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Fix multiple formatting problems in HTML docs The rule generating the HTML docs passing the --html flag to xsltproc. This makes it use the legacy HTML parser, which either ignores or tries to fix all sorts of broken XML tags. There's no reason why we should be writing broken XML in the first place, so removing --html and adding the XHTML doctype to all files forces us to create good XML. This adds the XHTML doc type and fixes many, many XML tag problems it exposes. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-03 22:25:37 +08:00
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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<body>
<h1 >Logging in the library and the daemon</h1>
Auto-generate the table of contents in logging doc The logging doc had a hand-written table of contents instead of using the automatic XSL generated one. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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<p>Libvirt includes logging facilities starting from version 0.6.0,
this complements the <a href="errors.html">error handling</a>
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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mechanism and APIs to allow tracing through the execution of the
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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library as well as in the libvirtd daemon.</p>
Auto-generate the table of contents in logging doc The logging doc had a hand-written table of contents instead of using the automatic XSL generated one. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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<ul id="toc"/>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
<h2>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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<a name="log_library">Logging in the library</a>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
</h2>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
2008-12-23 21:47:10 +08:00
<p>The logging functionalities in libvirt are based on 3 key concepts,
similar to the one present in other generic logging facilities like
log4j:</p>
<ul>
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<li><b>log messages</b>: they are information generated at runtime by
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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the libvirt code. Each message includes a priority level (DEBUG = 1,
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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INFO = 2, WARNING = 3, ERROR = 4), a category, function name and
line number, indicating where it originated from, and finally
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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a formatted message. In addition the library adds a timestamp
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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at the beginning of the message</li>
<li><b>log filters</b>: a set of patterns and priorities to accept
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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or reject a log message. If the message category matches a filter,
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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the message priority is compared to the filter priority, if lower
the message is discarded, if higher the message is output. If
no filter matches, then a general priority level is applied to
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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all remaining messages. This allows, for example, capturing all
debug messages for the QEmu driver, but otherwise only allowing
errors to show up from other parts.</li>
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<li><b>log outputs</b>: once a message has gone through filtering a set of
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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output defines where to send the message, they can also filter
based on the priority, for example it may be useful to output
all messages to a debugging file but only allow errors to be
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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logged through syslog.</li>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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</ul>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
<h2>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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<a name="log_config">Configuring logging in the library</a>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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</h2>
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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<p>The library configuration of logging is through 3 environment variables
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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allowing to control the logging behaviour:</p>
<ul>
<li>LIBVIRT_DEBUG: it can take the four following values:
<ul>
<li>1 or "debug": asking the library to log every message emitted,
though the filters can be used to avoid filling up the output</li>
docs: fix some typos about 'informations' s/informations/information Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-10-22 11:02:43 +08:00
<li>2 or "info": log all non-debugging information</li>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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<li>3 or "warn": log warnings and errors, that's the default value</li>
<li>4 or "error": log only error messages</li>
</ul></li>
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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<li>LIBVIRT_LOG_FILTERS: defines logging filters</li>
<li>LIBVIRT_LOG_OUTPUTS: defines logging outputs</li>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
2008-12-23 21:47:10 +08:00
</ul>
Update logging documentation * docs/logging.html[.in] try to include a little more description about the corner cases, things someone might get hung up on on.
2009-08-06 21:58:38 +08:00
<p>Note that, for example, setting LIBVIRT_DEBUG= is the same as unset. If
you specify an invalid value, it will be ignored with a warning. If you
have an error in a filter or output string, some of the settings may be
applied up to the point at which libvirt encountered the error.</p>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
<h2>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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<a name="log_daemon">Logging in the daemon</a>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
</h2>
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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<p>Similarly the daemon logging behaviour can be tuned using 3 config
docs: correct invalid xml * docs/internals.html.in: Fix xml errors. * docs/formatstorageencryption.html.in: Likewise. * docs/drvesx.html.in: Likewise. * docs/archnetwork.html.in: Likewise. * docs/logging.html.in: Likewise. * docs/drvvmware.html.in: Likewise. * docs/api.html.in: Likewise. * docs/formatnwfilter.html.in: Likewise. * docs/formatdomain.html.in: Likewise. * docs/windows.html.in: Likewise.
