# Redis Function Libraries
This PR implements Redis Functions Libraries as describe on: https://github.com/redis/redis/issues/9906.
Libraries purpose is to provide a better code sharing between functions by allowing to create multiple
functions in a single command. Functions that were created together can safely share code between
each other without worrying about compatibility issues and versioning.
Creating a new library is done using 'FUNCTION LOAD' command (full API is described below)
This PR introduces a new struct called libraryInfo, libraryInfo holds information about a library:
* name - name of the library
* engine - engine used to create the library
* code - library code
* description - library description
* functions - the functions exposed by the library
When Redis gets the `FUNCTION LOAD` command it creates a new empty libraryInfo.
Redis passes the `CODE` to the relevant engine alongside the empty libraryInfo.
As a result, the engine will create one or more functions by calling 'libraryCreateFunction'.
The new funcion will be added to the newly created libraryInfo. So far Everything is happening
locally on the libraryInfo so it is easy to abort the operation (in case of an error) by simply
freeing the libraryInfo. After the library info is fully constructed we start the joining phase by
which we will join the new library to the other libraries currently exist on Redis.
The joining phase make sure there is no function collision and add the library to the
librariesCtx (renamed from functionCtx). LibrariesCtx is used all around the code in the exact
same way as functionCtx was used (with respect to RDB loading, replicatio, ...).
The only difference is that apart from function dictionary (maps function name to functionInfo
object), the librariesCtx contains also a libraries dictionary that maps library name to libraryInfo object.
## New API
### FUNCTION LOAD
`FUNCTION LOAD <ENGINE> <LIBRARY NAME> [REPLACE] [DESCRIPTION <DESCRIPTION>] <CODE>`
Create a new library with the given parameters:
* ENGINE - REPLACE Engine name to use to create the library.
* LIBRARY NAME - The new library name.
* REPLACE - If the library already exists, replace it.
* DESCRIPTION - Library description.
* CODE - Library code.
Return "OK" on success, or error on the following cases:
* Library name already taken and REPLACE was not used
* Name collision with another existing library (even if replace was uses)
* Library registration failed by the engine (usually compilation error)
## Changed API
### FUNCTION LIST
`FUNCTION LIST [LIBRARYNAME <LIBRARY NAME PATTERN>] [WITHCODE]`
Command was modified to also allow getting libraries code (so `FUNCTION INFO` command is no longer
needed and removed). In addition the command gets an option argument, `LIBRARYNAME` allows you to
only get libraries that match the given `LIBRARYNAME` pattern. By default, it returns all libraries.
### INFO MEMORY
Added number of libraries to `INFO MEMORY`
### Commands flags
`DENYOOM` flag was set on `FUNCTION LOAD` and `FUNCTION RESTORE`. We consider those commands
as commands that add new data to the dateset (functions are data) and so we want to disallows
to run those commands on OOM.
## Removed API
* FUNCTION CREATE - Decided on https://github.com/redis/redis/issues/9906
* FUNCTION INFO - Decided on https://github.com/redis/redis/issues/9899
## Lua engine changes
When the Lua engine gets the code given on `FUNCTION LOAD` command, it immediately runs it, we call
this run the loading run. Loading run is not a usual script run, it is not possible to invoke any
Redis command from within the load run.
Instead there is a new API provided by `library` object. The new API's:
* `redis.log` - behave the same as `redis.log`
* `redis.register_function` - register a new function to the library
The loading run purpose is to register functions using the new `redis.register_function` API.
Any attempt to use any other API will result in an error. In addition, the load run is has a time
limit of 500ms, error is raise on timeout and the entire operation is aborted.
### `redis.register_function`
`redis.register_function(<function_name>, <callback>, [<description>])`
This new API allows users to register a new function that will be linked to the newly created library.
This API can only be called during the load run (see definition above). Any attempt to use it outside
of the load run will result in an error.
The parameters pass to the API are:
* function_name - Function name (must be a Lua string)
* callback - Lua function object that will be called when the function is invokes using fcall/fcall_ro
* description - Function description, optional (must be a Lua string).
### Example
The following example creates a library called `lib` with 2 functions, `f1` and `f1`, returns 1 and 2 respectively:
```
local function f1(keys, args)
return 1
end
local function f2(keys, args)
return 2
end
redis.register_function('f1', f1)
redis.register_function('f2', f2)
```
Notice: Unlike `eval`, functions inside a library get the KEYS and ARGV as arguments to the
functions and not as global.
### Technical Details
On the load run we only want the user to be able to call a white list on API's. This way, in
the future, if new API's will be added, the new API's will not be available to the load run
unless specifically added to this white list. We put the while list on the `library` object and
make sure the `library` object is only available to the load run by using [lua_setfenv](https://www.lua.org/manual/5.1/manual.html#lua_setfenv) API. This API allows us to set
the `globals` of a function (and all the function it creates). Before starting the load run we
create a new fresh Lua table (call it `g`) that only contains the `library` API (we make sure
to set global protection on this table just like the general global protection already exists
today), then we use [lua_setfenv](https://www.lua.org/manual/5.1/manual.html#lua_setfenv)
to set `g` as the global table of the load run. After the load run finished we update `g`
metatable and set `__index` and `__newindex` functions to be `_G` (Lua default globals),
we also pop out the `library` object as we do not need it anymore.
This way, any function that was created on the load run (and will be invoke using `fcall`) will
see the default globals as it expected to see them and will not have the `library` API anymore.
An important outcome of this new approach is that now we can achieve a distinct global table
for each library (it is not yet like that but it is very easy to achieve it now). In the future we can
decide to remove global protection because global on different libraries will not collide or we
can chose to give different API to different libraries base on some configuration or input.
Notice that this technique was meant to prevent errors and was not meant to prevent malicious
user from exploit it. For example, the load run can still save the `library` object on some local
variable and then using in `fcall` context. To prevent such a malicious use, the C code also make
sure it is running in the right context and if not raise an error.
Following #10038.
This PR introduces two changes.
1. Show the elapsed time of a single test in the test output, in order to have a more
detailed understanding of the changes in test run time.
