NAME

       lttng-enable-rotation - Set a tracing session's rotation schedule

SYNOPSIS

       lttng [GENERAL OPTIONS] enable-rotation [--session=SESSION]
             (--timer=PERIOD | --size=SIZE | --timer=PERIOD --size=SIZE)

DESCRIPTION

       The lttng enable-rotation command sets a rotation schedule for the current tracing session, or for the
       tracing session named SESSION if provided. See lttng-rotate(1) for more information about the concepts of
       a tracing session rotation and a trace chunk.

       With the --timer option, the rotation schedule is set so that an automatic rotation occurs at least every
       PERIOD (microseconds without a unit suffix).

       With the --size option, the rotation schedule is set so that an automatic rotation occurs every time the
       total size of the flushed part of the current trace chunk is at least SIZE (bytes without a unit suffix).

       For both --timer and --size options, LTTng checks the schedule condition periodically using the monitor
       timers of the tracing session’s channels (see the --monitor-timer option of the lttng-enable-channel(1)
       command). This means that:

       •   With the --timer option, the automatic rotation can occur when the elapsed time since the last
           automatic rotation is slightly greater than PERIOD. The exact precision is governed by the monitor
           timer’s precision, which relies on the precision of the platform’s implementation of POSIX timers.

       •   With the --size option, the automatic rotation can occur when the size of the flushed part of the
           current trace chunk is greater than SIZE.

       You can combine the --timer and --size options.

       The naming convention of a trace chunk archive which an automatic rotation creates is the same as with
       the immediate rotation command, lttng-rotate(1).

       You can unset a rotation schedule with the lttng-disable-rotation(1) command.

       See LIMITATIONS for important limitations regarding this command.

OPTIONS

       General options are described in lttng(1).

   Rotation schedule condition
       --size=SIZE
           Set a rotation schedule so that an automatic rotation occurs every time the total size of the flushed
           part of the current trace chunk is at least SIZE bytes. The k (kiB), M (MiB), and G (GiB) suffixes
           are supported.

       --timer=PERIOD
           Set a rotation schedule so that an automatic rotation occurs at least every PERIOD microseconds. The
           ms (milliseconds), s (seconds), m (minutes), and h (hours) suffixes are supported.

   Target
       -s SESSION, --session=SESSION
           Set a rotation schedule for the tracing session named SESSION instead of the current tracing session.

   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.

LIMITATIONS

       The lttng enable-rotation command only works when:

       •   The tracing session is created in normal mode or in network streaming mode (see lttng-create(1)).

       •   No channel was created with a configured trace file count or size limit (see the --tracefile-size and
           --tracefile-count options in lttng-enable-channel(1)).

       For a given tracing session, LTTng only performs an automatic rotation when no other rotation is
       currently happening.

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)).

       /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

       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-rotate(1), lttng-disable-rotation(1), lttng(1)