1 .TH "LTTNG" "1" "February 05th, 2014" "" ""
4 lttng \(em LTTng 2.x tracer control command line tool
9 lttng [OPTIONS] <COMMAND>
13 The LTTng project aims at providing highly efficient tracing tools for Linux.
14 Its tracers help track down performance issues and debug problems
15 involving multiple concurrent processes and threads. Tracing across multiple
16 systems is also possible.
18 The \fBlttng\fP command line tool from the lttng-tools package is used to control
19 both kernel and user-space tracing. Every interaction with the tracer should
20 be done by this tool or by the liblttng-ctl library provided by the lttng-tools
23 LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry,
24 which allows you to interact with multiple tracers (kernel and user-space)
25 inside the same container, a tracing session. Traces can be gathered from the
26 kernel and/or instrumented applications (lttng-ust(3)). Aggregating and reading
27 those traces is done using the babeltrace(1) text viewer.
29 We introduce the notion of \fBtracing domains\fP which is essentially a type of
30 tracer (kernel, user space or JUL for now). In the future, we could see more
31 tracer like for instance an hypervisor. For some commands, you'll need to
32 specify on which domain the command operates (\-u, \-k or \-j). For instance,
33 the kernel domain must be specified when enabling a kernel event.
35 In order to trace the kernel, the session daemon needs to be running as root.
36 LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is
37 in that group can interact with the root session daemon and thus trace the
38 kernel. Session daemons can co-exist, meaning that you can have a session daemon
39 running as Alice that can be used to trace her applications along side with a
40 root daemon or even a Bob daemon. We highly recommend starting the session
41 daemon at boot time for stable and long term tracing.
43 All user-space applications instrumented with lttng-ust(3) will
44 automatically register to the session daemon. This feature gives you the
45 ability to list available traceable applications and tracepoints on a per user
46 basis. (See \fBlist\fP command).
50 This program follow the usual GNU command line syntax with long options starting with
51 two dashes. Below is a summary of the available options.
56 Show summary of possible options and commands.
58 .BR "\-v, \-\-verbose"
60 Three levels of verbosity are available which are triggered by putting additional v to
61 the option (\-vv or \-vvv)
64 Suppress all messages (even errors).
66 .BR "\-g, \-\-group NAME"
67 Set unix tracing group name. (default: tracing)
69 .BR "\-n, \-\-no-sessiond"
70 Don't automatically spawn a session daemon.
72 .BR "\-\-sessiond\-path PATH"
73 Set session daemon full binary path.
75 .BR "\-\-list\-options"
76 Simple listing of lttng options.
78 .BR "\-\-list\-commands"
79 Simple listing of lttng commands.
83 \fBadd-context\fP [OPTIONS]
85 Add context to event(s) and/or channel(s).
87 A context is basically extra information appended to a channel. For instance,
88 you could ask the tracer to add the PID information for all events in a
89 channel. You can also add performance monitoring unit counters (perf PMU) using
92 For example, this command will add the context information 'prio' and two perf
93 counters (hardware branch misses and cache misses), to all events in the trace
97 # lttng add-context \-k \-t prio \-t perf:branch-misses \\
101 Please take a look at the help (\-h/\-\-help) for a detailed list of available
104 If no channel is given (\-c), the context is added to all channels that were
105 already enabled. If the session has no channel, a default channel is created.
106 Otherwise the context will be added only to the given channel (\-c).
108 If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
115 Show summary of possible options and commands.
117 .BR "\-s, \-\-session NAME"
118 Apply on session name.
120 .BR "\-c, \-\-channel NAME"
121 Apply on channel name.
123 .BR "\-k, \-\-kernel"
124 Apply for the kernel tracer
126 .BR "\-u, \-\-userspace"
127 Apply for the user-space tracer
129 .BR "\-t, \-\-type TYPE"
130 Context type. You can repeat this option on the command line. Please
131 use "lttng add-context \-h" to list all available types.
136 \fBcalibrate\fP [OPTIONS]
138 Quantify LTTng overhead
140 The LTTng calibrate command can be used to find out the combined average
141 overhead of the LTTng tracer and the instrumentation mechanisms used. This
142 overhead can be calibrated in terms of time or using any of the PMU performance
143 counter available on the system.