2. Speedup two tests related to `key-load-delay` configuration.
other tests do not seem to be affected by #10003.
Implement Multi-Part AOF mechanism to avoid overheads during AOFRW.
Introducing a folder with multiple AOF files tracked by a manifest file.
The main issues with the the original AOFRW mechanism are:
* buffering of commands that are processed during rewrite (consuming a lot of RAM)
* freezes of the main process when the AOFRW completes to drain the remaining part of the buffer and fsync it.
* double disk IO for the data that arrives during AOFRW (had to be written to both the old and new AOF files)
The main modifications of this PR:
1. Remove the AOF rewrite buffer and related code.
2. Divide the AOF into multiple files, they are classified as two types, one is the the `BASE` type,
it represents the full amount of data (Maybe AOF or RDB format) after each AOFRW, there is only
one `BASE` file at most. The second is `INCR` type, may have more than one. They represent the
incremental commands since the last AOFRW.
3. Use a AOF manifest file to record and manage these AOF files mentioned above.
4. The original configuration of `appendfilename` will be the base part of the new file name, for example:
`appendonly.aof.1.base.rdb` and `appendonly.aof.2.incr.aof`
5. Add manifest-related TCL tests, and modified some existing tests that depend on the `appendfilename`
6. Remove the `aof_rewrite_buffer_length` field in info.
7. Add `aof-disable-auto-gc` configuration. By default we're automatically deleting HISTORY type AOFs.
It also gives users the opportunity to preserve the history AOFs. just for testing use now.
8. Add AOFRW limiting measure. When the AOFRW failures reaches the threshold (3 times now),
we will delay the execution of the next AOFRW by 1 minute. If the next AOFRW also fails, it will be
delayed by 2 minutes. The next is 4, 8, 16, the maximum delay is 60 minutes (1 hour). During the limit
period, we can still use the 'bgrewriteaof' command to execute AOFRW immediately.
9. Support upgrade (load) data from old version redis.
10. Add `appenddirname` configuration, as the directory name of the append only files. All AOF files and
manifest file will be placed in this directory.
11. Only the last AOF file (BASE or INCR) can be truncated. Otherwise redis will exit even if
`aof-load-truncated` is enabled.
Co-authored-by: Oran Agra <oran@redislabs.com>
This commit adds DUMP RESTORES tests for the -x and -X options.
I wanted to add it in #9980 which introduce the -X option, but
back then i failed due to some errors (related to redis-cli call).
To avoid data loss, this commit adds a grace period for lagging replicas to
catch up the replication offset.
Done:
* Wait for replicas when shutdown is triggered by SIGTERM and SIGINT.
* Wait for replicas when shutdown is triggered by the SHUTDOWN command. A new
blocked client type BLOCKED_SHUTDOWN is introduced, allowing multiple clients
to call SHUTDOWN in parallel.
Note that they don't expect a response unless an error happens and shutdown is aborted.
* Log warning for each replica lagging behind when finishing shutdown.
* CLIENT_PAUSE_WRITE while waiting for replicas.
* Configurable grace period 'shutdown-timeout' in seconds (default 10).
* New flags for the SHUTDOWN command:
- NOW disables the grace period for lagging replicas.
- FORCE ignores errors writing the RDB or AOF files which would normally
prevent a shutdown.
- ABORT cancels ongoing shutdown. Can't be combined with other flags.
* New field in the output of the INFO command: 'shutdown_in_milliseconds'. The
value is the remaining maximum time to wait for lagging replicas before
finishing the shutdown. This field is present in the Server section **only**
during shutdown.
Not directly related:
* When shutting down, if there is an AOF saving child, it is killed **even** if AOF
is disabled. This can happen if BGREWRITEAOF is used when AOF is off.
* Client pause now has end time and type (WRITE or ALL) per purpose. The
different pause purposes are *CLIENT PAUSE command*, *failover* and
*shutdown*. If clients are unpaused for one purpose, it doesn't affect client
pause for other purposes. For example, the CLIENT UNPAUSE command doesn't
affect client pause initiated by the failover or shutdown procedures. A completed
failover or a failed shutdown doesn't unpause clients paused by the CLIENT
PAUSE command.
Notes:
* DEBUG RESTART doesn't wait for replicas.
* We already have a warning logged when a replica disconnects. This means that
if any replica connection is lost during the shutdown, it is either logged as
disconnected or as lagging at the time of exit.
Co-authored-by: Oran Agra <oran@redislabs.com>
This is needed in order to ease the deployment of functions for ephemeral cases, where user
needs to spin up a server with functions pre-loaded.
#### Details:
* Added `--functions-rdb` option to _redis-cli_.
* Functions only rdb via `REPLCONF rdb-filter-only functions`. This is a placeholder for a space
separated inclusion filter for the RDB. In the future can be `REPLCONF rdb-filter-only
"functions db:3 key-patten:user*"` and a complementing `rdb-filter-exclude` `REPLCONF`
can also be added.
* Handle "slave requirements" specification to RDB saving code so we can use the same RDB
when different slaves express the same requirements (like functions-only) and not share the
RDB when their requirements differ. This is currently just a flags `int`, but can be extended to
a more complex structure with various filter fields.
* make sure to support filters only in diskless replication mode (not to override the persistence file),
we do that by forcing diskless (even if disabled by config)
other changes:
* some refactoring in rdb.c (extract portion of a big function to a sub-function)
* rdb_key_save_delay used in AOFRW too
* sendChildInfo takes the number of updated keys (incremental, rather than absolute)
Co-authored-by: Oran Agra <oran@redislabs.com>
This pr is mainly to solve the problem that redis process cannot be exited normally, due to changes in #10003.
When a test uses the `key-load-delay` config to delay loading, but does not reset it at the end of the test, will lead to server wait for the loading to reach the event
loop (once in 2mb) before actually shutting down.
There are two changes in this commit:
1. Add -X option to redis-cli.
Currently `-x` can only be used to provide the last argument,
so you can do `redis-cli dump keyname > key.dump`,
and then do `redis-cli -x restore keyname 0 < key.dump`.
