <oran@redislabs.com>
In some cases one command added a very big bulk of memory, and this
would be "resolved" by the eviction before the next command.
Seeing an unexplained mass eviction we would wish to
know the highest momentary usage too.
Tracking it in call() and beforeSleep() adds some hooks in AOF and RDB
loading.
The fix in clientsCronTrackExpansiveClients is related to #7874
- Clarify some documentation comments
- Make sure blocked-on-keys client privdata is accessible
from withing the timeout callback
- Handle blocked clients in beforeSleep - In case a key
becomes "ready" outside of processCommand
See #7879#7880
Avoid using a static buffer for short key index responses, and make it
caller's responsibility to stack-allocate a result type. Responses that
don't fit are still allocated on the heap.
This allows supplying secret configuration (for example - masterauth) via a secure channel
instead of having it in a plaintext file / command line param, while still allowing for most
of the configuration to reside there.
Also, remove 'special' case handling for --check-rdb which hasn't been relevant
since 4.0.0.
Adding [B]LMOVE <src> <dst> RIGHT|LEFT RIGHT|LEFT. deprecating [B]RPOPLPUSH.
Note that when receiving a BRPOPLPUSH we'll still propagate an RPOPLPUSH,
but on BLMOVE RIGHT LEFT we'll propagate an LMOVE
improvement to existing tests
- Replace "after 1000" with "wait_for_condition" when wait for
clients to block/unblock.
- Add a pre-existing element to target list on basic tests so
that we can check if the new element was added to the correct
side of the list.
- check command stats on the replica to make sure the right
command was replicated
Co-authored-by: Oran Agra <oran@redislabs.com>
track and report memory used by clients argv.
this is very usaful in case clients started sending a command and didn't
complete it. in which case the first args of the command are already
trimmed from the query buffer.
in an effort to avoid cache misses and overheads while keeping track of
these, i avoid calling sdsZmallocSize and instead use the sdslen /
bulk-len which can at least give some insight into the problem.
This memory is now added to the total clients memory usage, as well as
the client list.
Before this commit, we would have continued to add replies to the reply buffer even if client
output buffer limit is reached, so the used memory would keep increasing over the configured limit.
What's more, we shouldn’t write any reply to the client if it is set 'CLIENT_CLOSE_ASAP' flag
because that doesn't conform to its definition and we will close all clients flagged with
'CLIENT_CLOSE_ASAP' in ‘beforeSleep’.
Because of code execution order, before this, we may firstly write to part of the replies to
the socket before disconnecting it, but in fact, we may can’t send the full replies to clients
since OS socket buffer is limited. But this unexpected behavior makes some commands work well,
for instance ACL DELUSER, if the client deletes the current user, we need to send reply to client
and close the connection, but before, we close the client firstly and write the reply to reply
buffer. secondly, we shouldn't do this despite the fact it works well in most cases.
We add a flag 'CLIENT_CLOSE_AFTER_COMMAND' to mark clients, this flag means we will close the
client after executing commands and send all entire replies, so that we can write replies to
reply buffer during executing commands, send replies to clients, and close them later.
We also fix some implicit problems. If client output buffer limit is enforced in 'multi/exec',
all commands will be executed completely in redis and clients will not read any reply instead of
partial replies. Even more, if the client executes 'ACL deluser' the using user in 'multi/exec',
it will not read the replies after 'ACL deluser' just like before executing 'client kill' itself
in 'multi/exec'.
We added some tests for output buffer limit breach during multi-exec and using a pipeline of
many small commands rather than one with big response.
Co-authored-by: Oran Agra <oran@redislabs.com>
Refine comment of makeThreadKillable().
This commit can be backported to 5.0, only if we also backport 8b70cb0.
Co-authored-by: Oran Agra <oran@redislabs.com>
We're already using bg_unlink in several places to delete the rdb file in the background,
and avoid paying the cost of the deletion from our main thread.
This commit uses bg_unlink to remove the temporary rdb file in the background too.
However, in case we delete that rdb file just before exiting, we don't actually wait for the
background thread or the main thread to delete it, and just let the OS clean up after us.
i.e. we open the file, unlink it and exit with the fd still open.
