lttng-load — Load LTTng tracing session configurations
lttng [GENERAL OPTIONS] load [--force] [--input-path=PATH] [--override-url=URL] [SESSION[--override-name=NAME]]
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:
$LTTNG_HOME/.lttng/sessions ($LTTNG_HOME defaults to $HOME)
/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.
Aspects of the loaded configurations can be overridden at load time
using the --override-url and --override-name options.
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).
-a, --all
Load all tracing session configurations (default).
-f, --force
Overwrite existing tracing sessions when loading.
-i PATH, --input-path=PATH
Load tracing session configurations from PATH, either a directory
or a file, instead of loading them from the default search
directories.
--override-name=NAME
Override the name of the loaded tracing session configuration,
SESSION, with NAME.
You must specify a tracing session name to load (SESSION) and not
use the --all option when using this option.
--override-url=URL
Override the URL of the loaded tracing session configurations
with URL.
This is the equivalent of the --set-url option of
lttng-create(1). The validity of the URL override depends on the
type of tracing session configurations to load. This option applies to
all the loaded tracing session configurations.
-h, --help
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-options
List available command options.
LTTNG_ABORT_ON_ERROR
Set to 1 to abort the process after the first error is encountered.
LTTNG_HOME
Overrides the $HOME environment variable. Useful when the user
running the commands has a non-writable home directory.
LTTNG_MAN_BIN_PATH
Absolute path to the man pager to use for viewing help information
about LTTng commands (using lttng-help(1) or
lttng COMMAND --help).
LTTNG_SESSION_CONFIG_XSD_PATH
Path in which the session.xsd session configuration XML
schema may be found.
LTTNG_SESSIOND_PATH
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.
$LTTNG_HOME/.lttngrc
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.
$LTTNG_HOME/lttng-traces
Default output directory of LTTng traces. This can be overridden
with the --output option of the lttng-create(1)
command.
$LTTNG_HOME/.lttng
User LTTng runtime and configuration directory.
$LTTNG_HOME/.lttng/sessions
Default location of saved user tracing sessions (see lttng-save(1) and lttng-load(1)).
/etc/lttng/sessions
System-wide location of saved tracing sessions (see lttng-save(1) and lttng-load(1)).
Note:$LTTNG_HOME defaults to $HOME when not explicitly set.
Success
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.
Mailing list for support and
development: lttng-dev@lists.lttng.org
IRC channel: #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. See the
LICENSE file
for details.
Special thanks to Michel Dagenais and the DORSAL laboratory 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.