lttng [GENERAL OPTIONS] load [--force] [--input-path=PATH] [SESSION]
The lttng load command loads the configurations of one or more tracing sessions from files.
The lttng load command is used in conjunction with the lttng-save(1) command to save and restore the complete configurations of tracing sessions. This includes the enabled channels and event rules, the context added to channels, the tracing activity, and more.
Once one or more tracing session configurations are loaded, they appear exactly as they were saved from the user's point of view.
The following directories are searched, non-recursively, in this order for configuration files:
- 1. $LTTNG_HOME/.lttng/sessions ($LTTNG_HOME defaults to $HOME)
- 2. /usr/local/etc/lttng/sessions
The input path can be overridden with the --input-path option. When this option is specified, the default directories are NOT searched for configuration files. When it's not specified, both default directories are searched for configuration files.
If the input path is a directory, then:
- • If SESSION is specified, the tracing session configuration named SESSION is searched for in all the files of this directory and loaded if found.
- • If SESSION is not specified, the --all option is implicit: all the tracing session configurations found in all the files in this directory are loaded.
If the input path is a file, then:
- • If SESSION is specified, the tracing session configuration named SESSION is searched for in this file and loaded if found.
- • If SESSION is not specified, the --all option is implicit: all the tracing session configurations found in this file are loaded.
By default, existing tracing sessions are not overwritten when loading: the command fails. The --force option can be used to allow this.
General options are described in lttng(1).
- Load all tracing session configurations (default).
- Overwrite existing tracing sessions when loading.
- Load tracing session configurations from PATH, either a directory or a file, instead of loading them from the default search directories.
Show command help.
This option, like lttng-help(1), attempts to launch /usr/bin/man to view the command's man page. The path to the man pager can be overridden by the LTTNG_MAN_BIN_PATH environment variable.
- List available command options.
- Set to 1 to abort the process after the first error is encountered.
- Overrides the $HOME environment variable. Useful when the user running the commands has a non-writable home directory.
- Absolute path to the man pager to use for viewing help information about LTTng commands (using lttng-help(1) or lttng COMMAND --help).
- Path in which the session.xsd session configuration XML schema may be found.
Full session daemon binary path.
The --sessiond-path option has precedence over this environment variable.
Note that the lttng-create(1) command can spawn an LTTng session daemon automatically if none is running. See lttng-sessiond(8) for the environment variables influencing the execution of the session daemon.
User LTTng runtime configuration.
This is where the per-user current tracing session is stored between executions of lttng(1). The current tracing session can be set with lttng-set-session(1). See lttng-create(1) for more information about tracing sessions.
- Default output directory of LTTng traces. This can be overridden with the --output option of the lttng-create(1) command.
- User LTTng runtime and configuration directory.
$LTTNG_HOME defaults to $HOME when not explicitly set.
- Command error
- Undefined command
- Fatal error
- Command warning (something went wrong during the command)
If you encounter any issue or usability problem, please report it on the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-tools>.
- • LTTng project website <http://lttng.org>
- • LTTng documentation <http://lttng.org/docs>
- • Git repositories <http://git.lttng.org>
- • GitHub organization <http://github.com/lttng>
- • Continuous integration <http://ci.lttng.org/>
- • IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
This program is part of the LTTng-tools project.
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 LICENSE <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file for details.
Special thanks to Michel Dagenais and the DORSAL laboratory <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for the LTTng journey.
Also thanks to the Ericsson teams working on tracing which helped us greatly with detailed bug reports and unusual test cases.
LTTng-tools was originally written by Mathieu Desnoyers, Julien Desfossez, and David Goulet. More people have since contributed to it.
LTTng-tools is currently maintained by Jérémie Galarneau <mailto:[email protected]>.