Furthermore, rdbRemoveTempFile can be called from a thread and was using snprintf which is
not async-signal-safe, we now use ll2string instead.
Redis 6.0 introduces I/O threads, it is so cool and efficient, we use C11
_Atomic to establish inter-thread synchronization without mutex. But the
compiler that must supports C11 _Atomic can compile redis code, that brings a
lot of inconvenience since some common platforms can't support by default such
as CentOS7, so we want to implement redis atomic type to make it more portable.
We have implemented our atomic variable for redis that only has 'relaxed'
operations in src/atomicvar.h, so we implement some operations with
'sequentially-consistent', just like the default behavior of C11 _Atomic that
can establish inter-thread synchronization. And we replace all uses of C11
_Atomic with redis atomic variable.
Our implementation of redis atomic variable uses C11 _Atomic, __atomic or
__sync macros if available, it supports most common platforms, and we will
detect automatically which feature we use. In Makefile we use a dummy file to
detect if the compiler supports C11 _Atomic. Now for gcc, we can compile redis
code theoretically if your gcc version is not less than 4.1.2(starts to support
__sync_xxx operations). Otherwise, we remove use mutex fallback to implement
redis atomic variable for performance and test. You will get compiling errors
if your compiler doesn't support all features of above.
For cover redis atomic variable tests, we add other CI jobs that build redis on
CentOS6 and CentOS7 and workflow daily jobs that run the tests on them.
For them, we just install gcc by default in order to cover different compiler
versions, gcc is 4.4.7 by default installation on CentOS6 and 4.8.5 on CentOS7.
We restore the feature that we can test redis with Helgrind to find data race
errors. But you need install Valgrind in the default path configuration firstly
before running your tests, since we use macros in helgrind.h to tell Helgrind
inter-thread happens-before relationship explicitly for avoiding false positives.
Please open an issue on github if you find data race errors relate to this commit.
Unrelated:
- Fix redefinition of typedef 'RedisModuleUserChangedFunc'
For some old version compilers, they will report errors or warnings, if we
re-define function type.
If one thread got SIGSEGV, function sigsegvHandler() would be triggered,
it would call bioKillThreads(). But call pthread_cancel() to cancel itself
would make it block. Also note that if SIGSEGV is caught by bio thread, it
should kill the main thread in order to give a positive report.
Rather than blindly evicting until maxmemory limit is achieved, this
update adds a time limit to eviction. While over the maxmemory limit,
eviction will process before each command AND as a timeProc when no
commands are running.
This will reduce the latency impact on many cases, especially pathological
cases like massive used memory increase during dict rehashing.
There is a risk that some other edge cases (like massive pipelined use
of MGET) could cause Redis memory usage to keep growing despite the
eviction attempts, so a new maxmemory-eviction-tenacity config is
introduced to let users mitigate that.
This is a catch-all test to confirm that that rewrite produces a valid
output for all parameters and that this process does not introduce
undesired configuration changes.
Starting redis 6.0 and the changes we made to the diskless master to be
suitable for TLS, I made the master avoid reaping (wait3) the pid of the
child until we know all replicas are done reading their rdb.
I did that in order to avoid a state where the rdb_child_pid is -1 but
we don't yet want to start another fork (still busy serving that data to
replicas).
It turns out that the solution used so far was problematic in case the
fork child was being killed (e.g. by the kernel OOM killer), in that
case there's a chance that we currently disabled the read event on the
rdb pipe, since we're waiting for a replica to become writable again.
and in that scenario the master would have never realized the child
exited, and the replica will remain hung too.
Note that there's no mechanism to detect a hung replica while it's in
rdb transfer state.
The solution here is to add another pipe which is used by the parent to
tell the child it is safe to exit. this mean that when the child exits,
for whatever reason, it is safe to reap it.
Besides that, i'm re-introducing an adjustment to REPLCONF ACK which was
part of #6271 (Accelerate diskless master connections) but was dropped
when that PR was rebased after the TLS fork/pipe changes (5a47794).
