NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT VARIABLES | FILES | EXIT STATUS | BUGS | RESOURCES | COPYRIGHTS | THANKS | AUTHORS | SEE ALSO | COLOPHON

LTTNG-ADD-CONTEXT(1)            LTTng Manual            LTTNG-ADD-CONTEXT(1)

NAME         top

       lttng-add-context - Add context fields to an LTTng channel

SYNOPSIS         top

       Add context fields to a channel:

       lttng [GENERAL OPTIONS] add-context
             (--kernel | --userspace | --jul | --log4j)
             [--session=SESSION] [--channel=CHANNEL]
             --type=TYPE [--type=TYPE]...

       List the available context fields:

       lttng [GENERAL OPTIONS] add-context --list

DESCRIPTION         top

       The lttng add-context command adds one or more context fields to a
       channel.

       Channels are created with the lttng-enable-channel(1) command.

       When context fields are added to a channel, all the events emitted
       within this channel contain the dynamic values of those context
       fields.

       If the --session option is omitted, the current tracing session is
       used. If the --channel option is omitted, the context fields are
       added to all the selected tracing session’s channels.

       Many context fields can be added to a channel at once by repeating
       the --type option.

       perf counters are available as per-CPU (perf:cpu: prefix) as well as
       per-thread (perf:thread: prefix) counters. Currently, per-CPU
       counters can only be used in the Linux kernel tracing domain, while
       per-thread counters can only be used in the user space tracing
       domain.

       It is also possible to enable PMU counters by raw ID using the
       perf:cpu:raw:rN:NAME (Linux kernel tracing domain) or
       perf:thread:raw:rN:NAME (user space tracing domain), with:

       N
           A hexadecimal event descriptor which is the same format as used
           by perf-record(1): a concatenation of the event number and umask
           value provided by the processor’s manufacturer. The possible
           values for this field are processor-specific.

       NAME
           Custom name to easily recognize the counter.

       Application-specific context fields can be added to a channel using
       the following syntax:

           $app.PROVIDER:TYPE

       with:

       PROVIDER
           Provider name.

       TYPE
           Context type name.

           Note
           Make sure to single-quote the type when running the command from
           a shell, as $ is a special character for variable substitution in
           most shells.

       Use the --list option without other arguments to list the available
       context field names.

OPTIONS         top

       General options are described in lttng(1).

   Domain
       One of:

       -j, --jul
           Add context to channel in the java.util.logging (JUL) domain.

       -k, --kernel
           Add context to channel in the Linux kernel domain.

       -l, --log4j
           Add context to channel in the Apache log4j domain.

       -u, --userspace
           Add context to channel in the user space domain.

   Target
       -c CHANNEL, --channel=CHANNEL
           Add context fields to a channel named CHANNEL instead of adding
           them to all the channels.

       -s SESSION, --session=SESSION
           Add context fields to a channel in the tracing session named
           SESSION instead of the current tracing session.

   Context
       --list
           List the available context fields. Use this option alone.

       -t TYPE, --type=TYPE
           Add context field named TYPE. This option can be repeated as many
           times as needed on the command-line.

   Program information
       -h, --help
           Show command help.

           This option, like lttng-help(1), attempts to launch /usr/bin/man
           to view the command’s man page. The path to the man pager can be
           overridden by the LTTNG_MAN_BIN_PATH environment variable.

       --list-options
           List available command options.

ENVIRONMENT VARIABLES         top

       LTTNG_ABORT_ON_ERROR
           Set to 1 to abort the process after the first error is
           encountered.

       LTTNG_HOME
           Overrides the $HOME environment variable. Useful when the user
           running the commands has a non-writable home directory.

       LTTNG_MAN_BIN_PATH
           Absolute path to the man pager to use for viewing help
           information about LTTng commands (using lttng-help(1) or lttng
           COMMAND --help).

       LTTNG_SESSION_CONFIG_XSD_PATH
           Path in which the session.xsd session configuration XML schema
           may be found.

       LTTNG_SESSIOND_PATH
           Full session daemon binary path.

           The --sessiond-path option has precedence over this environment
           variable.

       Note that the lttng-create(1) command can spawn an LTTng session
       daemon automatically if none is running. See lttng-sessiond(8) for
       the environment variables influencing the execution of the session
       daemon.

FILES         top

       $LTTNG_HOME/.lttngrc
           User LTTng runtime configuration.

           This is where the per-user current tracing session is stored
           between executions of lttng(1). The current tracing session can
           be set with lttng-set-session(1). See lttng-create(1) for more
           information about tracing sessions.

       $LTTNG_HOME/lttng-traces
           Default output directory of LTTng traces. This can be overridden
           with the --output option of the lttng-create(1) command.

       $LTTNG_HOME/.lttng
           User LTTng runtime and configuration directory.

       $LTTNG_HOME/.lttng/sessions
           Default location of saved user tracing sessions (see
           lttng-save(1) and lttng-load(1)).

       /usr/local/etc/lttng/sessions
           System-wide location of saved tracing sessions (see lttng-save(1)
           and lttng-load(1)).

           Note
           $LTTNG_HOME defaults to $HOME when not explicitly set.

EXIT STATUS         top

       0
           Success

       1
           Command error

       2
           Undefined command

       3
           Fatal error

       4
           Command warning (something went wrong during the command)

BUGS         top

       If you encounter any issue or usability problem, please report it on
       the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-tools>.

RESOURCES         top

       ·   LTTng project website <http://lttng.org>

       ·   LTTng documentation <http://lttng.org/docs>

       ·   Git repositories <http://git.lttng.org>

       ·   GitHub organization <http://github.com/lttng>

       ·   Continuous integration <http://ci.lttng.org/>

       ·   Mailing list <http://lists.lttng.org> for support and
           development: lttng-dev@lists.lttng.org

       ·   IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net

COPYRIGHTS         top

       This program is part of the LTTng-tools project.

       LTTng-tools is distributed under the GNU General Public License
       version 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>.
       See the LICENSE <https://github.com/lttng/lttng-
       tools/blob/master/LICENSE> file for details.

THANKS         top

       Special thanks to Michel Dagenais and the DORSAL laboratory
       <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal
       for the LTTng journey.

       Also thanks to the Ericsson teams working on tracing which helped us
       greatly with detailed bug reports and unusual test cases.

AUTHORS         top

       LTTng-tools was originally written by Mathieu Desnoyers, Julien
       Desfossez, and David Goulet. More people have since contributed to
       it.

       LTTng-tools is currently maintained by Jérémie Galarneau
       <mailto:jeremie.galarneau@efficios.com>.

SEE ALSO         top

       lttng(1)

COLOPHON         top

       This page is part of the LTTng-Tools (    LTTng tools) project.
       Information about the project can be found at ⟨http://lttng.org/⟩.
       It is not known how to report bugs for this man page; if you know,
       please send a mail to man-pages@man7.org.  This page was obtained
       from the project's upstream Git repository 
       ⟨git://git.lttng.org/lttng-tools.git⟩ on 2017-04-25.  If you discover
       any rendering problems in this HTML version of the page, or you
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       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

LTTng 2.10.0-pre                 04/25/2017             LTTNG-ADD-CONTEXT(1)

Pages that refer to this page: lttng(1)lttng-enable-event(1)lttng-ust(3)