doc/man/lttng-enable-rotation.1.txt

   1 lttng-enable-rotation(1)
   2 ========================
   3
   4
   5 NAME
   6 ----
   7 lttng-enable-rotation - Set a tracing session's rotation schedule
   8
   9
  10 SYNOPSIS
  11 --------
  12 [verse]
  13 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* [option:--session='SESSION']
  14       (option:--timer='PERIOD' | option:--size='SIZE' | option:--timer='PERIOD' option:--size='SIZE')
  15
  16
  17 DESCRIPTION
  18 -----------
  19 The `lttng enable-rotation` command sets a rotation schedule for the
  20 current tracing session, or for the tracing session named 'SESSION' if
  21 provided. See man:lttng-rotate(1) for more information about the
  22 concepts of a tracing session _rotation_ and a _trace chunk_.
  23
  24 With the option:--timer option, the rotation schedule is set so that an
  25 automatic rotation occurs at least every 'PERIOD' (microseconds without
  26 a unit suffix).
  27
  28 With the option:--size option, the rotation schedule is set
  29 so that an automatic rotation occurs every time the total size of the
  30 flushed part of the current trace chunk is at least 'SIZE' (bytes
  31 without a unit suffix).
  32
  33 For both option:--timer and option:--size options, LTTng checks the
  34 schedule condition periodically using the monitor timers of the tracing
  35 session's channels (see the nloption:--monitor-timer option of the
  36 man:lttng-enable-channel(1) command). This means that:
  37
  38 * With the option:--timer option, the automatic rotation can occur when
  39   the elapsed time since the last automatic rotation is slightly greater
  40   than 'PERIOD'. The exact precision is governed by the monitor timer's
  41   precision, which relies on the precision of the platform's
  42   implementation of POSIX timers.
  43
  44 * With the option:--size option, the automatic rotation can occur when
  45   the size of the flushed part of the current trace chunk is greater
  46   than 'SIZE'.
  47
  48 You can combine the option:--timer and option:--size options.
  49
  50 The naming convention of a trace chunk archive which an automatic
  51 rotation creates is the same as with the immediate rotation command,
  52 man:lttng-rotate(1).
  53
  54 You can unset a rotation schedule with the man:lttng-disable-rotation(1)
  55 command.
  56
  57 See <<limitations,LIMITATIONS>> for important limitations regarding
  58 this command.
  59
  60
  61 include::common-cmd-options-head.txt[]
  62
  63
  64 Rotation schedule condition
  65 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
  66 option:--size='SIZE'::
  67     Set a rotation schedule so that an automatic rotation occurs every
  68     time the total size of the flushed part of the current trace chunk
  69     is at least 'SIZE' bytes. The `k` (kiB), `M` (MiB), and `G` (GiB)
  70     suffixes are supported.
  71
  72 option:--timer='PERIOD'::
  73     Set a rotation schedule so that an automatic rotation occurs at
  74     least every 'PERIOD' microseconds. The `ms` (milliseconds), `s`
  75     (seconds), `m` (minutes), and `h` (hours) suffixes are supported.
  76
  77
  78 Target
  79 ~~~~~~
  80 option:-s 'SESSION', option:--session='SESSION'::
  81     Set a rotation schedule for the tracing session named 'SESSION'
  82     instead of the current tracing session.
  83
  84
  85 include::common-cmd-help-options.txt[]
  86
  87
  88 [[limitations]]
  89 LIMITATIONS
  90 -----------
  91 The `lttng enable-rotation` command only works when:
  92
  93 * The tracing session is created in normal mode or in network streaming
  94   mode (see man:lttng-create(1)).
  95
  96 * No channel was created with a configured trace file count or size
  97   limit (see the nloption:--tracefile-size and
  98   nloption:--tracefile-count options in man:lttng-enable-channel(1)).
  99
 100 For a given tracing session, LTTng only performs an automatic rotation
 101 when no other rotation is currently happening.
 102
 103
 104 include::common-cmd-footer.txt[]
 105
 106
 107 SEE ALSO
 108 --------
 109 man:lttng-rotate(1),
 110 man:lttng-disable-rotation(1),
 111 man:lttng(1)