Now that RdbPipeCleanup no longer calls checkChildrenDone, and the ACK
has chance to detect that the child exited, it should be the one to call
it so that we don't have to wait for cron (server.hz) to do that.
During long running scripts or loading RDB/AOF, we may need to do some
defragging. Since processEventsWhileBlocked is called periodically at
unknown intervals, and many cron jobs either depend on run_with_period
(including active defrag), or rely on being called at server.hz rate
(i.e. active defrag knows ho much time to run by looking at server.hz),
the whileBlockedCron may have to run a loop triggering the cron jobs in it
(currently only active defrag) several times.
Other changes:
- Adding a test for defrag during aof loading.
- Changing key-load-delay config to take negative values for fractions
of a microsecond sleep
Update adds a general source for retrieving a monotonic time.
In addition, AE has been updated to utilize the new monotonic
clock for timer processing.
This performance improvement is **not** enabled in a default build due to various H/W compatibility
concerns, see README.md for details. It does however change the default use of gettimeofday with
clock_gettime and somewhat improves performance.
This update provides the following
1. An interface for retrieving a monotonic clock. getMonotonicUs returns a uint64_t (aka monotime)
with the number of micro-seconds from an arbitrary point. No more messing with tv_sec/tv_usec.
Simple routines are provided for measuring elapsed milli-seconds or elapsed micro-seconds (the
most common use case for a monotonic timer). No worries about time moving backwards.
2. High-speed assembler implementation for x86 and ARM. The standard method for retrieving the
monotonic clock is POSIX.1b (1993): clock_gettime(CLOCK_MONOTONIC, timespec*). However, most
modern processors provide a constant speed instruction clock which can be retrieved in a fraction
of the time that it takes to call clock_gettime. For x86, this is provided by the RDTSC
instruction. For ARM, this is provided by the CNTVCT_EL0 instruction. As a compile-time option,
these high-speed timers can be chosen. (Default is POSIX clock_gettime.)
3. Refactor of event loop timers. The timer processing in ae.c has been refactored to use the new
monotonic clock interface. This results in simpler/cleaner logic and improved performance.
65a3307bc (released in 6.0.6) has a side effect, when processCommand
rejects a command with pre-made shared object error string, it trims the
newlines from the end of the string. if that string is later used with
addReply, the newline will be missing, breaking the protocol, and
leaving the client hung.
It seems that the only scenario which this happens is when replying with
-LOADING to some command, and later using that reply from the CONFIG
SET command (still during loading). this will result in hung client.
Refactoring the code in order to avoid trimming these newlines from
shared string objects, and do the newline trimming only in other cases
where it's needed.
Co-authored-by: Guy Benoish <guy.benoish@redislabs.com>
During a long AOF or RDB loading, the memory stats were not updated, and
INFO would return stale data, specifically about fragmentation and RSS.
In the past some of these were sampled directly inside the INFO command,
but were moved to cron as an optimization.
This commit introduces a concept of loadingCron which should take
some of the responsibilities of serverCron.
It attempts to limit it's rate to approximately the server Hz, but may
not be very accurate.
In order to avoid too many system call, we use the cached ustime, and
also make sure to update it in both AOF loading and RDB loading inside
processEventsWhileBlocked (it seems AOF loading was missing it).
If the server gets MULTI command followed by only read
commands, and right before it gets the EXEC it reaches OOM,
the client will get OOM response.
So, from now on, it will get OOM response only if there was
at least one command that was tagged with `use-memory` flag
After fork, the child process(redis-aof-rewrite) will get the fd opened
by the parent process(redis), when redis killed by kill -9, it will not
graceful exit(call prepareForShutdown()), so redis-aof-rewrite thread may still
alive, the fd(lock) will still be held by redis-aof-rewrite thread, and
redis restart will fail to get lock, means fail to start.
This issue was causing failures in the cluster tests in github actions.
Co-authored-by: Oran Agra <oran@redislabs.com>
Since users often post just the crash log in github issues, the log
print that's above it is missing.
No reason not to include the size in the panic message itself.
Add Linux kernel OOM killer control option.
This adds the ability to control the Linux OOM killer oom_score_adj
parameter for all Redis processes, depending on the process role (i.e.
master, replica, background child).
