X-Git-Url: https://git.liburcu.org/?p=lttng-tools.git;a=blobdiff_plain;f=doc%2Fman%2Flttng-rotate.1.txt;h=baebea94b44e5bd187b90d29a6de89fa39381a85;hp=c582126bd6a14137cdda0fde8c83942a6d72c86b;hb=26f0c7794376456fcb5b13d4eae91c0ccf0dfe66;hpb=65750bcdda3dd71b72683573d35a662c0b467a8f diff --git a/doc/man/lttng-rotate.1.txt b/doc/man/lttng-rotate.1.txt index c582126bd..baebea94b 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: 30 April 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 @@ -16,138 +16,78 @@ 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)). - -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. +The `lttng rotate` command archives to the file system +the current trace chunk of: -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. +With the 'SESSION' argument:: + The tracing session named 'SESSION'. -See <> for important limitations regarding -this command. +Without the 'SESSION' argument:: + The current tracing session (see man:lttng-concepts(7) to learn more + about the current tracing session). +This action is called a _tracing session rotation_. -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)). +See man:lttng-concepts(7) to learn more about the tracing session +rotation and trace chunk concepts. -A trace chunk archive contains, through tracing domain and possibly -UID/PID subdirectories, metadata and data stream files. +You can use the `rotate` command: -A trace chunk archive is, at the same time: +* Any time the tracing session is active. -* A self-contained LTTng trace. -* A member of a set of trace chunk archives which form the complete - trace of a tracing session. +* A single time once the tracing session becomes inactive. -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. +See man:lttng-concepts(7) to learn more about the activity of a +tracing session. -When LTTng performs a tracing session rotation, it names the resulting -trace chunk archive as such, relative to the tracing session's output -directory: +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)). -[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: +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. ----- -archives/20171119T152407-0500-20171119T151422-0500-3 ----- +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. +A `rotate-session` trigger action can also rotate a tracing session (see +man:lttng-add-trigger(1)). -include::common-cmd-options-head.txt[] +[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)). -option:-n, option:--no-wait:: - Do not ensure that the rotation is done before returning to - the prompt. +* 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-help-options.txt[] +include::common-cmd-options-head.txt[] -[[limitations]] -LIMITATIONS ------------ -The `lttng rotate` command only works when: -* The tracing session is created in normal mode or in network streaming - mode (see man:lttng-create(1)). +option:-n, option:--no-wait:: + Do not ensure that the tracing session rotation operation is + completed before exiting. -* 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)). -* No immediate rotation (`lttng rotate`) is currently happening. +include::common-cmd-help-options.txt[] include::common-cmd-footer.txt[] @@ -155,6 +95,7 @@ include::common-cmd-footer.txt[] SEE ALSO -------- -man:lttng-enable-rotation(1), +man:lttng(1), +man:lttng-concepts(7), man:lttng-disable-rotation(1), -man:lttng(1) +man:lttng-enable-rotation(1)