But what if you want to add the replace argument (which comes last?).
oran suggested adding such usage:
`redis-cli -X <tag> restore keyname <tag> replace < key.dump`
i.e. you're able to provide a string in the arguments that's gonna be
substituted with the content from stdin.
Note that the tag name should not conflict with others non-replaced args.
And the -x and -X options are conflicting.
Some usages:
```
[root]# echo mypasswd | src/redis-cli -X passwd_tag mset username myname password passwd_tag OK
[root]# echo username > username.txt
[root]# head -c -1 username.txt | src/redis-cli -X name_tag mget name_tag password
1) "myname"
2) "mypasswd\n"
```
2. Handle the combination of both `-x` and `--cluster` or `-X` and `--cluster`
Extend the broadcast option to receive the last arg or <tag> arg from the stdin.
Now we can use `redis-cli -x --cluster call <host>:<port> cmd`,
or `redis-cli -X <tag> --cluster call <host>:<port> cmd <tag>`.
(support part of #9899)
issue started failing after #9878 was merged (made an exiting test more sensitive)
looks like #9982 didn't help, tested this one and it seems to work better.
this commit does two things:
1. reduce the extra delay i added earlier and instead add more keys, the effect no duration
of replication is the same, but the intervals in which the server is responsive to the tcl client is higher.
2. improve the test infra to print context when assert_error fails.
## 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>
- add needs:debug flag for some tests
- disable "save" in external tests (speedup?)
- use debug_digest proc instead of debug command directly so it can be skipped
- use OBJECT ENCODING instead of DEBUG OBJECT to get encoding
- add a proc for OBJECT REFCOUNT so it can be skipped
- move a bunch of tests in latency_monitor tests to happen later so that latency monitor has some values in it
- add missing close_replication_stream calls
- make sure to close the temp client if DEBUG LOG fails
When rdb creates a consumer without determining whether it exists in advance,
it may return NULL and crash if it encounters corrupt data with duplicate consumers.
A test failure was reported in Daily CI.
`Crash report generated on SIGABRT` with FreeBSD.
```
*** [err]: Crash report generated on SIGABRT in tests/integration/logging.tcl
Expected [string match *crashed by signal* ### Starting...(logs) in tests/integration/logging.tcl]
```
It look like `tail -1000` was executed too early, before it
printed out all the crash logs. We can give it a few more
chances by using `wait_for_log_messages`.
Other changes:
1. In `Server is able to generate a stack trace on selected systems`,
use `wait_for_log_messages`to reduce the lines of code. And if it
fails, there are more detailed logs that can be printed.
2. In `Crash report generated on DEBUG SEGFAULT`, we also use
`wait_for_log_messages` to avoid possible timing issues.
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.
Writable replicas now no longer use the values of expired keys. Expired keys are
deleted when lookupKeyWrite() is used, even on a writable replica. Previously,
writable replicas could use the value of an expired key in write commands such
as INCR, SUNIONSTORE, etc..
This commit also sorts out the mess around the functions lookupKeyRead() and
lookupKeyWrite() so they now indicate what we intend to do with the key and
are not affected by the command calling them.
Multi-key commands like SUNIONSTORE, ZUNIONSTORE, COPY and SORT with the
store option now use lookupKeyRead() for the keys they're reading from (which will
not allow reading from logically expired keys).
This commit also fixes a bug where PFCOUNT could return a value of an
expired key.
Test modules commands have their readonly and write flags updated to correctly
reflect their lookups for reading or writing. Modules are not required to
correctly reflect this in their command flags, but this change is made for
consistency since the tests serve as usage examples.
Fixes#6842. Fixes#7475.
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>
In #9323, when `repl-diskless-load` is enabled and set to `swapdb`,
if the master replication ID hasn't changed, we can load data-set
asynchronously, and serving read commands during the full resync.
In `diskless loading short read` test, after a loading successfully,
we will wait for the loading to stop and continue the for loop.
After the introduction of `async_loading`, we also need to check it.
Otherwise the next loop will start too soon, may trigger a timing issue.
Issue found by corrupt-dump-fuzzer test with ASAN.
The problem was that lpSkip and lpGetWithSize could read the next listpack entry without validating that it's in range.
Similarly even the memcmp in lpFind could do that and possibly crash on segfault and now they'll crash on assert first.
The naive fix of using lpAssertValidEntry every time, resulted in 30% degradation in the lpFind benchmark of the unit test.
The final fix with the condition at the bottom has no performance implications.
TCL8.5 can't handle cases where part of the string is escaped and part of it isn't,
if there's a single char that needs escaping, we need to escape the whole string.
Leak found by the corrupt-dump-fuzzer when using GCC ASAN, which seems
to falsely report leaks on pointers kept only on the stack when calling exit.
Instead we now use _exit on panic / assert to skip these leak checks.
Additionally, check for sanitizer warnings in the corrupt-dump-fuzzer between iterations,
so that when something is found we know which test to relate it too (and it prints reproduction command list)
LCS can allocate immense amount of memory (sizes of two inputs multiplied by each other).
In the past this caused some possible security issues due to overflows, which we solved
and also added use of `trymalloc` to return "Insufficient memory" instead of OOM panic zmalloc.
But in case overcommit is enabled, it could be that we won't get the OOM panic, and zmalloc
will succeed, and then we can get OOM killed by the kernel.
The solution here is to prevent LCS from allocating transient memory that's bigger than
`proto-max-bulk-len` config.
This config is not directly related to transient memory, but using a hard coded value ad well as
introducing a specific config seems wrong.
This comes to solve an error in the corrupt-dump-fuzzer test that started in the daily CI see #9799
- Added sanitizer support. `address`, `undefined` and `thread` sanitizers are available.
- To build Redis with desired sanitizer : `make SANITIZER=undefined`
- There were some sanitizer findings, cleaned up codebase
- Added tests with address and undefined behavior sanitizers to daily CI.
- Added tests with address sanitizer to the per-PR CI (smoke out mem leaks sooner).
Basically, there are three types of issues :
**1- Unaligned load/store** : Most probably, this issue may cause a crash on a platform that
does not support unaligned access. Redis does unaligned access only on supported platforms.