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variables, stored in the configuration file:</p>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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<ul>
<li>log_level: accepts the following values:
<ul>
<li>4: only errors</li>
<li>3: warnings and errors</li>
docs: fix some typos about 'informations' s/informations/information Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-10-22 11:02:43 +08:00
<li>2: information, warnings and errors</li>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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<li>1: debug and everything</li>
</ul></li>
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
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<li>log_filters: defines logging filters</li>
<li>log_outputs: defines logging outputs</li>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
2008-12-23 21:47:10 +08:00
</ul>
Update logging documentation * docs/logging.html[.in] try to include a little more description about the corner cases, things someone might get hung up on on.
2009-08-06 21:58:38 +08:00
<p>When starting the libvirt daemon, any logging environment variable
settings will override settings in the config file. Command line options
take precedence over all. If no outputs are defined for libvirtd, it
Add docs about use of systemd journal for logging Document the various fields that libvirt will emit for journal log records. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:22:51 +08:00
will try to use</p>
<ul>
<li>0.10.0 or later: systemd journal, if <code>/run/systemd/journal/socket</code> exists</li>
<li>0.9.0 or later: file <code>/var/log/libvirt/libvirtd.log</code> if running as a daemon</li>
<li>before 0.9.0: syslog if running as a daemon</li>
<li>all versions: to stderr stream if running in the foreground</li>
</ul>
Update logging documentation * docs/logging.html[.in] try to include a little more description about the corner cases, things someone might get hung up on on.
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<p>Libvirtd does not reload its logging configuration when issued a SIGHUP.
If you want to reload the configuration, you must do a <code>service
libvirtd restart</code> or manually stop and restart the daemon
yourself.</p>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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<p>Starting from 0.9.0, the daemon can save all the content of the debug
buffer to the defined error channels (or /var/log/libvirt/libvirtd.log
by default) in case of crash, this can also be activated explicitly
for debugging purposes by sending the daemon a USR2 signal:</p>
<pre>killall -USR2 libvirtd</pre>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
<h2>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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<a name="log_syntax">Syntax for filters and output values</a>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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</h2>
Update logging documentation * docs/logging.html[.in] try to include a little more description about the corner cases, things someone might get hung up on on.
2009-08-06 21:58:38 +08:00
<p>The syntax for filters and outputs is the same for both types of
variables.</p>
Allow stack traces to be included with log messages Sometimes it is useful to see the callpath for log messages. This change enhances the log filter syntax so that stack traces can be show by setting '1:+NAME' instead of '1:NAME'. This results in output like: 2012-05-09 14:18:45.136+0000: 13314: debug : virInitialize:414 : register drivers /home/berrange/src/virt/libvirt/src/.libs/libvirt.so.0(virInitialize+0xd6)[0x7f89188ebe86] /home/berrange/src/virt/libvirt/tools/.libs/lt-virsh[0x431921] /lib64/libc.so.6(__libc_start_main+0xf5)[0x3a21e21735] /home/berrange/src/virt/libvirt/tools/.libs/lt-virsh[0x40a279] 2012-05-09 14:18:45.136+0000: 13314: debug : virRegisterDriver:775 : driver=0x7f8918d02760 name=Test /home/berrange/src/virt/libvirt/src/.libs/libvirt.so.0(virRegisterDriver+0x6b)[0x7f89188ec717] /home/berrange/src/virt/libvirt/src/.libs/libvirt.so.0(+0x11b3ad)[0x7f891891e3ad] /home/berrange/src/virt/libvirt/src/.libs/libvirt.so.0(virInitialize+0xf3)[0x7f89188ebea3] /home/berrange/src/virt/libvirt/tools/.libs/lt-virsh[0x431921] /lib64/libc.so.6(__libc_start_main+0xf5)[0x3a21e21735] /home/berrange/src/virt/libvirt/tools/.libs/lt-virsh[0x40a279] * docs/logging.html.in: Document new syntax * configure.ac: Check for execinfo.h * src/util/logging.c, src/util/logging.h: Add support for stack traces * tests/testutils.c: Adapt to API change Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-05-09 22:18:56 +08:00