145 For now, the only calibration implemented is that of the kernel function
146 instrumentation (kretprobes).
148 * Calibrate kernel function instrumentation
150 Let's use an example to show this calibration. We use an i7 processor with 4
151 general-purpose PMU registers. This information is available by issuing dmesg,
152 looking for "generic registers".
154 This sequence of commands will gather a trace executing a kretprobe hooked on
155 an empty function, gathering PMU counters LLC (Last Level Cache) misses
156 information (see lttng add-context \-\-help to see the list of available PMU
160 # lttng create calibrate-function
161 # lttng enable-event calibrate \-\-kernel \\
162 \-\-function lttng_calibrate_kretprobe
163 # lttng add-context \-\-kernel \-t perf:LLC-load-misses \\
164 \-t perf:LLC-store-misses \\
165 \-t perf:LLC-prefetch-misses
167 # for a in $(seq 1 10); do \\
168 lttng calibrate \-\-kernel \-\-function;
171 # babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\
175 The output from babeltrace can be saved to a text file and opened in a
176 spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between
177 consecutive "calibrate_entry" and "calibrate_return" events. Note that these
178 counters are per-CPU, so scheduling events would need to be present to account
179 for migration between CPU. Therefore, for calibration purposes, only events
180 staying on the same CPU must be considered.
182 The average result, for the i7, on 10 samples:
186 perf_LLC_load_misses: 5.0 0.577
187 perf_LLC_store_misses: 1.6 0.516
188 perf_LLC_prefetch_misses: 9.0 14.742
191 As we can notice, the load and store misses are relatively stable across runs
192 (their standard deviation is relatively low) compared to the prefetch misses.
193 We can conclude from this information that LLC load and store misses can be
194 accounted for quite precisely, but prefetches within a function seems to behave
195 too erratically (not much causality link between the code executed and the CPU
196 prefetch activity) to be accounted for.
202 Show summary of possible options and commands.
204 .BR "\-k, \-\-kernel"
205 Apply for the kernel tracer
207 .BR "\-u, \-\-userspace"
208 Apply for the user-space tracer
211 Dynamic function entry/return probe (default)
216 \fBcreate\fP [NAME] [OPTIONS]
218 Create tracing session.
220 A tracing session contains channel(s) which contains event(s). It is domain
221 agnostic, meaning that channels and events can be enabled for the
222 user-space tracer and/or the kernel tracer. It acts like a container
223 aggregating multiple tracing sources.
225 On creation, a \fB.lttngrc\fP file is created in your $HOME directory
226 containing the current session name. If NAME is omitted, a session name is
227 automatically created having this form: 'auto-yyyymmdd-hhmmss'.
229 If no \fB\-o, \-\-output\fP is specified, the traces will be written in
232 The $HOME environment variable can be overridden by defining the environment
233 variable LTTNG_HOME. This is useful when the user running the commands has
234 a non-writeable home directory.
236 The session name MUST NOT contain the character '/'.
242 Show summary of possible options and commands.
244 .BR "\-\-list-options"
245 Simple listing of options
247 .BR "\-o, \-\-output PATH"
248 Specify output path for traces
251 Traces will not be output
254 Set the session in snapshot mode. Created in no-output mode and uses the
255 URL, if one is specified, as the default snapshot output. Every channel will be set
256 in overwrite mode and with mmap output (splice not supported).
259 Set the session exclusively in live mode. The paremeter is the delay in micro
260 seconds before the data is flushed and streamed. The live mode allows you to
261 stream the trace and view it while it's being recorded by any tracer. For that,
262 you need a lttng-relayd and this session requires a network URL (\-U or
265 To read a live session, you can use babeltrace(1) or the live streaming
266 protocol in doc/live-reading-protocol.txt. Here is an example:
269 $ lttng-relayd -o /tmp/lttng
270 $ lttng create --live 200000 -U net://localhost
271 $ lttng enable-event -a --userspace
275 After the start, you'll be able to read the events while they are being
276 recorded in /tmp/lttng.
