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

   1 lttng-enable-rotation(1)
   2 ========================
   3 :revdate: 13 November 2018
   4
   5
   6 NAME
   7 ----
   8 lttng-enable-rotation - Set a tracing session's rotation schedule
   9
  10
  11 SYNOPSIS
  12 --------
  13 [verse]
  14 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* [option:--session='SESSION']
  15       (option:--timer='PERIOD' | option:--size='SIZE' | option:--timer='PERIOD' option:--size='SIZE')
  16
  17
  18 DESCRIPTION
  19 -----------
  20 The `lttng enable-rotation` command sets a rotation schedule for the
  21 current tracing session, or for the tracing session named 'SESSION' if
  22 provided. See man:lttng-rotate(1) for more information about the
  23 concepts of a tracing session _rotation_ and a _trace chunk_.
  24
  25 With the option:--timer option, the rotation schedule is set so that an
  26 automatic rotation occurs at least every 'PERIOD' (microseconds without
  27 a unit suffix).
  28
  29 With the option:--size option, the rotation schedule is set
  30 so that an automatic rotation occurs every time the total size of the
  31 flushed part of the current trace chunk is at least 'SIZE' (bytes
  32 without a unit suffix).
  33
  34 For both option:--timer and option:--size options, LTTng checks the
  35 schedule condition periodically using the monitor timers of the tracing
  36 session's channels (see the nloption:--monitor-timer option of the
  37 man:lttng-enable-channel(1) command). This means that:
  38
  39 * With the option:--timer option, the automatic rotation can occur when
  40   the elapsed time since the last automatic rotation is slightly greater
  41   than 'PERIOD'. The exact precision is governed by the monitor timer's
  42   precision, which relies on the precision of the platform's
  43   implementation of POSIX timers.
  44
  45 * With the option:--size option, the automatic rotation can occur when
  46   the size of the flushed part of the current trace chunk is greater
  47   than 'SIZE'.
  48
  49 You can combine the option:--timer and option:--size options.
  50
  51 The naming convention of a trace chunk archive which an automatic
  52 rotation creates is the same as with the immediate rotation command,
  53 man:lttng-rotate(1).
  54
  55 You can unset a rotation schedule with the man:lttng-disable-rotation(1)
  56 command.
  57
  58 See <<limitations,LIMITATIONS>> for important limitations regarding
  59 this command.
  60
  61
  62 include::common-cmd-options-head.txt[]
  63
  64
  65 Rotation schedule condition
  66 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
  67 option:--size='SIZE'::
  68     Set a rotation schedule so that an automatic rotation occurs every
  69     time the total size of the flushed part of the current trace chunk
  70     is at least 'SIZE' bytes. The `k` (kiB), `M` (MiB), and `G` (GiB)
  71     suffixes are supported.
  72
  73 option:--timer='PERIOD'::
  74     Set a rotation schedule so that an automatic rotation occurs at
  75     least every 'PERIOD' microseconds. The `ms` (milliseconds), `s`
  76     (seconds), `m` (minutes), and `h` (hours) suffixes are supported.
  77
  78
  79 Target
  80 ~~~~~~
  81 option:-s 'SESSION', option:--session='SESSION'::
  82     Set a rotation schedule for the tracing session named 'SESSION'
  83     instead of the current tracing session.
  84
  85
  86 include::common-cmd-help-options.txt[]
  87
  88
  89 [[limitations]]
  90 LIMITATIONS
  91 -----------
  92 The `lttng enable-rotation` command only works when:
  93
  94 * The tracing session is created in normal mode or in network streaming
  95   mode (see man:lttng-create(1)).
  96
  97 * No channel was created with a configured trace file count or size
  98   limit (see the nloption:--tracefile-size and
  99   nloption:--tracefile-count options in man:lttng-enable-channel(1)).
 100
 101 For a given tracing session, LTTng only performs an automatic rotation
 102 when no other rotation is currently happening.
 103
 104
 105 include::common-cmd-footer.txt[]
 106
 107
 108 SEE ALSO
 109 --------
 110 man:lttng-rotate(1),
 111 man:lttng-disable-rotation(1),
 112 man:lttng(1)