Commit Graph

24 Commits

Author SHA1 Message Date
Daniel P. Berrangé
9b80e0c12a util: drop support for stack traces with logging
The log filters have supported the use of a "+" before the source match
string to request that a stack trace be emitted for every log message:

  commit 548563956e
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Wed May 9 15:18:56 2012 +0100

    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'.

With the huge & ever increasing number of logging statements per file,
this will be incredibly verbose and have a major performance penalty.
This makes the feature impractical to use widely and as such it is not
worth the code maint cost.

Removing this seldom used feature allows us to drop the 'execinfo'
module in gnulib which provides the backtrace() function which doesn't
exist on non-Linux.

Users who want to get stack traces of parts of libvirt can use GDB,
or systemtap for live tracing with minimal perf impact.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-10-18 16:25:17 +01:00
Ján Tomko
1943d89b72 Replace QEmu with QEMU
QEMU is the preferred spelling used on QEMU website.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
2018-04-01 17:42:29 +02:00
Daniel P. Berrange
b1c81567c7 docs: switch to using HTML5 doctype declaration
The HTML5 doctype is simply

  <!DOCTYPE html>

no DTD is present because HTML5 is no longer defined as an
extension of SGML.

XSL has no way to natively output a doctype without a public
or system identifier, so we have to use an <xsl:text> hack
instead.

See also

  https://dev.w3.org/html5/html-author/#doctype-declaration

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-08-02 17:00:11 +01:00
Daniel P. Berrange
4e42ff6b7e docs: switch to using 'id' attribute instead of 'name' for links
The 'name' attribute on <a...> elements is deprecated in favour
of the 'id' attribute which is allowed on any element. HTML5
drops 'name' support entirely.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-08-02 17:00:11 +01:00
Michal Privoznik
3260b7d3cc 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>
2016-11-14 11:03:34 +01:00
Laine Stump
79e7872530 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.
2016-01-04 15:19:38 -05:00
Daniel P. Berrange
c0c8c1d7bb Remove global log buffer feature entirely
A earlier commit changed the global log buffer so that it only
records messages that are explicitly requested via the log
filters setting. This removes the performance burden, and
improves the signal/noise ratio for messages in the global
buffer. At the same time though, it is somewhat pointless, since
all the recorded log messages are already going to be sent to an
explicit log output like syslog, stderr or the journal. The
global log buffer is thus just duplicating this data on stderr
upon crash.

The log_buffer_size config parameter is left in the augeas
lens to prevent breakage for users on upgrade. It is however
completely ignored hereafter.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-03-18 14:29:22 +00:00
Daniel P. Berrange
36ff4ed1ec 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>
2014-03-03 11:42:37 +00:00
Daniel P. Berrange
0915053e97 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>
2014-02-28 17:38:46 +00:00
Daniel P. Berrange
c6cae57098 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>
2014-02-28 17:38:44 +00:00
Daniel P. Berrange
a9bcd60e31 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>
2014-02-28 17:37:38 +00:00
Daniel P. Berrange
e86ee41bc1 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>
2014-02-28 17:37:38 +00:00
Chen Hanxiao
dc33207dbe docs: fix some typos about 'informations'
s/informations/information

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-10-22 09:47:19 +01:00
Daniel P. Berrange
f2f9742d4d 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 15:56:15 +01:00
Jiri Denemark
395be3c2b8 docs: Enhance documentation of log_filters
Also make sure documentation in libvirtd.conf matches the one from
logging.html.
2012-08-17 21:26:53 +02:00
Daniel P. Berrange
548563956e 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>
2012-05-15 17:01:40 +01:00
Eric Blake
98deac7dcc docs: fix usage example on setting log levels
Reported by Michael S. Tsirkin.

* docs/logging.html.in (log_examples): Use correct libvirtd.conf
syntax.
2012-03-12 15:34:55 -06:00
Eric Blake
b5ec89d955 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.
2011-04-01 16:03:11 -06:00
Daniel Veillard
08ddbe61f6 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
2011-03-18 10:06:31 +08:00
Eric Blake
50f6b66b18 docs: grammar cleanups on logging examples
* docs/logging.html.in: Fix spelling and grammar.
2010-09-23 11:14:23 -06:00
Dan Kenigsberg
d5739ab56a docs: add 3 missing spaces 2010-02-21 14:56:23 +01:00
Amy Griffis
7534be6fbc 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 15:58:38 +02:00
Daniel Veillard
2a004db6c7 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 11:21:15 +00:00
Daniel Veillard
e03a902735 * 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 13:47:10 +00:00