279 .BR "\-U, \-\-set-url=URL"
280 Set URL for the consumer output destination. It is persistent for the
281 session lifetime. Redo the command to change it. This will set both data
282 and control URL for network.
284 .BR "\-C, \-\-ctrl-url=URL"
285 Set control path URL. (Must use -D also)
287 .BR "\-D, \-\-data-url=URL"
288 Set data path URL. (Must use -C also)
290 Using these options, each API call can be controlled individually. For
291 instance, \-C does not enable the consumer automatically. You'll need the \-e
296 proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
298 Supported protocols are (proto):
301 Local filesystem full path.
305 This will use the default network transport layer which is TCP for both
306 control (PORT1) and data port (PORT2). The default ports are
307 respectively 5342 and 5343. Note that net[6]:// is not yet supported.
311 Can only be used with -C and -D together
313 NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732)
318 # lttng create -U net://192.168.1.42
320 Uses TCP and default ports for the given destination.
323 # lttng create -U net6://[fe80::f66d:4ff:fe53:d220]
325 Uses TCP, default ports and IPv6.
328 # lttng create s1 -U net://myhost.com:3229
330 Create session s1 and set its consumer to myhost.com on port 3229 for control.
335 \fBdestroy\fP [NAME] [OPTIONS]
337 Teardown tracing session
339 Free memory on the session daemon and tracer side. It's gone!
341 If NAME is omitted, the session name is taken from the .lttngrc file.
347 Show summary of possible options and commands.
352 .BR "\-\-list-options"
353 Simple listing of options
358 \fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
360 Enable tracing channel
362 To enable an event, you must enable both the event and the channel that
365 If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
368 Exactly one of \-k or -u must be specified.
370 It is important to note that if a certain type of buffers is used, the session
371 will be set with that type and all other subsequent channel needs to have the
374 Note that once the session has been started and enabled on the tracer side,
375 it's not possible anymore to enable a new channel for that session.
383 .BR "\-\-list-options"
384 Simple listing of options
386 .BR "\-s, \-\-session NAME"
387 Apply on session name
389 .BR "\-k, \-\-kernel"
390 Apply to the kernel tracer
392 .BR "\-u, \-\-userspace"
393 Apply to the user-space tracer
396 Discard event when subbuffers are full (default)
399 Flight recorder mode : overwrites events when subbuffers are full
401 .BR "\-\-subbuf-size SIZE"
402 Subbuffer size in bytes {+k,+M,+G}.
403 (default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096)
404 Rounded up to the next power of 2.
406 The minimum subbuffer size, for each tracer, is the max value between
407 the default above and the system page size. You can issue this command
408 to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP
410 .BR "\-\-num-subbuf NUM"
411 Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4,
412 metadata: 2) Rounded up to the next power of 2.
414 .BR "\-\-switch-timer USEC"
415 Switch subbuffer timer interval in µsec.
416 (default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0)
418 .BR "\-\-read-timer USEC"
419 Read timer interval in µsec.
420 (default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0)
422 .BR "\-\-output TYPE"
423 Channel output type. Possible values: mmap, splice
424 (default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap)
426 .BR "\-\-buffers-uid"
427 Use per UID buffer (\-u only). Buffers are shared between applications
428 that have the same UID.
430 .BR "\-\-buffers-pid"
431 Use per PID buffer (\-u only). Each application has its own buffers.
433 .BR "\-\-buffers-global"
434 Use shared buffer for the whole system (\-k only)
436 .BR "\-C, \-\-tracefile-size SIZE"
437 Maximum size of each tracefile within a stream (in bytes).
438 0 means unlimited. (default: 0)
440 .BR "\-W, \-\-tracefile-count COUNT"
441 Used in conjunction with \-C option, this will limit the number of files
442 created to the specified count. 0 means unlimited. (default: 0)
447 $ lttng enable-channel -k -C 4096 -W 32 chan1
449 For each stream, the maximum size of each trace file will be 4096 bytes and
450 there will be a maximum of 32 different files. The file count is appended after
451 the stream number as seen in the following example. The last trace file is
452 smaller than 4096 since it was not completely filled.
