X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=doc%2Fman%2Flttng-enable-rotation.1.txt;h=e8970cd97b64187eac8b3ad8647bfd8d2073477c;hp=ad753d0c9d7c5a7ff626a747d8d4a0cd8f999489;hb=437afa719f5e777dac77827298c443f450e0903e;hpb=980bb5fda2120f8d2a4e82fcf72be7cbbeb85fd2 diff --git a/doc/man/lttng-enable-rotation.1.txt b/doc/man/lttng-enable-rotation.1.txt index ad753d0c9..e8970cd97 100644 --- a/doc/man/lttng-enable-rotation.1.txt +++ b/doc/man/lttng-enable-rotation.1.txt @@ -4,22 +4,22 @@ lttng-enable-rotation(1) NAME ---- -lttng-enable-rotation - Set a tracing session's automatic rotation schedule +lttng-enable-rotation - Set a tracing session's rotation schedule SYNOPSIS -------- [verse] -*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* (option:--timer='PERIOD' | option:--size='SIZE') - [option:--session='SESSION'] +*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* [option:--session='SESSION'] + (option:--timer='PERIOD' | option:--size='SIZE' | option:--timer='PERIOD' option:--size='SIZE') DESCRIPTION ----------- -The `lttng enable-rotation` command sets an automatic rotation schedule -for the current tracing session, or for the tracing session named -'SESSION' if provided. See man:lttng-rotate(1) for more information -about the concepts of a tracing session _rotation_ and a _trace chunk_. +The `lttng enable-rotation` command sets a rotation schedule for the +current tracing session, or for the tracing session named 'SESSION' if +provided. See man:lttng-rotate(1) for more information about the +concepts of a tracing session _rotation_ and a _trace chunk_. With the option:--timer option, the rotation schedule is set so that an automatic rotation occurs at least every 'PERIOD' (microseconds without @@ -30,25 +30,29 @@ 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). -With both the option:--timer and option:--size options, LTTng checks the +For both option:--timer and option:--size options, LTTng checks the schedule condition periodically using the monitor timers of the tracing -session's channels. This means that, with the option:--timer option, the -automatic rotation can occur when the elapsed time since the last -automatic rotation is greater than 'PERIOD', and with the option:--size -option, the automatic rotation can occur when the size of the flushed -part of the current trace chunk is greater than 'SIZE'. See the -nloption:--monitor-timer option in man:lttng-enable-channel(1) for more -information about the monitor timer. +session's channels (see the nloption:--monitor-timer option of the +man:lttng-enable-channel(1) command). This means that: + +* With the option:--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 option:--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 option:--timer and option:--size options. The naming convention of a trace chunk archive which an automatic -rotation creates is the same as with the manual rotation command, +rotation creates is the same as with the immediate rotation command, man:lttng-rotate(1). -For a given tracing session, you cannot set multiple automatic rotation -schedules with the option:--timer or the option:--size option. - -You can unset an automatic rotation schedule with the -man:lttng-disable-rotation(1) command. +You can unset a rotation schedule with the man:lttng-disable-rotation(1) +command. See <> for important limitations regarding this command. @@ -57,28 +61,25 @@ this command. include::common-cmd-options-head.txt[] -Automatic rotation schedule condition -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -One of: - +Rotation schedule condition +~~~~~~~~~~~~~~~~~~~~~~~~~~~ option:--size='SIZE':: - Set an automatic 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. + 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. option:--timer='PERIOD':: - Set an automatic 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. + 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 ~~~~~~ option:-s 'SESSION', option:--session='SESSION':: - Set an automatic rotation schedule for the tracing session named - 'SESSION' instead of the current tracing session. + Set a rotation schedule for the tracing session named 'SESSION' + instead of the current tracing session. include::common-cmd-help-options.txt[]