**2- Signed integer overflow.** Although, signed overflow issue can be problematic time to time
and change how compiler generates code, current findings mostly about signed shift or simple
addition overflow. For most platforms Redis can be compiled for, this wouldn't cause any issue
as far as I can tell (checked generated code on godbolt.org).
**3 -Minor leak** (redis-cli), **use-after-free**(just before calling exit());
UB means nothing guaranteed and risky to reason about program behavior but I don't think any
of the fixes here worth backporting. As sanitizers are now part of the CI, preventing new issues
will be the real benefit.
First, avoid using --accurate on the freebsd CI, we only care about
systematic issues there due to being different platform, but not
accuracy
Secondly, when looking at the test which timed out it seems silly and
outdated:
- it used KEYS to attempt to trigger lazy expiry, but KEYS doesn't do
that anymore.
- it used some hard coded sleeps rather than waiting for things to
happen and exiting ASAP
In both tests, "diskless loading short read" and "diskless loading short read with module",
the timeout of waiting for the replica to respond to a short read and log it, is too short.
Also, add --dump-logs in runtest-moduleapi for valgrind runs.
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>
When repl-diskless-load is enabled, the connection is set to the blocking state.
The connection may be interrupted by a signal during a system call.
This would have resulted in a disconnection and possibly a reconnection loop.
Co-authored-by: Oran Agra <oran@redislabs.com>
Redis lists are stored in quicklist, which is currently a linked list of ziplists.
Ziplists are limited to storing elements no larger than 4GB, so when bigger
items are added they're getting truncated.
This PR changes quicklists so that they're capable of storing large items
in quicklist nodes that are plain string buffers rather than ziplist.
As part of the PR there were few other changes in redis:
1. new DEBUG sub-commands:
- QUICKLIST-PACKED-THRESHOLD - set the threshold of for the node type to
be plan or ziplist. default (1GB)
- QUICKLIST <key> - Shows low level info about the quicklist encoding of <key>
2. rdb format change:
- A new type was added - RDB_TYPE_LIST_QUICKLIST_2 .
- container type (packed / plain) was added to the beginning of the rdb object
(before the actual node list).
3. testing:
- Tests that requires over 100MB will be by default skipped. a new flag was
added to 'runtest' to run the large memory tests (not used by default)
Co-authored-by: sundb <sundbcn@gmail.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
So it looks like sampling set loglines [count_log_lines -2] was
executed too late, and the replication managed to complete before that.
```
*** [err]: diskless no replicas drop during rdb pipe in tests/integration/replication.tcl
log message of '"*Diskless rdb transfer, done reading from pipe, 2 replicas still up*"' not found in ./tests/tmp/server.6124.69/stdout after line: 52 till line: 52
```
Changes:
1. when we search the master log file, we start to search from before we sent the REPLICAOF
command, to prevent a race in which the replication completed before we sampled the log line count.
2. we don't need to sample the replica loglines sine it's a fresh resplica that's just been started, so the message
we're looking for is the first occurrence in the log, we can start search from 0.
Co-authored-by: Oran Agra <oran@redislabs.com>
Test failed on freebsd:
```
*** [err]: Make the old master a replica of the new one and check conditions in tests/integration/psync2-pingoff.tcl
Expected '162' to be equal to '176' (context: type eval line 18 cmd {assert_equal [status $R(0) master_repl_offset] [status $R(1) master_repl_offset]} proc ::test)
```
There are two possible race conditions in the test.
1. The code waits for sync_full to increment, and assumes that means the
master did the fork. But in fact there are cases the master will increment
that sync_full counter (after replica asks for sync), but will see that
there's already a fork running and will delay the fork creation.
In this case the INCR will be executed before the fork happens, so it'll
not be in the command stream. Solve that by waiting for `master_link_status: up`
on the replica before the INCR.
2. The repl-ping-replica-period is still high (1 second), so there's a chance the
master will send an additional PING between the two calls to INFO (the line that
fails is the one that samples INFO from both servers). So there's a chance one of
them will have an incremented offset due to PING and the other won't have it yet.
In theory we can wait for the repl_offset to match, but then we risk facing a
situation where that race will hide an offset mis-match. so instead, i think we
should just change repl-ping-replica-period to prevent further pings from being pushed.
Co-authored-by: Oran Agra <oran@redislabs.com>
Add timestamp annotation in AOF, one part of #9325.
Enabled with the new `aof-timestamp-enabled` config option.
Timestamp annotation format is "#TS:${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.
in the past few days i've seen two failures in the valgrind daily test.
*** [err]: slave fails full sync and diskless load swapdb recovers it in tests/integration/replication.tcl
Replica didn't get into loading mode
can't reproduce it, but i'm hoping it's just too slow (to start loading within 5 seconds)
Since we measure the COW size in this test by changing some keys and reading
the reported COW size, we need to ensure that the "dismiss mechanism" (#8974)
will not free memory and reduce the COW size.
For that, this commit changes the size of the keys to 512B (less than a page).
and because some keys may fall into the same page, we are modifying ten keys
on each iteration and check for at least 50% change in the COW size.
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
```
- Add `-u <uri>` command line option to support `redis://` URI scheme.
- included server connection information object (`struct cliConnInfo`),
used to describe an ip:port pair, db num user input, and user:pass to
avoid a large number of function arguments.
- Using sds on connection info strings for redis-benchmark/redis-cli
Co-authored-by: yoav-steinberg <yoav@monfort.co.il>
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.
Part two of implementing #8702 (zset), after #8887.
## Description of the feature
Replaced all uses of ziplist with listpack in t_zset, and optimized some of the code to optimize performance.
## Rdb format changes
New `RDB_TYPE_ZSET_LISTPACK` rdb type.
## Rdb loading improvements:
1) Pre-expansion of dict for validation of duplicate data for listpack and ziplist.
2) Simplifying the release of empty key objects when RDB loading.
3) Unify ziplist and listpack data verify methods for zset and hash, and move code to rdb.c.
## Interface changes
1) New `zset-max-listpack-entries` config is an alias for `zset-max-ziplist-entries` (same with `zset-max-listpack-value`).