A oom-score-adj global boolean flag control this feature. In addition,
specific values can be configured using oom-score-adj-values if
additional tuning is required.
This is a rebased version of #3078 originally by shaharmor
with the following patches by TysonAndre made after rebasing
to work with the updated C API:
1. Add 2 more unit tests
(wrong argument count error message, integer over 64 bits)
2. Use addReplyArrayLen instead of addReplyMultiBulkLen.
3. Undo changes to src/help.h - for the ZMSCORE PR,
I heard those should instead be automatically
generated from the redis-doc repo if it gets updated
Motivations:
- Example use case: Client code to efficiently check if each element of a set
of 1000 items is a member of a set of 10 million items.
(Similar to reasons for working on #7593)
- HMGET and ZMSCORE already exist. This may lead to developers deciding
to implement functionality that's best suited to a regular set with a
data type of sorted set or hash map instead, for the multi-get support.
Currently, multi commands or lua scripting to call sismember multiple times
would almost definitely be less efficient than a native smismember
for the following reasons:
- Need to fetch the set from the string every time
instead of reusing the C pointer.
- Using pipelining or multi-commands would result in more bytes sent
and received by the client for the repeated SISMEMBER KEY sections.
- Need to specially encode the data and decode it from the client
for lua-based solutions.
- Proposed solutions using Lua or SADD/SDIFF could trigger writes to
memory, which is undesirable on a redis replica server
or when commands get replicated to replicas.
Co-Authored-By: Shahar Mor <shahar@peer5.com>
Co-Authored-By: Tyson Andre <tysonandre775@hotmail.com>
Before this fix we where attempting to select a db before creating db the DB, see: #7323
This issue doesn't seem to have any implications, since the selected DB index is 0,
the db pointer remains NULL, and will later be correctly set before using this dummy
client for the first time.
As we know, we call 'moduleInitModulesSystem()' before 'initServer()'. We will allocate
memory for server.db in 'initServer', but we call 'createClient()' that will call 'selectDb()'
in 'moduleInitModulesSystem()', before the databases where created. Instead, we should call
'createClient()' for moduleFreeContextReusedClient after 'initServer()'.
Diskless master has some inherent latencies.
1) fork starts with delay from cron rather than immediately
2) replica is put online only after an ACK. but the ACK
was sent only once a second.
3) but even if it would arrive immediately, it will not
register in case cron didn't yet detect that the fork is done.
Besides that, when a replica disconnects, it doesn't immediately
attempts to re-connect, it waits for replication cron (one per second).
in case it was already online, it may be important to try to re-connect
as soon as possible, so that the backlog at the master doesn't vanish.
In case it disconnected during rdb transfer, one can argue that it's
not very important to re-connect immediately, but this is needed for the
"diskless loading short read" test to be able to run 100 iterations in 5
seconds, rather than 3 (waiting for replication cron re-connection)
changes in this commit:
1) sync command starts a fork immediately if no sync_delay is configured
2) replica sends REPLCONF ACK when done reading the rdb (rather than on 1s cron)
3) when a replica unexpectedly disconnets, it immediately tries to
re-connect rather than waiting 1s
4) when when a child exits, if there is another replica waiting, we spawn a new
one right away, instead of waiting for 1s replicationCron.
5) added a call to connectWithMaster from replicationSetMaster. which is called
from the REPLICAOF command but also in 3 places in cluster.c, in all of
these the connection attempt will now be immediate instead of delayed by 1
second.
side note:
we can add a call to rdbPipeReadHandler in replconfCommand when getting
a REPLCONF ACK from the replica to solve a race where the replica got
the entire rdb and EOF marker before we detected that the pipe was
closed.
in the test i did see this race happens in one about of some 300 runs,
but i concluded that this race is unlikely in real life (where the
replica is on another host and we're more likely to first detect the
pipe was closed.
the test runs 100 iterations in 3 seconds, so in some cases it'll take 4
seconds instead (waiting for another REPLCONF ACK).
