lttng-disable-event - Man Page

Disable LTTng recording event rules

Synopsis

Disable one or more recording event rules matching Linux kernel events:

lttng [GENERAL OPTIONS] disable-event --kernel
      [--tracepoint | --syscall | --probe | --function]
      (--all-events | NAME[,NAME]...)
      [--session=SESSION] [--channel=CHANNEL]

Disable one or more recording event rules matching user space tracepoint or Java/Python logging events:

lttng [GENERAL OPTIONS] disable-event
      (--userspace | --jul | --log4j | --python) [--tracepoint]
      (--all-events | NAME[,NAME]...)
      [--session=SESSION] [--channel=CHANNEL]

Description

The lttng disable-event command disables one or more enabled recording event rules previously created with the lttng-enable-event(1) command which belong to:

With the --session=SESSION option

The recording session named SESSION.

Without the --session option

The current recording session (see lttng-concepts(7) to learn more about the current recording session).

With the --channel=CHANNEL option

The channel named CHANNEL.

Without the --channel option

The channel named channel0.

If there’s more than one channel for the selected recording session and domain, the disable-event command fails.

See lttng-concepts(7) to learn more about recording event rules.

As of LTTng 2.13.7, the disable-event command can only find recording event rules to disable by their instrumentation point type and event name conditions. Therefore, you cannot disable recording event rules having a specific instrumentation point log level condition, for example.

With the --kernel option and no instrumentation point type condition option, the disable-event command disables one or more Linux kernel recording event rules regardless of their instrumentation point type.

List the recording event rules of a given recording session and/or channel with the lttng-list(1) command.

Without the --all-events option, the disable-event command disables one recording event rule per NAME argument. NAME is the exact event name condition pattern of the recording event rule to disable, as listed in the output of lttng list (see lttng-list(1)).

You may disable an enabled recording event rule regardless of the activity (started or stopped) of its recording session (see lttng-start(1) and lttng-stop(1)).

See the “Examples” section below for usage examples.

Options

See lttng(1) for GENERAL OPTIONS.

Tracing domain

One of:

-j,  --jul

Disable recording event rules in the java.util.logging (JUL) domain.

-k,  --kernel

Disable recording event rules in the Linux kernel domain.

-l,  --log4j

Disable recording event rules in the Apache log4j domain.

-p,  --python

Disable recording event rules in the Python domain.

-u,  --userspace

Disable recording event rules in the user space tracing domain.

Recording target

-c CHANNEL, --channel=CHANNEL

Disable recording event rules attached to the channel named CHANNEL instead of channel0.

-s SESSION, --session=SESSION

Disable recording event rules in the recording session named SESSION instead of the current recording session.

Instrumentation point type condition

At most one of:

--function

Only disable recording event rules which match Linux kretprobe events.

Only available with the --kernel option.

--probe

Only disable recording event rules which match Linux kprobe events.

Only available with the --kernel option.

--syscall

Only disable recording event rules which match Linux system call events.

Only available with the --kernel option.

--tracepoint

Only disable recording event rules which match:

With the --kernel or --userspace option

LTTng tracepoint events.

With the --jul, --log4j, or --python option

Logging events.

Event name condition

-a,  --all-events

Disable recording event rules regardless of their event name condition.

Program information

-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.

Exit Status

0

Success

1

Command error

2

Undefined command

3

Fatal error

4

Command warning (something went wrong during the command)

Environment

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.

Files

$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)).

/usr/local/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.

Examples

Example 1. Disable all Linux kernel tracepoint recording event rules in the default channel of the current recording session.

See the --all-events option.

$ lttng disable-event --kernel --tracepoint --all-events

Example 2. Disable specific Apache log4j recording event rules in the default channel of a specific recording session.

See the --session option.

$ lttng disable-event --session=my-session --log4j \
                      MySingleton,MyProxy,MyFacade

Example 3. Disable all user space recording event rules in a specific channel of the current recording session.

See the --channel option.

$ lttng disable-event --channel=my-channel --userspace \
                      --all-events

Example 4. Disable specific Linux kernel system call recording event rules in the default channel of the current recording session.

$ lttng disable-event --kernel --syscall pipe2,eventfd

Resources

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

lttng(1), lttng-enable-event(1), lttng-list(1), lttng-concepts(7)

Referenced By

lttng(1), lttng-concepts(7), lttng-enable-event(1).

14 June 2021 LTTng 2.13.7 LTTng Manual