SYNOPSIS
--------
-Normal mode:
+Local mode:
[verse]
-*lttng* ['GENERAL OPTIONS'] *create* [option:--output='PATH' | option:--no-output]
- [option:--shm-path='PATH'] ['SESSION']
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *create* ['SESSION'] [option:--shm-path='PATH']
+ [option:--no-output | option:--output='PATH' | option:--set-url=file://'PATH']
+
+Network streaming mode:
+
+[verse]
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *create* ['SESSION'] [option:--shm-path='PATH']
+ (option:--set-url='URL' | option:--ctrl-url='URL' option:--data-url='URL')
Snapshot mode:
[verse]
-*lttng* ['GENERAL OPTIONS'] *create* option:--snapshot
- [option:--set-url='URL' | option:--ctrl-url='URL' option:--data-url='URL']
- [option:--shm-path='PATH'] ['SESSION']
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *create* ['SESSION'] option:--snapshot
+ [option:--shm-path='PATH'] [option:--set-url='URL' | option:--ctrl-url='URL' option:--data-url='URL']
Live mode:
[verse]
-*lttng* ['GENERAL OPTIONS'] *create* option:--live[='DELAYUS']
- [option:--set-url='URL' | option:--ctrl-url='URL' option:--data-url='URL']
- [option:--shm-path='PATH'] ['SESSION']
-
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *create* ['SESSION'] option:--live[='DELAYUS']
+ [option:--shm-path='PATH'] [option:--set-url='URL' | option:--ctrl-url='URL' option:--data-url='URL']
DESCRIPTION
-----------
user's home directory. This file contains the name of the current tracing
session. When creating a new tracing session with `lttng create`, the
current tracing session is set to this new tracing session. The
-linklttng:lttng-set-session(1) command can be used to set the current
+man:lttng-set-session(1) command can be used to set the current
tracing session without manually editing the `.lttngrc` file.
If 'SESSION' is omitted, a session name is automatically created having
NVRAM file system makes it possible to retrieve the latest recorded
trace data when the system reboots after a crash. To view the events
of ring buffer files after a system crash, use the
-linklttng:lttng-crash(1) utility.
+man:lttng-crash(1) utility.
-Tracing sessions are destroyed using the linklttng:lttng-destroy(1)
+Tracing sessions are destroyed using the man:lttng-destroy(1)
command.
Creation modes
~~~~~~~~~~~~~~
-There are three tracing session modes:
+There are four tracing session modes:
-Normal mode::
+[[local-mode]]Local mode::
Traces the local system and writes the trace to the local
file system. The option:--output option specifies the trace path.
- If omitted, the trace is written in the `$LTTNG_HOME/lttng-traces`
- directory (`$LTTNG_HOME` defaults to `$HOME`). The file system
- output can be disabled using the option:--no-output option.
+ Using option:--set-url=file://'PATH' is the equivalent of using
+ option:--output='PATH'. The file system output can be disabled using
+ the option:--no-output option.
++
+If none of the options mentioned above are used, then the trace is
+written locally in the `$LTTNG_HOME/lttng-traces` directory
+(`$LTTNG_HOME` defaults to `$HOME`).
+
+[[network-streaming-mode]]Network streaming mode::
+ Traces the local system and sends the trace over the network to
+ a listening relay daemon (see man:lttng-relayd(8)).
+ The option:--set-url, or option:--ctrl-url and option:--data-url
+ options set the trace output destination (see the
+ <<url-format,URL format>> section below).
-Snapshot mode::
+[[snapshot-mode]]Snapshot mode::
Traces the local system without writing the trace to the local file
system (implicit option:--no-output option). Channels are automatically
configured to be snapshot-ready on creation (see
- linklttng:lttng-enable-channel(1)). The linklttng:lttng-snapshot(1)
+ man:lttng-enable-channel(1)). The man:lttng-snapshot(1)
command is used to take snapshots of the current ring buffers.
The option:--set-url, or option:--ctrl-url and option:--data-url
options set the default snapshot output destination.
-Live mode::
+[[live-mode]]Live mode::
Traces the local system, sending trace data to an LTTng relay daemon
- over the network (see linklttng:lttng-relayd(8)). The
+ over the network (see man:lttng-relayd(8)). The
option:--set-url, or option:--ctrl-url and option:--data-url options
set the trace output destination. The live output URLs cannot use
- the `file://` protocol (see URL format below).
+ the `file://` protocol (see the <<url-format,URL format>>
+ section below).
[[url-format]]
URL format
~~~~~~~~~~
-The option:--set-url, option:--ctrl-url, and option:--data-url options
-specify URLs.
+The option:--set-url, option:--ctrl-url, and option:--data-url options'
+arguments are URLs.
The format of those URLs is one of:
file://'TRACEPATH'
'NETPROTO'://('HOST' | 'IPADDR')[:__CTRLPORT__[:__DATAPORT__]][/'TRACEPATH']
-The `file://` protocol targets the *local file system*.