2) OBJECT ENCODING will return listpack instead of ziplist.
## Listpack improvements:
1) Add `lpDeleteRange` and `lpDeleteRangeWithEntry` functions to delete a range of entries from listpack.
2) Improve the performance of `lpCompare`, converting from string to integer is faster than converting from integer to string.
3) Replace `snprintf` with `ll2string` to improve performance in converting numbers to strings in `lpGet()`.
## Zset improvements:
1) Improve the performance of `zzlFind` method, use `lpFind` instead of `lpCompare` in a loop.
2) Use `lpDeleteRangeWithEntry` instead of `lpDelete` twice to delete a element of zset.
## Tests
1) Add some unittests for `lpDeleteRange` and `lpDeleteRangeWithEntry` function.
2) Add zset RDB loading test.
3) Add benchmark test for `lpCompare` and `ziplsitCompare`.
4) Add empty listpack zset corrupt dump test.
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
* Delay to discard cache master when full synchronization
* Don't disconnect with replicas before loading transferred RDB when full sync
Previously, once replica need to start full synchronization with master,
it will discard cached master whatever full synchronization is failed or
not.
Now we discard cached master only when transferring RDB is finished
and start to change data space, this make replica could start partial
resynchronization with another new master if new master is failed
during full synchronization.
Until now, giving a negative index seeks from the end of a list and a
positive seeks from the beginning. This change makes it seek from
the nearest end, regardless of the sign of the given index.
quicklistIndex is used by all list commands which operate by index.
LINDEX key 999999 in a list if 1M elements is greately optimized by
this change. Latency is cut by 75%.
LINDEX key -1000000 in a list of 1M elements, likewise.
LRANGE key -1 -1 is affected by this, since LRANGE converts the
indices to positive numbers before seeking.
The tests for corrupt dumps are updated to make sure the corrup
data is seeked in the same direction as before.
1. The output of --help:
* On the Usage line, just write [OPTIONS] [COMMAND ARGS...] instead listing
only a few arbitrary options and no command.
* For --cluster, describe that if the command is supplied on the command line,
the key must contain "{tag}". Otherwise, the command will not be sent to the
right cluster node.
* For -r, add a note that if -r is omitted, all commands in a benchmark will
use the same key. Also align the description.
* For -t, describe that -t is ignored if a command is supplied on the command
line.
2. Print a warning if -t is present when a specific command is supplied.
3. Print all warnings and errors to stderr.
4. Remove -e from calls in redis-benchmark test suite.
We only run OOM related tests on x86_64 and aarch64, as jemalloc on other
platforms (notably s390x) may actually succeed very large allocations. As
a result the test may hang for a very long time at the cleanup phase,
iterating as many as 2^61 hash table slots.
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>
This commit mainly fixes empty keys due to RDB loading and restore command,
which was omitted in #9297.
1) When loading quicklsit, if all the ziplists in the quicklist are empty, NULL will be returned.
If only some of the ziplists are empty, then we will skip the empty ziplists silently.
2) When loading hash zipmap, if zipmap is empty, sanitization check will fail.
3) When loading hash ziplist, if ziplist is empty, NULL will be returned.
4) Add RDB loading test with sanitize.
Replication client no longer checks incoming command length against the client-query-buffer-limit. This makes the master able to replicate commands longer than replica's configured client-query-buffer-limit
The execution of the RPOPLPUSH command by the fuzzer created junk keys,
that were later being selected by RANDOMKEY and modified.
This also meant that lists were statistically tested more than other
files.
Fix the fuzzer not to pass junk key names to RPOPLPUSH, and add a check
that detects that new keys are not added by the fuzzer to detect future
similar issues.
Recently we found two issues in the fuzzer tester: #9302#9285
After fixing them, more problems surfaced and this PR (as well as #9297) aims to fix them.
Here's a list of the fixes
- Prevent an overflow when allocating a dict hashtable
- Prevent OOM when attempting to allocate a huge string
- Prevent a few invalid accesses in listpack
- Improve sanitization of listpack first entry
- Validate integrity of stream consumer groups PEL
- Validate integrity of stream listpack entry IDs
- Validate ziplist tail followed by extra data which start with 0xff
Co-authored-by: sundb <sundbcn@gmail.com>
When we load rdb or restore command, if we encounter a length of 0, it will result in the creation of an empty key.
This could either be a corrupt payload, or a result of a bug (see #8453 )
This PR mainly fixes the following:
1) When restore command will return `Bad data format` error.
2) When loading RDB, we will silently discard the key.
Co-authored-by: Oran Agra <oran@redislabs.com>
The psync2 test has failed several times recently.
In #9159 we only solved half of the problem.
i.e. reordering of the replica that's already connected to
the newly promoted master.
Consider this scenario:
0 slaveof 2
1 slaveof 2
3 slaveof 2
4 slaveof 1
0 slaveof no one, became a new master got a new replid
2 slaveof 0, partial resync and got the new replid
3 reconnect 2, inherit the new replid
3 slaveof 4, use the new replid and got a full resync
And another scenario:
1 slaveof 3
2 slaveof 4
3 slaveof 0
4 slaveof 0
4 slaveof no one, became a new master got a new replid
2 reconnect 4, inherit the new replid
2 slaveof 1, use the new replid and got a full resync
So maybe we should reattach replicas in the right order.
i.e. In the above example, if it would have reattached 1, 3 and 0 to
the new chain formed by 4 before trying to attach 2 to 1, it would succeed.
This commit break the SLAVEOF loop into two loops. (ideas from oran)
First loop that uses random to decide who replicates from who.
Second loop that does the actual SLAVEOF command.
In the second loop, we make sure to execute it in the right order,
and after each SLAVEOF, wait for it to be connected before we proceed.
Co-authored-by: Oran Agra <oran@redislabs.com>
## 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>
When redis-cli received ASK, it used string matching wrong and didn't
handle it.
When we access a slot which is in migrating state, it maybe
return ASK. After redirect to the new node, we need send ASKING
command before retry the command. In this PR after redis-cli receives
ASK, we send a ASKING command before send the origin command
after reconnecting.
