lttng-stop

Synopsis

lttng [GENERAL OPTIONS] stop [--no-wait] [SESSION]

Description

The lttng stop command stops the various LTTng tracers for a given active tracing session.

Stopping the LTTng tracers has the effect that all enabled event rules within enabled channels cannot make event sources emit trace events anymore.

A tracing session with no running tracers is said to be inactive. Inactive tracing sessions can be set active using the lttng-start(1) command.

If SESSION is omitted, the LTTng tracers are stopped for the current tracing session (see lttng-create(1) for more information about the current tracing session). Otherwise, they are stopped for the existing tracing session named SESSION. lttng list outputs all the existing tracing sessions (see lttng-list(1)).

By default, the lttng stop command ensures that the tracing session’s trace data is valid before returning to the prompt. With the --no-wait option, the command finishes immediately, hence a local trace might not be valid when the command is done. In this case, there is no way to know when the trace becomes valid.

If at least one rotation occurred during the chosen tracing session’s lifetime (see lttng-rotate(1) and lttng-enable-rotation(1)), the lttng stop command renames the current trace chunk subdirectory and prints the renamed path. Although it is safe to read the content of this renamed subdirectory while the tracing session remains inactive (until the next lttng-start(1)), it is NOT a trace chunk archive: you need to destroy the tracing session with lttng-destroy(1) or make a rotation with lttng-rotate(1) to archive it.

Options

General options are described in lttng(1).

-n, --no-wait

Do not ensure that the chosen tracing session’s trace data is valid before returning to the prompt.

Environment Variables

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

$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)).

Exit Status

0

Success

1

Command error

2

Undefined command

3

Fatal error

4

Command warning (something went wrong during the command)

Bugs

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

Resources

• LTTng project website <https://lttng.org>
• LTTng documentation <https://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

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

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.

See Also

lttng-start(1), lttng(1)

Referenced By

lttng(1), lttng-destroy(1), lttng-rotate(1), lttng-snapshot(1), lttng-start(1).