+The `file://` protocol targets the *local file system* and can only
+be used as the option:--set-url option's argument when the session is
+created in <<local-mode,local>> or <<snapshot-mode,snapshot>> mode.
'TRACEPATH'::
Absolute path to trace files on the local file system.
-The other version is used for *network streaming*.
+The other version is available when the session is created in
+<<network-streaming-mode,network streaming>>,
+<<snapshot-mode,snapshot>>, or <<live-mode,live>> mode.
'NETPROTO'::
Network protocol, amongst:
+
-* `net`: TCP over IPv4; the default values of `<ctrl port>` and
- `<data port>` are resp. 5342 and 5343
-* `net6`: TCP over IPv6: same default ports as `net` protocol
-* `tcp`: same as `net` protocol; can only be used with the
- option:--ctrl-url and option:--data-url options together
-* `tcp6`: same as `net6` protocol; can only be used with the
- option:--ctrl-url and option:--data-url options together
+--
+`net`::
+ TCP over IPv4; the default values of 'CTRLPORT' and 'DATAPORT'
+ are respectively {default_network_control_port} and
+ {default_network_data_port}.
+
+`net6`::
+ TCP over IPv6: same default ports as the `net` protocol.
+
+`tcp`::
+ Same as the `net` protocol; can only be used with the
+ option:--ctrl-url and option:--data-url options together.
+
+`tcp6`::
+ Same as the `net6` protocol; can only be used with the
+ option:--ctrl-url and option:--data-url options together.
+--
('HOST' | 'IPADDR')::
Hostname or IP address (IPv6 address *must* be enclosed in brackets
'TRACEPATH'::
Path of trace files on the remote file system. This path is relative
to the base output directory set on the relay daemon side;
- see linklttng:lttng-relayd(8).
+ see man:lttng-relayd(8).
include::common-cmd-options-head.txt[]
-Mode
-~~~~
+Mode selection
+~~~~~~~~~~~~~~
option:--live[='DELAYUS']::
- Create the session in live mode. The optional 'DELAYUS' parameter,
- given in microseconds, is the maximum time the user can wait for
- the data to be flushed. This mode can be set with a network URL
- (options option:--set-url, or option:--ctrl-url and option:--data-url)
- and must have a relay daemon listening (see linklttng:lttng-relayd(8)).
+ Create the session in <<live-mode,live mode>>.
++
+The optional 'DELAYUS' parameter, given in microseconds, is the
+maximum time the user can wait for the data to be flushed. This mode
+can be set with a network URL (options option:--set-url, or
+option:--ctrl-url and option:--data-url) and must have a relay
+daemon listening (see man:lttng-relayd(8)).
+
-By default, 'DELAYUS' is 1000000 and the network URL is set to
-`net://127.0.0.1`.
+By default, 'DELAYUS' is {default_lttng_live_timer} and the network URL
+is set to `net://127.0.0.1`.
option:--snapshot::
- Create the session in snapshot mode. This is the equivalent of using
- the option:--no-output option and creating all the channels of this
- new tracing session in overwrite mode with an `mmap` output type.
+ Create the session in <<snapshot-mode,snapshot mode>>.
+ This is the equivalent of using the option:--no-output option and
+ creating all the channels of this new tracing session in overwrite
+ mode with an `mmap` output type.
Output
~~~~~~
option:--no-output::
- Do not output any trace data.
+ In <<local-mode,local mode>>, do not output any trace data.
-option:-o, option:--output='PATH'::
- Set trace output path to 'PATH'.
+option:-o 'PATH', option:--output='PATH'::
+ In <<local-mode,local mode>>, set trace output path to 'PATH'.
option:--shm-path='PATH'::
Create shared memory holding buffers at 'PATH'.
See the <<url-format,URL format>> section above for more information
about the syntax of the following options' 'URL' argument.
-option:-C, option:--ctrl-url='URL'::
+option:-C 'URL', option:--ctrl-url='URL'::
Set control path URL to 'URL' (must use option:--data-url option
also).
-option:-D, option:--data-url='URL'::
+option:-D 'URL', option:--data-url='URL'::
Set data path URL to 'URL' (must use option:--ctrl-url option
also).
-option:-U, option:--set-url='URL'::
+option:-U 'URL', option:--set-url='URL'::
Set URL destination of the trace data to 'URL'. It is persistent for
the session lifetime. This option sets both data
(option:--data-url option) and control (option:--ctrl-url option)
URLs at the same time.
++
+In <<local-mode,local>> mode, 'URL' must start with `file://` followed
+by the destination path on the local file system.
include::common-cmd-help-options.txt[]
SEE ALSO
--------
-linklttng:lttng-destroy(1),
-linklttng:lttng-set-session(1),
-linklttng:lttng(1)
+man:lttng-destroy(1),
+man:lttng-set-session(1),
+man:lttng(1)