Other changes:
* Make redis-cli -u and -c (unix socket and cluster mode) incompatible
with one another.
* When send command fails, we avoid the 2nd reconnect retry and just
print the error info. Users will decide how to do next.
See #9277.
* Add a test faking two redis nodes in TCL to just send ASK and OK in
redis protocol to test ASK behavior.
Co-authored-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
Co-authored-by: Oran Agra <oran@redislabs.com>
In some cases large replies on slow systems may only be partially read
by the test suite, resulting with parsing errors.
This fix is still timing sensitive but should greatly reduce the chances
of this happening.
1. redis-cli can output --rdb data to stdout
but redis-cli also write some messages to stdout which will mess up the rdb.
2. Make redis-cli flush stdout when printing a reply
This was needed in order to fix a hung in redis-cli test that uses
--replica.
Note that printf does flush when there's a newline, but fwrite does not.
3. fix the redis-cli --replica test which used to pass previously
because it didn't really care what it read, and because redis-cli
used printf to print these other things to stdout.
4. improve redis-cli --replica test to run with both diskless and disk-based.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Viktor Söderqvist <viktor@zuiderkwast.se>
*** [err]: PSYNC2: total sum of full synchronizations is exactly 4 intests/integration/psync2.tcl
Expected 5 == 4 (context: type eval line 8 cmd {assert {$sum == 4}} proc::test)
Sometime the test got an unexpected full sync since a replica switch to master,
before the new master change propagated the new replid to all replicas,
a replica attempted to sync with it using a wrong replid and triggered a full resync.
Consider this scenario:
1 slaveof 4 full resync
0 slaveof 4 full resync
2 slaveof 0 full resync
3 slaveof 1 full resync
1 slaveof no one, replid changed
3 reconnect 1, did a partial resyn and got the new replid
Before 2 inherits the new replid.
3 slaveof 2
3 try to do a partial resyn with 2.
But their replication ids are inconsistent, so a full resync happens.
:) A special thank you for oran and helping me in this test case.
Co-authored-by: Oran Agra <oran@redislabs.com>
# replication-3.tcl
had a test timeout failure with valgrind on daily CI:
```
*** [err]: SLAVE can reload "lua" AUX RDB fields of duplicated scripts in tests/integration/replication-3.tcl
Replication not started.
```
replication took more than 70 seconds.
https://github.com/redis/redis/runs/2854037905?check_suite_focus=true
on my machine it takes only about 30, but i can see how 50 seconds isn't enough.
# replication.tcl
loading was over too quickly in freebsd daily CI:
```
*** [err]: slave fails full sync and diskless load swapdb recovers it in tests/integration/replication.tcl
Expected '0' to be equal to '1' (context: type eval line 44 cmd {assert_equal [s -1 loading] 1} proc ::start_server)
```
# rdb.tcl
loading was over too quickly.
increase the time loading takes, and decrease the amount of work we try to achieve in that time.
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`
This commit revives the improves the ability to run the test suite against
external servers, instead of launching and managing `redis-server` processes as
part of the test fixture.
This capability existed in the past, using the `--host` and `--port` options.
However, it was quite limited and mostly useful when running a specific tests.
Attempting to run larger chunks of the test suite experienced many issues:
* Many tests depend on being able to start and control `redis-server` themselves,
and there's no clear distinction between external server compatible and other
tests.
* Cluster mode is not supported (resulting with `CROSSSLOT` errors).
This PR cleans up many things and makes it possible to run the entire test suite
against an external server. It also provides more fine grained controls to
handle cases where the external server supports a subset of the Redis commands,
limited number of databases, cluster mode, etc.
The tests directory now contains a `README.md` file that describes how this
works.
This commit also includes additional cleanups and fixes:
* Tests can now be tagged.
* Tag-based selection is now unified across `start_server`, `tags` and `test`.
* More information is provided about skipped or ignored tests.
* Repeated patterns in tests have been extracted to common procedures, both at a
global level and on a per-test file basis.
* Cleaned up some cases where test setup was based on a previous test executing
(a major anti-pattern that repeats itself in many places).
* Cleaned up some cases where test teardown was not part of a test (in the
future we should have dedicated teardown code that executes even when tests
fail).
* Fixed some tests that were flaky running on external servers.
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.
In diskless replication, we create a read pipe for the RDB, between the child and the parent.
When we close this pipe (fd), the read handler also needs to be removed from the event loop (if it still registered).
Otherwise, next time we will use the same fd, the registration will be fail (panic), because
we will use EPOLL_CTL_MOD (the fd still register in the event loop), on fd that already removed from epoll_ctl
When test stop 'load handler' by killing the process that generating the load,
some commands that already in the input buffer, still might be processed by the server.
This may cause some instability in tests, that count on that no more commands
processed after we stop the `load handler'
In this commit, new proc 'wait_load_handlers_disconnected' added, to verify that no more
cammands from any 'load handler' prossesed, by checking that the clients who
genreate the load is disconnceted.
Also, replacing check of dbsize with wait_for_ofs_sync before comparing debug digest, as
it would fail in case the last key the workload wrote was an overridden key (not a new one).
Affected tests
Race fix:
- failover command to specific replica works
- Connect multiple replicas at the same time (issue #141), master diskless=$mdl, replica diskless=$sdl
- AOF rewrite during write load: RDB preamble=$rdbpre
Cleanup and speedup:
- Test replication with blocking lists and sorted sets operations
- Test replication with parallel clients writing in different DBs
- Test replication partial resync: $descr (diskless: $mdl, $sdl, reconnect: $reconnect
In github actions CI with valgrind, i saw that even the fast replica
(one that wasn't paused), didn't get to complete the replication fast
enough, and ended up getting disconnected by timeout.
Additionally, due to a typo in uname, we didn't get to actually run the
CPU efficiency part of the test.
Starting redis 6.0 (part of the TLS feature), diskless master uses pipe from the fork
child so that the parent is the one sending data to the replicas.
This mechanism has an issue in which a hung replica will cause the master to wait
for it to read the data sent to it forever, thus preventing the fork child from terminating
and preventing the creations of any other forks.
