LTTNG-ROTATE(1)                 LTTng Manual                 LTTNG-ROTATE(1)

NAME         top

       lttng-rotate - Archive a tracing session's current trace chunk

SYNOPSIS         top

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

DESCRIPTION         top

       The lttng rotate command archives the current trace chunk of the
       current tracing session, or of the tracing session named SESSION if
       provided, to the file system. This action is called a tracing session

       Once a trace chunk is archived, LTTng does not manage it anymore: you
       can read it, modify it, move it, or remove it.

       An archived trace chunk is a collection of metadata and data stream
       files which form a self-contained trace.

       The current trace chunk of a given tracing session includes:

       ·   The stream files already written to the file system, and which
           are not part of a previously archived trace chunk, since the most
           recent event amongst:

           ·   The first time the tracing session was started with

           ·   The last rotation, either an immediate one with lttng rotate,
               or an automatic one from a rotation schedule previously set
               with lttng-enable-rotation(1).

       ·   The content of all the non-flushed sub-buffers of the tracing
           session’s channels.

       You can use lttng rotate either at any time when the tracing session
       is active (see lttng-start(1)), or a single time once the tracing
       session becomes inactive (see lttng-stop(1)).

       By default, the lttng rotate command ensures that the rotation is
       done before printing the archived trace chunk’s path and returning to
       the prompt. The printed path is absolute when the tracing session was
       created in normal mode and relative to the relay daemon’s output
       directory (see the --output option in lttng-relayd(8)) when it was
       created in network streaming mode (see lttng-create(1)).

       With the --no-wait option, the command finishes immediately, hence a
       rotation might not be completed when the command is done. In this
       case, there is no easy way to know when the current trace chunk is
       archived, and the command does not print the archived trace chunk’s

       Because a rotation causes the tracing session’s current sub-buffers
       to be flushed, archived trace chunks are never redundant, that is,
       they do not overlap over time like snapshots can (see
       lttng-snapshot(1)). Also, a rotation does not directly cause
       discarded event records or packets.

       See LIMITATIONS for important limitations regarding this command.

   Trace chunk archive naming
       A trace chunk archive is a subdirectory of a tracing session’s output
       directory (see the --output option in lttng-create(1)) which
       contains, through tracing domain and possibly UID/PID subdirectories,
       metadata and data stream files.

       A trace chunk archive is, at the same time:

       ·   A self-contained LTTng trace.

       ·   A member of a set of trace chunk archives which form the complete
           trace of a tracing session.

       In other words, an LTTng trace reader can read both the tracing
       session output directory (all the trace chunk archives), or a single
       trace chunk archive.

       When a tracing session rotation occurs, the created trace chunk
       archive is named:


           Date and time of the beginning of the trace chunk archive with
           the ISO 8601-compatible YYYYmmddTHHMMSS±HHMM form, where YYYYmmdd
           is the date and HHMMSS±HHMM is the time with the time zone offset
           from UTC.

           Example: 20171119T152407-0500

           Date and time of the end of the trace chunk archive with the ISO
           8601-compatible YYYYmmddTHHMMSS±HHMM form, where YYYYmmdd is the
           date and HHMMSS±HHMM is the time with the time zone offset from

           Example: 20180118T152407+0930

           Unique numeric identifier of the trace chunk within its tracing

       Trace chunk archive name example:

OPTIONS         top

       General options are described in lttng(1).

       -n, --no-wait
           Do not ensure that the rotation is done before returning to the

   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 available command options.

LIMITATIONS         top

       The lttng rotate 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

       ·   No immediate rotation (lttng rotate) is currently happening.


           Set to 1 to abort the process after the first error is

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

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

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

           Full session daemon binary path.

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

       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

FILES         top

           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.

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

           User LTTng runtime and configuration directory.

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

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

           $LTTNG_HOME defaults to $HOME when not explicitly set.

EXIT STATUS         top


           Command error

           Undefined command

           Fatal error

           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 <>.

RESOURCES         top

       ·   LTTng project website <>

       ·   LTTng documentation <>

       ·   Git repositories <>

       ·   GitHub organization <>

       ·   Continuous integration <>

       ·   Mailing list <> for support and

       ·   IRC channel <irc://>: #lttng on

COPYRIGHTS         top

       This program is part of the LTTng-tools project.

       LTTng-tools is distributed under the GNU General Public License
       version 2 <>.
       See the LICENSE <
       tools/blob/master/LICENSE> file for details.

THANKS         top

       Special thanks to Michel Dagenais and the DORSAL laboratory
       <> 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

       LTTng-tools is currently maintained by Jérémie Galarneau

SEE ALSO         top

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

COLOPHON         top

       This page is part of the LTTng-Tools (    LTTng tools) project.
       Information about the project can be found at ⟨⟩.
       It is not known how to report bugs for this man page; if you know,
       please send a mail to  This page was obtained
       from the project's upstream Git repository
       ⟨git://⟩ on 2019-05-09.  (At that time,
       the date of the most recent commit that was found in the repository
       was 2019-05-04.)  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-to-
       date source for the page, or you have corrections or improvements to
       the information in this COLOPHON (which is not part of the original
       manual page), send a mail to

LTTng 2.12.0-pre                 10/29/2018                  LTTNG-ROTATE(1)

Pages that refer to this page: lttng(1)lttng-destroy(1)lttng-enable-channel(1)lttng-enable-rotation(1)lttng-regenerate(1)lttng-stop(1)