<p>The format for a filter is one of:</p>
<pre>
logging.html.in: Kill useless spaces in <pre/> The <pre/> section is rendered as-is on the page. That is, if all the lines are prefixed with 4 spaces the rendered page will also have them. Problem is if we put a box around such <pre/> because the content might not fix into it. Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-11-12 06:40:27 +08:00
x:name (log message only)
x:+name (log message + stack trace)</pre>
docs: update to properly reflect meaning of fields in log filter The documentation (and comment in libvirtd.conf) says that the text in a log filter is compared to the "source file name", and gives the example of "util/json", but this is not correct (at least not since commit 2835c1e, possibly earlier). It is instead compared to the string given in the VIR_LOG_INIT() macro invocation at the top of each source file, which is always "similar to but not the same as" the source file name (in the example above, the proper name is "util.json", while the file name is "util/virjson.c"). This patch corrects the misstatement in both the documentation and in libvirtd.conf.
2015-12-21 23:53:57 +08:00
<p>where <code>name</code> is a string which is matched against
the category given in the VIR_LOG_INIT() at the top of each
libvirt source file, e.g., <code>remote</code>, <code>qemu</code>,
or <code>util.json</code> (the name in the filter can be a
substring of the full category name, in order to match multiple
similar categories), the optional <code>+</code> prefix tells
libvirt to log stack trace for each message
matching <code>name</code>, and <code>x</code> is the minimal
level where matching messages should be logged:</p>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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<ul>
<li>1: DEBUG</li>
<li>2: INFO</li>
<li>3: WARNING</li>
<li>4: ERROR</li>
</ul>
Update logging documentation * docs/logging.html[.in] try to include a little more description about the corner cases, things someone might get hung up on on.
2009-08-06 21:58:38 +08:00
<p>Multiple filters can be defined in a single string, they just need to be
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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separated by spaces, e.g: <code>"3:remote 4:event"</code> to only get
warning or errors from the remote layer and only errors from the event
docs: correct invalid xml * docs/internals.html.in: Fix xml errors. * docs/formatstorageencryption.html.in: Likewise. * docs/drvesx.html.in: Likewise. * docs/archnetwork.html.in: Likewise. * docs/logging.html.in: Likewise. * docs/drvvmware.html.in: Likewise. * docs/api.html.in: Likewise. * docs/formatnwfilter.html.in: Likewise. * docs/formatdomain.html.in: Likewise. * docs/windows.html.in: Likewise.
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layer.</p>
Update logging documentation * docs/logging.html[.in] try to include a little more description about the corner cases, things someone might get hung up on on.
2009-08-06 21:58:38 +08:00
<p>If you specify a log priority in a filter that is below the default log
priority level, messages that match that filter will still be logged,
while others will not. In order to see those messages, you must also have
an output defined that includes the priority level of your filter.</p>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
2008-12-23 21:47:10 +08:00
<p>The format for an output can be one of those 3 forms:</p>
<ul>
<li><code>x:stderr</code> output goes to stderr</li>
<li><code>x:syslog:name</code> use syslog for the output and use the
given <code>name</code> as the ident</li>
docs: add 3 missing spaces
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<li><code>x:file:file_path</code> output to a file, with the given
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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filepath</li>
Add docs about use of systemd journal for logging Document the various fields that libvirt will emit for journal log records. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:22:51 +08:00
<li><code>x:journald</code> output goes to systemd journal</li>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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</ul>
<p>In all cases the x prefix is the minimal level, acting as a filter:</p>
<ul>
<li>1: DEBUG</li>
<li>2: INFO</li>
<li>3: WARNING</li>
<li>4: ERROR</li>
</ul>
docs: grammar cleanups on logging examples * docs/logging.html.in: Fix spelling and grammar.
