table of contents
| LTTNG-LIST(1) | LTTng Manual | LTTNG-LIST(1) |
NAME¶
lttng-list - List LTTng recording sessions and instrumentation points
SYNOPSIS¶
List the recording sessions:
lttng [GENERAL OPTIONS] list
List the tracing domains of a recording session:
lttng [GENERAL OPTIONS] list --domain SESSION
List the channels and recording event rules of a recording session:
lttng [GENERAL OPTIONS] list [--channel=CHANNEL] SESSION
[--kernel] [--userspace] [--jul] [--log4j] [--log4j2] [--python]
[--style=(compact | breathe)] [--no-truncate]
[--mem-usage=(total | compact | full)]
List the available LTTng tracepoints, Linux system calls, and/or Java/Python loggers:
lttng [GENERAL OPTIONS] list
[--kernel [--syscall]] [--userspace [--fields]]
[--jul] [--log4j] [--log4j2] [--python]
DESCRIPTION¶
The lttng list command lists:
Without arguments
See the “Session daemon connection” section of lttng(1) to learn how a user application connects to a session daemon.
The command shows recording session properties such as their output directories/URLs and whether or not they’re active.
The name of the current recording session is underlined.
With the SESSION argument
With the --domain option
Without the --domain option
With the --channel=CHANNEL option
Without the --channel option
By default, the command shows the total memory usage of each channel. Control the memory usage display mode with the --mem-usage option.
Use the dedicated tracing domain options (--kernel, --userspace, --jul, --log4j, --log4j2, and --python) to only show specific channels.
Without the SESSION argument and with at least one dedicated tracing domain option
With the --kernel option
Without the --syscall option
With the --syscall option
With the --userspace option
Also list the available instrumentation point fields with the --fields option.
With the --jul, --log4j, --log4j2, and/or --python options
See lttng-concepts(7) to learn more about recording sessions, tracing domains, channels, recording event rules, and instrumentation points.
By default, the command adds empty lines between blocks of related information. Remove those empty lines with the --style=compact option.
This command shows colored text when the terminal supports it. Override the terminal coloring behaviour with the LTTNG_TERM_COLOR and NO_COLOR environment variables.
See the “EXAMPLES” section below for usage examples.
List the channels and recording event rules of the current recording session (see lttng-concepts(7) to learn more) with the lttng-status(1) command.
Visual language¶
The lttng list command uses a structured visual language designed to make complex tracing configurations easier to read and scan. It combines terminal colors, Unicode symbols, and indentation to express hierarchy, state, and metadata.
Color semantics:
| Color | Meaning |
| Green | Enabled, active, or valid items. |
| Red | Disabled, inactive, or invalid items. |
| Cyan | Important object nodes: recording sessions, tracing domains, channels, and event rules. Those nodes act as section headers. |
| Yellow | Metadata such as counts and timestamps. |
| Magenta | Warning information. |
Symbolic conventions:
| Symbol | Meaning |
| • and ◼ | Active/inactive recording session. |
| ✓ and × | Enabled/disabled channel or event rule. |
| 🞂 | Attribute or attribute group. |
| ┆ | Vertical continuation. |
OPTIONS¶
See lttng(1) for GENERAL OPTIONS.
Tracing domain¶
-j, --jul
Without the SESSION argument
With the SESSION argument
-k, --kernel
Without the SESSION argument
With the SESSION argument
-l, --log4j
Without the SESSION argument
With the SESSION argument
--log4j2
Without the SESSION argument
With the SESSION argument
-p, --python
Without the SESSION argument
With the SESSION argument
-u, --userspace
Without the SESSION argument
With the SESSION argument
Filtering¶
-c CHANNEL, --channel=CHANNEL
Only available with the SESSION argument.
-d, --domain
-f, --fields
--syscall
Display¶
--mem-usage=MODE
MODE is one of:
total (default)
compact
full
Only available with the SESSION argument.
--no-truncate
By default, the command truncates lines, adding an ellipsis, to fit the current terminal width.
--style=STYLE
STYLE is one of:
breathe (default)
compact
Program information¶
-h, --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
EXIT STATUS¶
0
1
2
3
4
ENVIRONMENT¶
LTTNG_ABORT_ON_ERROR
LTTNG_HOME
Defaults to $HOME.
Useful when the Unix user running the commands has a non-writable home directory.
LTTNG_LIST_LEGACY
Note that the legacy output doesn’t show anything related to features introduced after LTTng 2.14.
LTTNG_MAN_BIN_PATH
LTTNG_NO_UTF_8
LTTNG_SESSION_CONFIG_XSD_PATH
LTTNG_SESSIOND_PATH
The --sessiond-path general option overrides this environment variable.
LTTNG_TERM_COLOR
The NO_COLOR environment variable overrides this.
One of:
auto (default)
always
never
NO_COLOR
See NO_COLOR <https://no-color.org/> to learn more.
FILES¶
$LTTNG_HOME/.lttngrc
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
Override this path with the --output option of the lttng-create(1) command.
$LTTNG_HOME/.lttng
$LTTNG_HOME/.lttng/sessions
/etc/lttng/sessions
Note
$LTTNG_HOME defaults to the value of the HOME environment variable.
EXAMPLES¶
Example 1. List the recording sessions.
$ lttng list
Example 2. Show the details of a specific recording session.
$ lttng list my-session
Example 3. List the available Linux kernel system call instrumentation points.
$ lttng list --kernel --syscall
Example 4. List the available user space tracepoints with their fields.
See the --fields option.
$ lttng list --userspace --fields
Example 5. List the tracing domains of a specific recording session having at least one channel.
See the --domain option.
$ lttng list --domain my-session
Example 6. Show the details of a specific channel, including its current data stream infos, in a specific recording session.
See the --channel option.
$ lttng list my-session --channel=channel0 --stream-info-details
RESOURCES¶
COPYRIGHT¶
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.
THANKS¶
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.
SEE ALSO¶
| 2 December 2025 | LTTng 2.15.0 |