Removing unneeded startBgsaveForReplication from updateSlavesWaitingForBgsave
Now that CheckChildrenDone is calling the new replicationStartPendingFork
(extracted from serverCron) there's actually no need to call
startBgsaveForReplication from updateSlavesWaitingForBgsave anymore,
since as soon as updateSlavesWaitingForBgsave returns, CheckChildrenDone is
calling replicationStartPendingFork that handles that anyway.
The code in updateSlavesWaitingForBgsave had a bug in which it ignored
repl-diskless-sync-delay, but removing that code shows that this bug was
hiding another bug, which is that the max_idle should have used >= and
not >, this one second delay has a big impact on my new test.
This makes it possible to add tests that generate assertions, and run
them with valgrind, making sure that there are no memory violations
prior to the assertion.
New config options:
- crash-log-enabled - can be disabled for cleaner core dumps
- crash-memcheck-enabled - useful for faster termination after a crash
- use-exit-on-panic - to be used by the test suite so that valgrind can
detect leaks and memory corruptions
Other changes:
- Crash log is printed even on system that dont HAVE_BACKTRACE, i.e. in
both SIGSEGV and assert / panic
- Assertion and panic won't print registers and code around EIP (which
was useless), but will do fast memory test (which may still indicate
that the assertion was due to memory corrpution)
I had to reshuffle code in order to re-use it, so i extracted come code
into function without actually doing any changes to the code:
- logServerInfo
- logModulesInfo
- doFastMemoryTest (with the exception of it being conditional)
- dumpCodeAroundEIP
changes to the crash report on segfault:
- logRegisters is called right after the stack trace (before info) done
just in order to have more re-usable code
- stack trace skips the first two items on the stack (the crash log and
signal handler functions)
Syntax: `ZMSCORE KEY MEMBER [MEMBER ...]`
This is an extension of #2359
amended by Tyson Andre to work with the changed unstable API,
add more tests, and consistently return an array.
- It seemed as if it would be more likely to get reviewed
after updating the implementation.
Currently, multi commands or lua scripting to call zscore multiple times
would almost definitely be less efficient than a native ZMSCORE
for the following reasons:
- Need to fetch the set from the string every time instead of reusing the C
pointer.
- Using pipelining or multi-commands would result in more bytes sent by
the client for the repeated `ZMSCORE KEY` sections.
- Need to specially encode the data and decode it from the client
for lua-based solutions.
- The fastest solution I've seen for large sets(thousands or millions)
involves lua and a variadic ZADD, then a ZINTERSECT, then a ZRANGE 0 -1,
then UNLINK of a temporary set (or lua). This is still inefficient.
Co-authored-by: Tyson Andre <tysonandre775@hotmail.com>
Initialize and configure OpenSSL even when tls-port is not used, because
we may still have tls-cluster or tls-replication.
Also, make sure to reconfigure OpenSSL when these parameters are changed
as TLS could have been enabled for the first time.
Before that PR, processCommand() did not notice that cmd could be a module
command in which case getkeys_proc member has a different meaning.
The outcome was that a module command which doesn't take any key names in its
arguments (similar to SLOWLOG) would be handled as if it might have key name arguments
(similar to MEMORY), would consider cluster redirect but will end up with 0 keys
after an excessive call to getKeysFromCommand, and eventually do the right thing.
Before this commit, processCommand() did not notice that cmd could be a module command
which declared `getkeys-api` and handled it for the purpose of cluster redirect it
as if it doesn't use any keys.
This commit fixed it by reusing the codes in addReplyCommand().
In order to support the use of multi-exec in pipeline, it is important that
MULTI and EXEC are never rejected and it is easy for the client to know if the
connection is still in multi state.
It was easy to make sure MULTI and DISCARD never fail (done by previous
commits) since these only change the client state and don't do any actual
change in the server, but EXEC is a different story.
Since in the past, it was possible for clients to handle some EXEC errors and
retry the EXEC, we now can't affort to return any error on EXEC other than
EXECABORT, which now carries with it the real reason for the abort too.
