X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=doc%2Fman%2Flttng-rotate.1.txt;h=91df503feba6dbcc6603b3d28cdc612c67d99bfb;hb=da39b67ce2828bfc63a02db969048bfe1abd4ca0;hp=c582126bd6a14137cdda0fde8c83942a6d72c86b;hpb=4605890e0a926f1c88355051dcd6d8a8dd135c58;p=lttng-tools.git diff --git a/doc/man/lttng-rotate.1.txt b/doc/man/lttng-rotate.1.txt index c582126bd..91df503fe 100644 --- a/doc/man/lttng-rotate.1.txt +++ b/doc/man/lttng-rotate.1.txt @@ -1,11 +1,11 @@ lttng-rotate(1) =============== -:revdate: 18 October 2019 +:revdate: 17 May 2021 NAME ---- -lttng-rotate - Archive a tracing session's current trace chunk +lttng-rotate - Archive the current trace chunk of an LTTng tracing session SYNOPSIS @@ -16,145 +16,121 @@ SYNOPSIS DESCRIPTION ----------- -The `lttng rotate` command archives the current trace chunk of the -current tracing session, or of the tracing session named 'SESSION' if -provided, to the file system. This action is called a tracing session -_rotation_. - -Once LTTng archives a trace chunk, it does not manage it anymore: you -can read it, modify it, move it, or remove it. - -An _archived trace chunk_ is a collection of metadata and data stream -files which form a self-contained LTTng trace. - -The _current trace chunk_ of a given tracing session includes: - -* The stream files already written to the file system, and which are - not part of a previously archived trace chunk, since the most recent - event amongst: -** The first time the tracing session was started with - man:lttng-start(1). -** The last rotation, either an immediate one with `lttng rotate`, or an - automatic one from a rotation schedule previously set with - man:lttng-enable-rotation(1). -* The content of all the non-flushed sub-buffers of the tracing - session's channels. - -You can use `lttng rotate`: - -* At any time when the tracing session is active (see - man:lttng-start(1)). -* A single time once the tracing session becomes inactive - (see man:lttng-stop(1)). - -By default, the `lttng rotate` command ensures that LTTng finished -performing the tracing session rotation before it prints the archived -trace chunk's path and exits. The printed path is absolute when the -tracing session was created in normal mode and relative to the relay -daemon's output directory (see the nloption:--output option in -man:lttng-relayd(8)) when it was created in network streaming mode (see -man:lttng-create(1)). +The `lttng rotate` command archives to the file system +the current trace chunk of: -With the option:--no-wait option, the command finishes immediately, so -that LTTng might not have completed the rotation when the command exits. -In this case, there is no easy way to know when the current trace chunk -becomes archived, and the command does not print the archived trace -chunk's path. +With the 'SESSION' argument:: + The tracing session named 'SESSION'. -Because when LTTng performs a tracing session rotation, it flushes the -tracing session's current sub-buffers, archived trace chunks are never -redundant, that is, they do not overlap over time like snapshots can -(see man:lttng-snapshot(1)). Also, a rotation does not directly cause -discarded event records or packets. +Without the 'SESSION' argument:: + The current tracing session (see man:lttng-concepts(7) to learn more + about the current tracing session). -See <> for important limitations regarding -this command. +This action is called a _tracing session rotation_. +See man:lttng-concepts(7) to learn more about the tracing session +rotation and trace chunk concepts. -Trace chunk archive naming -~~~~~~~~~~~~~~~~~~~~~~~~~~ -A trace chunk archive is a subdirectory of the `archives` subdirectory -within a tracing session's output directory (see the nloption:--output -option in man:lttng-create(1) and man:lttng-relayd(8)). +You can use the `rotate` command: -A trace chunk archive contains, through tracing domain and possibly -UID/PID subdirectories, metadata and data stream files. +* Any time the tracing session is active. -A trace chunk archive is, at the same time: +* A single time once the tracing session becomes inactive. -* A self-contained LTTng trace. -* A member of a set of trace chunk archives which form the complete - trace of a tracing session. +See man:lttng-concepts(7) to