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>
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>
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>
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>
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.
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>
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>
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>
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>
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>
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>
* 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
* 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
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