Other fixes in this commit:
- Some checks that where performed at the time of queuing need to be re-
validated when EXEC runs, for instance if the transaction contains writes
commands, it needs to be aborted. there was one check that was already done
in execCommand (-READONLY), but other checks where missing: -OOM, -MISCONF,
-NOREPLICAS, -MASTERDOWN
- When a command is rejected by processCommand it was rejected with addReply,
which was not recognized as an error in case the bad command came from the
master. this will enable to count or MONITOR these errors in the future.
- make it easier for tests to create additional (non deferred) clients.
- add tests for the fixes of this commit.
The `LRANK` command returns the index (position) of a given element
within a list. Using the `direction` argument it is possible to specify
going from head to tail (acending, 1) or from tail to head (decending,
-1). Only the first found index is returend. The complexity is O(N).
When using lists as a queue it can be of interest at what position a
given element is, for instance to monitor a job processing through a
work queue. This came up within the Python `rq` project which is based
on Redis[0].
[0]: https://github.com/rq/rq/issues/1197
Signed-off-by: Paul Spooren <mail@aparcar.org>
Much like MULTI/EXEC/DISCARD, the WATCH and UNWATCH are not actually
operating on the database or server state, but instead operate on the
client state. the client may send them all in one long pipeline and check
all the responses only at the end, so failing them may lead to a
mismatch between the client state on the server and the one on the
client end, and execute the wrong commands (ones that were meant to be
discarded)
the watched keys are not actually stored in the client struct, but they
are in fact part of the client state. for instance, they're not cleared
or moved in SWAPDB or FLUSHDB.
After a closer look, the Redis core devleopers all believe that this was
too fragile, caused many bugs that we didn't expect and that were very
hard to track. Better to find an alternative solution that is simpler.
This bug was introduced by a recent change in which readQueryFromClient
is using freeClientAsync, and despite the fact that now
freeClientsInAsyncFreeQueue is in beforeSleep, that's not enough since
it's not called during loading in processEventsWhileBlocked.
furthermore, afterSleep was called in that case but beforeSleep wasn't.
This bug also caused slowness sine the level-triggered mode of epoll
kept signaling these connections as readable causing us to keep doing
connRead again and again for ll of these, which keep accumulating.
now both before and after sleep are called, but not all of their actions
are performed during loading, some are only reserved for the main loop.
fixes issue #7215
Currently, there are several types of threads/child processes of a
redis server. Sometimes we need deeply optimise the performance of
redis, so we would like to isolate threads/processes.
There were some discussion about cpu affinity cases in the issue:
https://github.com/antirez/redis/issues/2863
So implement cpu affinity setting by redis.conf in this patch, then
we can config server_cpulist/bio_cpulist/aof_rewrite_cpulist/
bgsave_cpulist by cpu list.
Examples of cpulist in redis.conf:
server_cpulist 0-7:2 means cpu affinity 0,2,4,6
bio_cpulist 1,3 means cpu affinity 1,3
aof_rewrite_cpulist 8-11 means cpu affinity 8,9,10,11
bgsave_cpulist 1,10-11 means cpu affinity 1,10,11
Test on linux/freebsd, both work fine.
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
If client gets blocked again in `processUnblockedClients`, redis will not send
`REPLCONF GETACK *` to slaves untill next eventloop, so the client will be
blocked for 100ms by default(10hz) if no other file event fired.
move server.get_ack_from_slaves sinppet after `processUnblockedClients`, so
that both the first WAIT command that puts client in blocked context and the
following WAIT command processed in processUnblockedClients would trigger
redis-sever to send `REPLCONF GETACK *`, so that the eventloop would get
`REPLCONG ACK <reploffset>` from slaves and unblocked ASAP.
come to think of it, in theory (not in practice), getDecodedObject can
return the same original object with refcount incremented, so the
pointer comparision in the previous commit was invalid.
so now instead of checking the encoding, we explicitly check the
refcount.
since the recent addition of OBJ_STATIC_REFCOUNT and the assertion in
incrRefCount it is now impossible to use dictFind using a static robj,
because dictEncObjKeyCompare will call getDecodedObject which tries to
increment the refcount just in order to decrement it later.