2010-09-23 05:34:17 +08:00
<p>Multiple output can be defined, they just need to be separated by
Various logging cleanups in code and doc * docs/logging.html[.in] qemud/libvirtd.conf qemud/qemud.c src/logging.[ch]: cleanup the logging code and docs to remove all references to log level 0, cleanup hardcoded values and add a default VIR_LOG_DEFAULT value, patch by Amy Griffis daniel
2009-07-01 19:21:15 +08:00
spaces, e.g.: <code>"3:syslog:libvirtd 1:file:/tmp/libvirt.log"</code>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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will log all warnings and errors to syslog under the libvirtd ident
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
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but also log all debug and information included in the
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
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file <code>/tmp/libvirt.log</code></p>
Add docs about use of systemd journal for logging Document the various fields that libvirt will emit for journal log records. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:22:51 +08:00
<h2><a name="journald">Systemd journal fields</a></h2>
<p>
When logging to the systemd journal, the following fields
are defined, in addition to any automatically recorded
<a href="http://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html">standard fields</a>:
</p>
<dl>
<dt><code>MESSAGE</code></dt>
<dd>The log message string</dd>
<dt><code>PRIORITY</code></dt>
<dd>The log priority value</dd>
<dt><code>LIBVIRT_SOURCE</code></dt>
<dd>The source type, one of "file", "error", "audit", "trace", "library"</dd>
<dt><code>CODE_FILE</code></dt>
<dd>The name of the file emitting the log record</dd>
<dt><code>CODE_LINE</code></dt>
<dd>The line number of the file emitting the log record</dd>
<dt><code>CODE_FUNC</code></dt>
<dd>The name of the function emitting the log record</dd>
Include error domain and code in log messages from errors When a virError is raised, pass the error domain and code onto the systemd journald using metadata fields. This allows error messages to be queried by code eg $ journalctl LIBVIRT_CODE=43 Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-22 01:23:10 +08:00
<dt><code>LIBVIRT_DOMAIN</code></dt>
<dd>The libvirt error domain (values from virErrorDomain enum), if LIBVIRT_SOURCE="error"</dd>
<dt><code>LIBVIRT_CODE</code></dt>
<dd>The libvirt error code (values from virErrorCode enum), if LIBVIRT_SOURCE="error"</dd>
Add docs about use of systemd journal for logging Document the various fields that libvirt will emit for journal log records. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:22:51 +08:00
</dl>
Generate a unique journald log for QEMU capabilities failure When probing QEMU capabilities fails for a binary generate a log message with MESSAGE_ID==8ae2f3fb-2dbe-498e-8fbd-012d40afa361. This can be directly queried from journald based on the UUID instead of needing string grep. This lets tools like libguestfs' bug reporting tool trivially do automated sanity tests on the host they're running on. $ journalctl MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361 Feb 21 17:11:01 localhost.localdomain lt-libvirtd[9196]: Failed to probe capabilities for /bin/qemu-system-alpha: internal error: Child process (LC_ALL=C LD_LIBRARY_PATH= /home/berrange/src/virt/libvirt/src/.libs PATH=/usr/lib64/ ccache:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin: /usr/bin:/root/bin HOME=/root USER=root LOGNAME=root /bin/qemu-system-alpha -help) unexpected exit status 127: /bin/qemu-system-alpha: error while loading shared libraries: libglapi.so.0: cannot open shared object file: No such file or directory $ journalctl MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361 --output=json { ...snip... "LIBVIRT_SOURCE" : "file", "PRIORITY" : "3", "CODE_FILE" : "qemu/qemu_capabilities.c", "CODE_LINE" : "2770", "CODE_FUNC" : "virQEMUCapsLogProbeFailure", "MESSAGE_ID" : "8ae2f3fb-2dbe-498e-8fbd-012d40afa361", "LIBVIRT_QEMU_BINARY" : "/bin/qemu-system-xtensa", "MESSAGE" : "Failed to probe capabilities for /bin/qemu-system-xtensa: internal error: Child process (LC_ALL=C LD_LIBRARY_PATH=/home/berrange /src/virt/libvirt/src/.libs PATH=/usr/lib64/ccache:/usr/local/sbin: /usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin HOME=/root USER=root LOGNAME=root /bin/qemu-system-xtensa -help) unexpected exit status 127: /bin/qemu-system-xtensa: error while loading shared libraries: libglapi.so.0: cannot open shared object file: No such file or directory\n" } Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-22 01:16:07 +08:00
<h3><a name="journaldids">Well known message ID values</a></h3>
<p>
Certain areas of the code will emit log records tagged with well known
unique id values, which are guaranteed never to change in the future.