This PR adds a timeout mechanism, much like the ACK-based timeout,
we disconnect replicas that aren't reading the RDB file fast enough.
Another test race condition in the macos tests.
the test was waiting for PINGs to be generated and put on the replication stream,
but waiting for 1 or 2 seconds doesn't really guarantee that.
then the test that expected 6 full syncs, found only 4
the corrupt-dump-fuzzer test found a case where an access to a corrupt
stream would have caused accessing to uninitialized memory.
now it'll panic instead.
The issue was that there was a stream that says it has more than 0
records, but looking for the max ID came back empty handed.
p.s. when sanitize-dump-payload is used, this corruption is detected,
and the RESTORE command is gracefully rejected.
Since redis 6.2, redis immediately tries to connect to the master, not
waiting for replication cron.
in the slow freebsd CI, this test failed and master_link_status was
already "up" when INFO was called.
* The `redis-cli --scan` output should honor output mode (set explicitly or implicitly), and quote key names when not in raw mode.
* Technically this is a breaking change, but it should be very minor since raw mode is by default on for non-tty output.
* It should only affect TTY output (human users) or non-tty output if `--no-raw` is specified.
* Added `--quoted-input` option to treat all arguments as potentially quoted strings.
* Added `--quoted-pattern` option to accept a potentially quoted pattern.
Unquoting is applied to potentially quoted input only if single or double quotes are used.
Fixes#8561, #8563
When sanitizing the stream listpack, we need to count the deleted records too.
otherwise the last line that checks the next pointer fails.
Add test to cover that state in the stream tests.
* Remove linux/version.h dependency.
This introduces unnecessary dependencies, and generally not a good idea
as the platform we build on may be different than the platform we run
on.
To determine if sync_file_range exists we can simply rely on header file
hints.
* Fix setproctitle() on libmusl.
The previous ifdef checks were a bit too strict for no apparent
reason.
* Fix tests failure on Linux with no backtrace.
* Add alpine daily CI job.
* 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.
* Add bash temporarily to allow sentinel fd leaks test to run.
* Use vmactions-freebsd rdist sync to work around bind permission denied
and slow execution issues.
* Upgrade to tcl8.6 to be aligned with latest Ubuntu envs.
* Concat all command executions to avoid ignoring failures.
* Skip intensive fuzzer on FreeBSD. For some yet unknown reason, generate_fuzzy_traffic_on_key causes TCL to significantly bloat on FreeBSD resulting with out of memory.
* The corrupt dump fuzzer found a division by zero.
* in some cases the random fields from the HRANDFIELD tests produced
fields with newlines and other special chars (due to \ char), this caused
the TCL tests to see a bulk response that has a newline in it and add {}
around it, later it can think this is a nested list. in fact the `alpha` random
string generator isn't using spaces and newlines, so it should not use `\`
either.
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 adds basic coverage to IO threads by running the cluster and few selected Redis test suite tests with the IO threads enabled.
Also provides some necessary additional improvements to the test suite:
* Add --config to sentinel/cluster tests for arbitrary configuration.
* Fix --tags whitelisting which was broken.
* Add a `network` tag to some tests that are more network intensive. This is work in progress and more tests should be properly tagged in the future.
- the last COW report wasn't always read from the pipe
(receiveLastChildInfo wasn't used)
- but in fact, there's no reason we won't always try to drain that pipe
so i'm unifying receiveLastChildInfo with receiveChildInfo
- adjust threshold of the COW test when run in accurate mode
- add some prints in case this test fails again
- fix indentation, page size, and PID! in MacOS proc info
p.s. it seems that pri_pages_dirtied is always 0
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
If RESTORE passes successfully with full sanitization, we can't affort
to crash later on assertion due to duplicate records in a hash when
converting it form ziplist to dict.
This means that when doing full sanitization, we must make sure there
are no duplicate records in any of the collections.
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
- improve stream rdb encoding test to include more types of stream metadata
- add test to cover various ziplist encoding entries (although it does
look like the stress test above it is able to find some too
- add another test for ziplist encoding for hash with full sanitization
- add similar ziplist encoding tests for list
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.
As described in redis-benchamrk help message 'The test names are the same as the ones produced as output.', In redis-benchmark output, we can only see PING_BULK, but the cmd `redis-benchmark -t ping_bulk` is not supported. We have to run it with ping_mbulk which is not user friendly.
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.
- add test suite coverage for redis-benchmark
- add --version (similar to what redis-cli has)
- fix bug sending more requests than intended when pipeline > 1.
- when done sending requests, avoid freeing client in the write handler, in theory before
responses are received (probably dead code since the read handler will call clientDone first)
Co-authored-by: Oran Agra <oran@redislabs.com>
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>
When all replicas waiting for a bgsave get disconnected (possibly due to output buffer limit),
It may be good to kill the bgsave child. in diskless replication it already happens, but in
disk-based, the child may still serve some purpose (for persistence).
By killing the child, we prevent it from eating COW memory in vain, and we also allow a new child fork sooner for the next full synchronization or bgsave.
We do that only if rdb persistence wasn't enabled in the configuration.
Btw, now, rdbRemoveTempFile in killRDBChild won't block server, so we can killRDBChild safely.
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.
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.
- the test now waits for specific set of log messages rather than wait for
timeout looking for just one message.
- we don't wanna sample the current length of the log after an action, due
to a race, we need to start the search from the line number of the last
message we where waiting for.
- when attempting to trigger a full sync, use multi-exec to avoid a race
where the replica manages to re-connect before we completed the set of
actions that should force a full sync.
- fix verify_log_message which was broken and unused
on ci.redis.io the test fails a lot, reporting that bgsave didn't end.
increaseing the timeout we wait for that bgsave to get aborted.
in addition to that, i also verify that it indeed got aborted by
checking that the save counter wasn't reset.
add another test to verify that a successful bgsave indeed resets the
change counter.
This re-implements the redis-cli --pipe test so it no longer depends on a close feature available only in TCL 8.6.