STRALGO should be a container for mostly read-only string
algorithms in Redis. The algorithms should have two main
characteristics:
1. They should be non trivial to compute, and often not part of
programming language standard libraries.
2. They should be fast enough that it is a good idea to have optimized C
implementations.
Next thing I would love to see? A small strings compression algorithm.
If redis crashes early, before lua is set up (like, if File Descriptor 0 is closed before exec), it will crash again trying to print memory statistics.
Related to #5145.
Design note: clients may change type when they turn into replicas or are
moved into the Pub/Sub category and so forth. Moreover the recomputation
of the bytes used is problematic for obvious reasons: it changes
continuously, so as a conservative way to avoid accumulating errors,
each client remembers the contribution it gave to the sum, and removes
it when it is freed or before updating it with the new memory usage.
Example: Client uses a pipe to send the following to a
stale replica:
MULTI
.. do something ...
DISCARD
The replica will reply the MUTLI with -MASTERDOWN and
execute the rest of the commands... A client using a
pipe might not be aware that MULTI failed until it's
too late.
I can't think of a reason why MULTI/EXEC/DISCARD should
not be executed on stale replicas...
Also, enable MULTI/EXEC/DISCARD during loading
Makse sure call() doesn't wrap replicated commands with
a redundant MULTI/EXEC
Other, unrelated changes:
1. Formatting compiler warning in INFO CLIENTS
2. Use CLIENT_ID_AOF instead of UINT64_MAX
37a10cef introduced automatic wrapping of MULTI/EXEC for the
alsoPropagate API. However this collides with the built-in mechanism
already present in module.c. To avoid complex changes near Redis 6 GA
this commit introduces the ability to exclude call() MUTLI/EXEC wrapping
for also propagate in order to continue to use the old code paths in
module.c.
Now that this mechanism is the sole one used for blocked clients
timeouts, it is more wise to cleanup the table when the client unblocks
for any reason. We use a flag: CLIENT_IN_TO_TABLE, in order to avoid a
radix tree lookup when the client was already removed from the table
because we processed it by scanning the radix tree.
A very commonly signaled operational problem with Redis master-replicas
sets is that, once the master becomes unavailable for some reason,
especially because of network problems, many times it wont be able to
perform a partial resynchronization with the new master, once it rejoins
the partition, for the following reason:
1. The master becomes isolated, however it keeps sending PINGs to the
replicas. Such PINGs will never be received since the link connection is
actually already severed.
2. On the other side, one of the replicas will turn into the new master,
setting its secondary replication ID offset to the one of the last
command received from the old master: this offset will not include the
PINGs sent by the master once the link was already disconnected.
3. When the master rejoins the partion and is turned into a replica, its
offset will be too advanced because of the PINGs, so a PSYNC will fail,
and a full synchronization will be required.
Related to issue #7002 and other discussion we had in the past around
this problem.
Redis refusing to run MULTI or EXEC during script timeout may cause partial
transactions to run.
1) if the client sends MULTI+commands+EXEC in pipeline without waiting for
response, but these arrive to the shards partially while there's a busy script,
and partially after it eventually finishes: we'll end up running only part of
the transaction (since multi was ignored, and exec would fail).
2) similar to the above if EXEC arrives during busy script, it'll be ignored and
the client state remains in a transaction.
the 3rd test which i added for a case where MULTI and EXEC are ok, and
only the body arrives during busy script was already handled correctly
since processCommand calls flagTransaction
Before this commit, when upgrading a replica, expired keys will not
be loaded, thus causing replica having less keys in db. To this point,
master and replica's keys is logically consistent. However, before
the keys in master and replica are physically consistent, that is,
they have the same dbsize, if master got a problem and the replica
got promoted and becomes new master of that partition, and master
updates a key which does not exist on master, but physically exists
on the old master(new replica), the old master would refuse to update
the key, thus causing master and replica data inconsistent.
How could this happen?
That's all because of the wrong judgement of roles while starting up
the server. We can not use server.masterhost to judge if the server
is master or replica, since it fails in cluster mode.
When we start the server, we load rdb and do want to load expired keys,
and do not want to have the ability to active expire keys, if it is
a replica.
guybe7