This allows applications to identify critical log events without doing
string matching on the <code>MESSAGE</code> field.
</p>
<dl>
<dt><code>MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361</code></dt>
<dd>Generated by the QEMU driver when it identifies a QEMU system
emulator binary, but is unable to extract information about its
capabilities. This is usually an indicator of a broken QEMU
build or installation. When this is emitted, the <code>LIBVIRT_QEMU_BINARY</code>
message field will provide the full path of the QEMU binary that failed.
</dd>
</dl>
<p>
The <code>journalctl</code> command can be used to search the journal
matching on specific message ID values
</p>
<pre>
logging.html.in: Kill useless spaces in <pre/> The <pre/> section is rendered as-is on the page. That is, if all the lines are prefixed with 4 spaces the rendered page will also have them. Problem is if we put a box around such <pre/> because the content might not fix into it. Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-11-12 06:40:27 +08:00
$ journalctl MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361 --output=json
{ ...snip...
"LIBVIRT_SOURCE" : "file",
"PRIORITY" : "3",
"CODE_FILE" : "qemu/qemu_capabilities.c",
"CODE_LINE" : "2770",
"CODE_FUNC" : "virQEMUCapsLogProbeFailure",
"MESSAGE_ID" : "8ae2f3fb-2dbe-498e-8fbd-012d40afa361",
"LIBVIRT_QEMU_BINARY" : "/bin/qemu-system-xtensa",
"MESSAGE" : "Failed to probe capabilities for /bin/qemu-system-xtensa:" \
"internal error: Child process (LC_ALL=C LD_LIBRARY_PATH=/home/berrange" \
"/src/virt/libvirt/src/.libs PATH=/usr/lib64/ccache:/usr/local/sbin:" \
"/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin HOME=/root " \
"USER=root LOGNAME=root /bin/qemu-system-xtensa -help) unexpected " \
"exit status 127: /bin/qemu-system-xtensa: error while loading shared " \
"libraries: libglapi.so.0: cannot open shared object file: No such " \
"file or directory\n" }
Generate a unique journald log for QEMU capabilities failure When probing QEMU capabilities fails for a binary generate a log message with MESSAGE_ID==8ae2f3fb-2dbe-498e-8fbd-012d40afa361. This can be directly queried from journald based on the UUID instead of needing string grep. This lets tools like libguestfs' bug reporting tool trivially do automated sanity tests on the host they're running on. $ journalctl MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361 Feb 21 17:11:01 localhost.localdomain lt-libvirtd[9196]: Failed to probe capabilities for /bin/qemu-system-alpha: internal error: Child process (LC_ALL=C LD_LIBRARY_PATH= /home/berrange/src/virt/libvirt/src/.libs PATH=/usr/lib64/ ccache:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin: /usr/bin:/root/bin HOME=/root USER=root LOGNAME=root /bin/qemu-system-alpha -help) unexpected exit status 127: /bin/qemu-system-alpha: error while loading shared libraries: libglapi.so.0: cannot open shared object file: No such file or directory $ journalctl MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361 --output=json { ...snip... "LIBVIRT_SOURCE" : "file", "PRIORITY" : "3", "CODE_FILE" : "qemu/qemu_capabilities.c", "CODE_LINE" : "2770", "CODE_FUNC" : "virQEMUCapsLogProbeFailure", "MESSAGE_ID" : "8ae2f3fb-2dbe-498e-8fbd-012d40afa361", "LIBVIRT_QEMU_BINARY" : "/bin/qemu-system-xtensa", "MESSAGE" : "Failed