'\" t
.\"     Title: lttng-rotate
.\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 14 June 2021
.\"    Manual: LTTng Manual
.\"    Source: LTTng 2.13.11
.\"  Language: English
.\"
.TH "LTTNG\-ROTATE" "1" "14 June 2021" "LTTng 2\&.13\&.11" "LTTng Manual"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
lttng-rotate \- Archive the current trace chunk of an LTTng recording session
.SH "SYNOPSIS"
.sp
.nf
\fBlttng\fR [\fIGENERAL OPTIONS\fR] \fBrotate\fR [\fB--no-wait\fR] [\fISESSION\fR]
.fi
.SH "DESCRIPTION"
.sp
The \fBlttng rotate\fR command archives to the file system the current trace chunk of:
.PP
With the \fISESSION\fR argument
.RS 4
The recording session named
\fISESSION\fR\&.
.RE
.PP
Without the \fISESSION\fR argument
.RS 4
The current recording session (see
\fBlttng-concepts\fR(7)
to learn more about the current recording session)\&.
.RE
.sp
This action is called a \fIrecording session rotation\fR\&.
.sp
See \fBlttng-concepts\fR(7) to learn more about the recording session rotation and trace chunk concepts\&.
.sp
You can use the \fBrotate\fR command:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Any time the recording session is active\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
A single time once the recording session becomes inactive\&.
.RE
.sp
See \fBlttng-concepts\fR(7) to learn more about the activity of a recording session\&.
.sp
By default, the \fBrotate\fR command ensures that LTTng finished performing the recording session rotation before it prints the path of the archived trace chunk and exits\&. The printed path is absolute when the recording session was created in normal mode and relative to the base output directory of the relay daemon (see the \fB--output\fR option of \fBlttng-relayd\fR(8)) when it was created in network streaming mode (see \fBlttng-create\fR(1))\&.
.sp
Make the command exit immediately with the \fB--no-wait\fR option\&. In this case, there\(cqs 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\&.
.sp
Because LTTng flushes the current sub\-buffers of the selected recording session when it performs a recording session rotation, archived trace chunks are never redundant, that is, they do not overlap over time like snapshots can (see \fBlttng-snapshot\fR(1))\&. Also, a rotation does NOT directly cause discarded event records or packets\&.
.sp
A \fBrotate-session\fR trigger action can also rotate a recording session (see \fBlttng-add-trigger\fR(1))\&.
.sp
See the \(lqEXAMPLES\(rq section below for usage examples\&.
.if n \{\
.sp
.\}
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBImportant\fR
.ps -1
.br
.RS 4
.sp
You may only use the \fBrotate\fR command when:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The selected recording session was created in normal mode or in network streaming mode (see
\fBlttng-create\fR(1))\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
LTTng is not currently performing an immediate rotation (this command)\&.
.RE
.sp .5v
.RE
.SH "OPTIONS"
.sp
See \fBlttng\fR(1) for \fIGENERAL OPTIONS\fR\&.
.PP
\fB-n\fR, \fB--no-wait\fR
.RS 4
Do not ensure that the recording session rotation operation is completed before exiting\&.
.RE
.SS "Program information"
.PP
\fB-h\fR, \fB--help\fR
.RS 4
Show help\&.
.sp
This option attempts to launch
\fB/usr/bin/man\fR
to view this manual page\&. Override the manual pager path with the
\fBLTTNG_MAN_BIN_PATH\fR
environment variable\&.
.RE
.PP
\fB--list-options\fR
.RS 4
List available command options and quit\&.
.RE
.SH "EXIT STATUS"
.PP
\fB0\fR
.RS 4
Success
.RE
.PP
\fB1\fR
.RS 4
Command error
.RE
.PP
\fB2\fR
.RS 4
Undefined command
.RE
.PP
\fB3\fR
.RS 4
Fatal error
.RE
.PP
\fB4\fR
.RS 4
Command warning (something went wrong during the command)
.RE
.SH "ENVIRONMENT"
.PP
\fBLTTNG_ABORT_ON_ERROR\fR
.RS 4
Set to
\fB1\fR
to abort the process after the first error is encountered\&.
.RE
.PP
\fBLTTNG_HOME\fR
.RS 4
Path to the LTTng home directory\&.
.sp
Defaults to
\fB$HOME\fR\&.
.sp
Useful when the Unix user running the commands has a non\-writable home directory\&.
