| | 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) |
projects / lttng-tools.git / blame_incremental