to probe capabilities for /bin/qemu-system-xtensa: internal error: Child process (LC_ALL=C LD_LIBRARY_PATH=/home/berrange /src/virt/libvirt/src/.libs PATH=/usr/lib64/ccache:/usr/local/sbin: /usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin HOME=/root USER=root LOGNAME=root /bin/qemu-system-xtensa -help) unexpected exit status 127: /bin/qemu-system-xtensa: error while loading shared libraries: libglapi.so.0: cannot open shared object file: No such file or directory\n" } Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-22 01:16:07 +08:00
</pre>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
<h2>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
2011-03-17 15:30:49 +08:00
<a name="log_examples">Examples</a>
Fix heading level in logging docs The logging docs went straight from <h1> to <h3> header level, skipping out <h2>. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-02-25 00:34:36 +08:00
</h2>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
2008-12-23 21:47:10 +08:00
<p>For example setting up the following:</p>
<pre>export LIBVIRT_DEBUG=1
Various logging cleanups in code and doc * docs/logging.html[.in] qemud/libvirtd.conf qemud/qemud.c src/logging.[ch]: cleanup the logging code and docs to remove all references to log level 0, cleanup hardcoded values and add a default VIR_LOG_DEFAULT value, patch by Amy Griffis daniel
2009-07-01 19:21:15 +08:00
export LIBVIRT_LOG_OUTPUTS="1:file:virsh.log"</pre>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
2008-12-23 21:47:10 +08:00
<p>and then running virsh will accumulate the logs in the
<code>virsh.log</code> file in a way similar to:</p>
<pre>14:29:04.771: debug : virInitialize:278 : register drivers
14:29:04.771: debug : virRegisterDriver:618 : registering Test as driver 0</pre>
<p>the messages are timestamped, there is also the level recorded,
if debug the name of the function is also printed and then the formatted
message. This should be sufficient to at least get a precise idea of
what is happening and where things are going wrong, allowing to then
put the correct breakpoints when running under a debugger.</p>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
2011-03-17 15:30:49 +08:00
<p>To activate full debug of the libvirt entry points, utility
functions and the QEmu/KVM driver, set:</p>
docs: fix usage example on setting log levels Reported by Michael S. Tsirkin. * docs/logging.html.in (log_examples): Use correct libvirtd.conf syntax.
2012-03-13 05:34:55 +08:00
<pre>log_filters="1:libvirt 1:util 1:qemu"
log_outputs="1:file:/var/log/libvirt/libvirtd.log"</pre>
Improve logging documentation including the debug buffer * docs/logging.html.in: document the fact that starting from 0.9.0 the server logs goes to libvirtd.log instead of syslog by default, describe the debug buffer, restructure the page and add a couple more examples
2011-03-17 15:30:49 +08:00
<p>in libvirtd.conf and restart the daemon will allow to
gather a copious amount of debugging traces for the operations done
in those areas.</p>
* docs/logging.html docs/logging.html.in: new page documenting the logging system * docs/auth.html docs/deployment.html docs/remote.html docs/sitemap.html docs/sitemap.html.in docs/uri.html docs/windows.html: integration in the existing set Daniel
2008-12-23 21:47:10 +08:00
</body>
</html>