lttng-enable-rotation(1)
========================
+:revdate: 13 November 2018
NAME
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
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'. Therefore the
-'PERIOD' and 'SIZE' arguments are approximations. 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 immediate rotation command,
Rotation schedule condition
~~~~~~~~~~~~~~~~~~~~~~~~~~~
-One of:
-
option:--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