$
lttng load
lttng-load — Load LTTng recording session configurations
lttng [GENERAL OPTIONS] load [--force
] [--input-path
=PATH
] [--override-url
=URL
] [--all
|SESSION
[--override-name
=NAME
]]
The lttng load
command loads the configurations of one or more
recording sessions from files.
See lttng-concepts(7) to learn more about recording sessions.
Use the load
command in conjunction with the lttng-save(1) command
to save and restore the complete configurations of recording sessions. A
recording session configuration includes the enabled channels and
recording event rules, the context fields to be recorded, the recording
activity, and more.
Once LTTng loads one or more recording session configurations, they appear exactly as they were saved from the user’s point of view.
LTTng searches the following directories, non-recursively, in this order for recording session configuration files:
$LTTNG_HOME/.lttng/sessions
($LTTNG_HOME
defaults to $HOME
)
/etc/lttng/sessions
Override the input path with the --input-path
=PATH
option. With
this option, LTTng does not search the default directories above.
PATH
can be the path of one of:
SESSION
argument
LTTng searches for the recording session configuration named
SESSION
in all the files of the directory PATH
and loads it
if found.
SESSION
argument
The --all
option is implicit: LTTng loads all the
recording session configurations found in all the files in the
directory PATH
.
SESSION
argument
LTTng searches for the recording session configuration named
SESSION
in the file PATH
and loads it if found.
SESSION
argument
The --all
option is implicit: LTTng loads all the
recording session configurations found in the file PATH
.
Override the output URL of the loaded recording session configurations
with the --override-url
option.
With the SESSION
argument, override the name of the loaded recording
session configuration with the --override-name
option.
By default, the load
command does not overwrite existing recording
sessions: the command fails. Allow the load
command to overwrite
existing recording sessions with the --force
option.
See the “EXAMPLES” section below for usage examples.
See lttng(1) for GENERAL OPTIONS.
-a
, --all
Load all the recording session configurations (default).
-f
, --force
Overwrite existing recording sessions when loading.
-i
PATH
, --input-path
=PATH
Load recording 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 recording session configuration,
SESSION
, with NAME
.
--override-url
=URL
Override the output URL of the loaded recording 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 recording session configurations to load. This option applies to
all the loaded recording session configurations.
-h
, --help
Show help.
This option attempts to launch /usr/bin/man
to view this manual page.
Override the manual pager path with the LTTNG_MAN_BIN_PATH
environment
variable.
--list-options
List available command options and quit.
Success
Command error
Undefined command
Fatal error
Command warning (something went wrong during the command)
LTTNG_ABORT_ON_ERROR
Set to 1
to abort the process after the first error is
encountered.
LTTNG_HOME
Path to the LTTng home directory.
Defaults to $HOME
.
Useful when the Unix user running the commands has a non-writable home directory.
LTTNG_MAN_BIN_PATH
Absolute path to the manual pager to use to read the LTTng
command-line help (with lttng-help(1) or with the
--help
option) instead of /usr/bin/man
.
LTTNG_SESSION_CONFIG_XSD_PATH
Path to the directory containing the session.xsd
recording session
configuration XML schema.
LTTNG_SESSIOND_PATH
Absolute path to the LTTng session daemon binary (see lttng-sessiond(8)) to spawn from the lttng-create(1) command.
The --sessiond-path
general option overrides this environment
variable.
$LTTNG_HOME/.lttngrc
Unix user’s LTTng runtime configuration.
This is where LTTng stores the name of the Unix user’s current recording session between executions of lttng(1). lttng-create(1) and lttng-set-session(1) set the current recording session.
$LTTNG_HOME/lttng-traces
Default output directory of LTTng traces in local and snapshot modes.
Override this path with the --output
option of the
lttng-create(1) command.
$LTTNG_HOME/.lttng
Unix user’s LTTng runtime and configuration directory.
$LTTNG_HOME/.lttng/sessions
Default directory containing the Unix user’s saved recording session configurations (see lttng-save(1) and lttng-load(1)).
/etc/lttng/sessions
Directory containing the system-wide saved recording session configurations (see lttng-save(1) and lttng-load(1)).
Note:$LTTNG_HOME
defaults to the value of the HOME
environment
variable.
Example:Load all the recording session configurations from the default search directories.
$
lttng load
Example:Load all the recording session configurations from a specific directory.
See the --input-path
option.
$
lttng load --input-path=/path/to/sessions
Example:Load a specific recording session configuration from the default search directories.
$
lttng load my-session
Example:Allow LTTng to overwrite existing recording sessions when loading.
See the --force
option.
$
lttng load --force
Example:Load a specific recording session configuration from a specific file, overriding its name.
See the --input-path
and --override-name
options.
$
lttng load my-session --input-path=/path/to/sessions.lttng \ --override-name=new-test
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.