.RE
.PP
\fBLTTNG_MAN_BIN_PATH\fR
.RS 4
Absolute path to the manual pager to use to read the LTTng command\-line help (with
\fBlttng-help\fR(1)
or with the
\fB--help\fR
option) instead of
\fB/usr/bin/man\fR\&.
.RE
.PP
\fBLTTNG_SESSION_CONFIG_XSD_PATH\fR
.RS 4
Path to the directory containing the
\fBsession.xsd\fR
recording session configuration XML schema\&.
.RE
.PP
\fBLTTNG_SESSIOND_PATH\fR
.RS 4
Absolute path to the LTTng session daemon binary (see
\fBlttng-sessiond\fR(8)) to spawn from the
\fBlttng-create\fR(1)
command\&.
.sp
The
\fB--sessiond-path\fR
general option overrides this environment variable\&.
.RE
.SH "FILES"
.PP
\fB$LTTNG_HOME/.lttngrc\fR
.RS 4
Unix user\(cqs LTTng runtime configuration\&.
.sp
This is where LTTng stores the name of the Unix user\(cqs current recording session between executions of
\fBlttng\fR(1)\&.
\fBlttng-create\fR(1)
and
\fBlttng-set-session\fR(1)
set the current recording session\&.
.RE
.PP
\fB$LTTNG_HOME/lttng-traces\fR
.RS 4
Default output directory of LTTng traces in local and snapshot modes\&.
.sp
Override this path with the
\fB--output\fR
option of the
\fBlttng-create\fR(1)
command\&.
.RE
.PP
\fB$LTTNG_HOME/.lttng\fR
.RS 4
Unix user\(cqs LTTng runtime and configuration directory\&.
.RE
.PP
\fB$LTTNG_HOME/.lttng/sessions\fR
.RS 4
Default directory containing the Unix user\(cqs saved recording session configurations (see
\fBlttng-save\fR(1)
and
\fBlttng-load\fR(1))\&.
.RE
.PP
\fB/etc/lttng/sessions\fR
.RS 4
Directory containing the system\-wide saved recording session configurations (see
\fBlttng-save\fR(1)
and
\fBlttng-load\fR(1))\&.
.RE
.if n \{\
.sp
.\}
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.RS 4
.sp
\fB$LTTNG_HOME\fR defaults to the value of the \fBHOME\fR environment variable\&.
.sp .5v
.RE
.SH "EXAMPLES"
.PP
\fBExample\ \&1.\ \&Rotate the current recording session\&.\fR
.RS 4
.sp
.if n \{\
.RS 4
.\}
.nf
$ lttng rotate
.fi
.if n \{\
.RE
.\}
.RE
.PP
\fBExample\ \&2.\ \&Rotate a specific recording session\&.\fR
.RS 4
.sp
.if n \{\
.RS 4
.\}
.nf
$ lttng rotate my\-session
.fi
.if n \{\
.RE
.\}
.RE
.PP
\fBExample\ \&3.\ \&Rotate the current recording session without waiting for completion\&.\fR
.RS 4
.sp
See the \fB--no-wait\fR option\&.
.sp
.if n \{\
.RS 4
.\}
.nf
$ lttng rotate \-\-no\-wait
.fi
.if n \{\
.RE
.\}
.RE
.SH "RESOURCES"
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
LTTng project website <https://lttng.org>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
LTTng documentation <https://lttng.org/docs>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
LTTng bug tracker <https://bugs.lttng.org>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Git repositories <https://git.lttng.org>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
GitHub organization <https://github.com/lttng>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Continuous integration <https://ci.lttng.org/>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Mailing list <https://lists.lttng.org/>
for support and development:
\fBlttng-dev@lists.lttng.org\fR
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
IRC channel <irc://irc.oftc.net/lttng>:
\fB#lttng\fR
on
\fBirc.oftc.net\fR
.RE
.SH "COPYRIGHT"
.sp
This program is part of the LTTng\-tools project\&.
.sp
LTTng\-tools is distributed under the GNU General Public License version\ \&2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>\&. See the \fBLICENSE\fR <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file for details\&.
.SH "THANKS"
.sp
Special thanks to Michel Dagenais and the DORSAL laboratory <http://www.dorsal.polymtl.ca/> at \('Ecole Polytechnique de Montr\('eal for the LTTng journey\&.
.sp
Also thanks to the Ericsson teams working on tracing which helped us greatly with detailed bug reports and unusual test cases\&.
.SH "SEE ALSO"
.sp
\fBlttng\fR(1), \fBlttng-disable-rotation\fR(1), \fBlttng-enable-rotation\fR(1), \fBlttng-concepts\fR(7)