learn more about the activity of a +tracing session. -In other words, an LTTng trace reader can read both the tracing -session output directory (all the trace chunk archives), or a -single trace chunk archive. +By default, the `rotate` command ensures that LTTng finished performing +the tracing session rotation before it prints the path of the archived +trace chunk and exits. The printed path is absolute when the tracing +session was created in normal mode and relative to the base output +directory of the relay daemon (see the nloption:--output option of +man:lttng-relayd(8)) when it was created in network streaming mode (see +man:lttng-create(1)). -When LTTng performs a tracing session rotation, it names the resulting -trace chunk archive as such, relative to the tracing session's output -directory: +Make the command exit immediately with the option:--no-wait option. In +this case, there's no easy way to know when the current trace chunk +becomes archived, and the command does :not: print the path of the +archived trace chunk. -[verse] -archives/__BEGIN__-__END__-__ID__ - -__BEGIN__:: - Date and time of the beginning of the trace chunk archive with - the ISO{nbsp}8601-compatible `YYYYmmddTHHMMSS±HHMM` form, where - `YYYYmmdd` is the date and `HHMMSS±HHMM` is the time with the - time zone offset from UTC. -+ -Example: `20171119T152407-0500` - -__END__:: - Date and time of the end of the trace chunk archive with - the ISO{nbsp}8601-compatible `YYYYmmddTHHMMSS±HHMM` form, where - `YYYYmmdd` is the date and `HHMMSS±HHMM` is the time with the - time zone offset from UTC. -+ -Example: `20180118T152407+0930` - -__ID__:: - Unique numeric identifier of the trace chunk within its tracing - session. - -Trace chunk archive name example: +Because LTTng flushes the current sub-buffers of the selected tracing +session when it performs a tracing session rotation, archived trace +chunks are never redundant, that is, they do not overlap over time like +snapshots can (see man:lttng-snapshot(1)). Also, a rotation does :not: +directly cause discarded event records or packets. ----- -archives/20171119T152407-0500-20171119T151422-0500-3 ----- +A `rotate-session` trigger action can also rotate a tracing session (see +man:lttng-add-trigger(1)). + +See the ``<>'' section below for usage examples. + +[IMPORTANT] +==== +You may only use the `rotate` command when: + +* The selected tracing session was created in normal mode or in network + streaming mode (see man:lttng-create(1)). + +* No channel was created with a configured trace file count or size + limit (see the nloption:--tracefile-size and + nloption:--tracefile-count options of the man:lttng-enable-channel(1) + command). + +* LTTng is not currently performing an immediate rotation (this + command). +==== -include::common-cmd-options-head.txt[] +include::common-lttng-cmd-options-head.txt[] option:-n, option:--no-wait:: - Do not ensure that the rotation is done before returning to - the prompt. + Do not ensure that the tracing session rotation operation is + completed before exiting. -include::common-cmd-help-options.txt[] +include::common-lttng-cmd-help-options.txt[] -[[limitations]] -LIMITATIONS ------------ -The `lttng rotate` command only works when: +include::common-lttng-cmd-after-options.txt[] -* The tracing session is created in normal mode or in network streaming - mode (see man:lttng-create(1)). -* No channel was created with a configured trace file count or size - limit (see the nloption:--tracefile-size and - nloption:--tracefile-count options in man:lttng-enable-channel(1)). +[[examples]] +EXAMPLES +-------- +.Rotate the current tracing session. +==== +[role="term"] +---- +$ lttng rotate +---- +==== + +.Rotate a specific tracing session. +==== +[role="term"] +---- +$ lttng rotate my-session +---- +==== -* No immediate rotation (`lttng rotate`) is currently happening. +.Rotate the current tracing session without waiting for completion. +==== +See the option:--no-wait option. +[role="term"] +---- +$ lttng rotate --no-wait +---- +==== -include::common-cmd-footer.txt[] + +include::common-footer.txt[] SEE ALSO -------- -man:lttng-enable-rotation(1), +man:lttng(1), man:lttng-disable-rotation(1), -man:lttng(1) +man:lttng-enable-rotation(1), +man:lttng-concepts(7)