Basically what this test does is run redis-cli --pipe, generates a bunch of commands and pipes them through redis-cli, and inspects the result in both Redis and the redis-cli output.
To do that, we need to close stdin for redis-cli to indicate we're done so it can flush its buffers and exit. TCL has bi-directional channels can only offers a way to "one-way close" a channel with TCL 8.6. To work around that, we now generate the commands into a file and feed that file to redis-cli directly.
As we're writing to an actual file, the number of commands is now reduced.
interestingly the latency monitor test fails because valgrind is slow
enough so that the time inside PEXPIREAT command from the moment of
the first mstime() call to get the basetime until checkAlreadyExpired
calls mstime() again is more than 1ms, and that test was too sensitive.
using this opportunity to speed up the test (unrelated to the failure)
the fix is just the longer time passed to PEXPIRE.
* Tests: fix and reintroduce redis-cli tests.
These tests have been broken and disabled for 10 years now!
* TLS: add remaining redis-cli support.
This adds support for the redis-cli --pipe, --rdb and --replica options
previously unsupported in --tls mode.
* Fix writeConn().
tests were sensitive to additional log lines appearing in the log
causing the search to come empty handed.
instead of just looking for the n last log lines, capture the log lines
before performing the action, and then search from that offset.
* tests/valgrind: don't use debug restart
DEBUG REATART causes two issues:
1. it uses execve which replaces the original process and valgrind doesn't
have a chance to check for errors, so leaks go unreported.
2. valgrind report invalid calls to close() which we're unable to resolve.
So now the tests use restart_server mechanism in the tests, that terminates
the old server and starts a new one, new PID, but same stdout, stderr.
since the stderr can contain two or more valgrind report, it is not enough
to just check for the absence of leaks, we also need to check for some known
errors, we do both, and fail if we either find an error, or can't find a
report saying there are no leaks.
other changes:
- when killing a server that was already terminated we check for leaks too.
- adding DEBUG LEAK which was used to test it.
- adding --trace-children to valgrind, although no longer needed.
- since the stdout contains two or more runs, we need slightly different way
of checking if the new process is up (explicitly looking for the new PID)
- move the code that handles --wait-server to happen earlier (before
watching the startup message in the log), and serve the restarted server too.
* squashme - CR fixes
these tests create several edge cases that are otherwise uncovered (at
least not consistently) by the test suite, so although they're no longer
testing what they were meant to test, it's still a good idea to keep
them in hope that they'll expose some issue in the future.
with the original version of 6.0.0, this test detects an excessive full
sync.
with the fix in 1a7cd2c0e, this test detects memory corruption,
especially when using libc allocator with or without valgrind.
this test which has coverage for varoius flows of diskless master was
failing randomly from time to time.
the failure was:
[err]: diskless all replicas drop during rdb pipe in tests/integration/replication.tcl
log message of '*Diskless rdb transfer, last replica dropped, killing fork child*' not found
what seemed to have happened is that the master didn't detect that all
replicas dropped by the time the replication ended, it thought that one
replica is still connected.
now the test takes a few seconds longer but it seems stable.
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
* fix memlry leaks with diskless replica short read.
* fix a few timing issues with valgrind runs
* fix issue with valgrind and watchdog schedule signal
about the valgrind WD issue:
the stack trace test in logging.tcl, has issues with valgrind:
==28808== Can't extend stack to 0x1ffeffdb38 during signal delivery for thread 1:
==28808== too small or bad protection modes
it seems to be some valgrind bug with SA_ONSTACK.
SA_ONSTACK seems unneeded since WD is not recursive (SA_NODEFER was removed),
also, not sure if it's even valid without a call to sigaltstack()
Now both master and replicas keep track of the last replication offset
that contains meaningful data (ignoring the tailing pings), and both
trim that tail from the replication backlog, and the offset with which
they try to use for psync.
the implication is that if someone missed some pings, or even have
excessive pings that the promoted replica has, it'll still be able to
psync (avoid full sync).
the downside (which was already committed) is that replicas running old
code may fail to psync, since the promoted replica trims pings form it's
backlog.
This commit adds a test that reproduces several cases of promotions and
demotions with stale and non-stale pings
Background:
The mearningful offset on the master was added recently to solve a problem were
the master is left all alone, injecting PINGs into it's backlog when no one is
listening and then gets demoted and tries to replicate from a replica that didn't
have any of the PINGs (or at least not the last ones).
however, consider this case:
master A has two replicas (B and C) replicating directly from it.
there's no traffic at all, and also no network issues, just many pings in the
tail of the backlog. now B gets promoted, A becomes a replica of B, and C
remains a replica of A. when A gets demoted, it trims the pings from its
backlog, and successfully replicate from B. however, C is still aware of
these PINGs, when it'll disconnect and re-connect to A, it'll ask for something
that's not in the backlog anymore (since A trimmed the tail of it's backlog),
and be forced to do a full sync (something it didn't have to do before the
meaningful offset fix).
Besides that, the psync2 test was always failing randomly here and there, it
turns out the reason were PINGs. Investigating it shows the following scenario:
cycle 1: redis #1 is master, and all the rest are direct replicas of #1
cycle 2: redis #2 is promoted to master, #1 is a replica of #2 and #3 is replica of #1
now we see that when #1 is demoted it prints:
17339:S 21 Apr 2020 11:16:38.523 * Using the meaningful offset 3929963 instead of 3929977 to exclude the final PINGs (14 bytes difference)
17339:S 21 Apr 2020 11:16:39.391 * Trying a partial resynchronization (request e2b3f8817735fdfe5fa4626766daa938b61419e5:3929964).
17339:S 21 Apr 2020 11:16:39.392 * Successful partial resynchronization with master.
and when #3 connects to the demoted #2, #2 says:
17339:S 21 Apr 2020 11:16:40.084 * Partial resynchronization not accepted: Requested offset for secondary ID was 3929978, but I can reply up to 3929964
so the issue here is that the meaningful offset feature saved the day for the
demoted master (since it needs to sync from a replica that didn't get the last
ping), but it didn't help one of the other replicas which did get the last ping.
Meir Shpilraien (Spielrein)