455 ~/lttng-traces/[...]/chan1_0_0 (4096)
456 ~/lttng-traces/[...]/chan1_0_1 (4096)
457 ~/lttng-traces/[...]/chan1_0_2 (3245)
458 ~/lttng-traces/[...]/chan1_1_0 (4096)
463 $ lttng enable-channel -k -C 4096
465 This will create trace files of 4096 bytes and will create new ones as long as
466 there is data available.
471 \fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]
475 A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is
476 omitted, a default channel named '\fBchannel0\fP' is created and the event is
477 added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default
478 channel already exists within the session, an error is returned. For the
479 user-space tracer, using \fB\-a, \-\-all\fP is the same as using the
482 If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
489 Show summary of possible options and commands.
491 .BR "\-\-list-options"
492 Simple listing of options
494 .BR "\-s, \-\-session NAME"
495 Apply on session name
497 .BR "\-c, \-\-channel NAME"
498 Apply on channel name
501 Enable all tracepoints and syscalls. This actually enables a single
504 .BR "\-k, \-\-kernel"
505 Apply for the kernel tracer
507 .BR "\-u, \-\-userspace"
508 Apply for the user-space tracer
511 Apply for Java application using Java Util Logging interface (JUL)
514 Tracepoint event (default). Userspace tracer supports wildcards at the end
515 of string. Don't forget to quote to deal with bash expansion.
522 .BR "\-\-loglevel NAME"
523 Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h).
524 For the JUL domain, the loglevel ranges are detailed with the \-\-help
525 option thus starting from SEVERE to FINEST.
527 .BR "\-\-loglevel-only NAME"
528 Tracepoint loglevel (only this loglevel).
529 The loglevel or loglevel-only options should be combined with a
530 tracepoint name or tracepoint wildcard.
532 .BR "\-\-probe (addr | symbol | symbol+offset)"
533 Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...)
534 or hexadecimal (0xNNN...)
536 .BR "\-\-function (addr | symbol | symbol+offset)"
537 Dynamic function entry/return probe. Addr and offset can be octal
538 (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...)
541 System call event. Enabling syscalls tracing (kernel tracer), you will
542 not be able to disable them with disable-event. This is a known
543 limitation. You can disable the entire channel to do the trick.
545 .BR "\-\-filter 'expression'"
546 Set a filter on a newly enabled event. Filter expression on event
547 fields and context. The event will be recorded if the filter's
548 expression evaluates to TRUE. Only specify on first activation of a
549 given event within a session.
550 Specifying a filter is only allowed when enabling events within a session before
551 tracing is started. If the filter fails to link with the event
552 within the traced domain, the event will be discarded.
553 Filtering is currently only implemented for the user-space tracer.
558 'intfield > 500 && intfield < 503'
559 '(strfield == "test" || intfield != 10) && intfield > 33'
560 'doublefield > 1.1 && intfield < 5.3'
563 Wildcards are allowed at the end of strings:
565 In string literals, the escape character is a '\\'. Use '\\*' for
566 the '*' character, and '\\\\' for the '\\' character sequence. Wildcard
567 matches any sequence of characters, including an empty sub-string
568 (matches 0 or more characters).
570 Context information can be used for filtering. The examples below shows
571 usage of context filtering on the process name (using a wildcard), process ID
572 range, and unique thread ID. The process and thread IDs of
573 running applications can be found under columns "PID" and "LWP" of the
577 '$ctx.procname == "demo*"'
578 '$ctx.vpid >= 4433 && $ctx.vpid < 4455'
583 .BR "\-x, \-\-exclude LIST"
584 Add exclusions to UST tracepoints:
585 Events that match any of the items in the comma-separated LIST are not
586 enabled, even if they match a wildcard definition of the event.
588 This option is also applicable with the \fB\-a, \-\-all\fP option,
589 in which case all UST tracepoints are enabled except the ones whose
590 names match any of the items in LIST.
595 \fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
597 Disable tracing channel
599 Disabling a channel disables the tracing of all of the channel's events. A channel
600 can be reenabled by calling \fBlttng enable-channel NAME\fP again.
602 If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
609 Show summary of possible options and commands.
611 .BR "\-\-list-options"
612 Simple listing of options
614 .BR "\-s, \-\-session NAME"
615 Apply on session name
617 .BR "\-k, \-\-kernel"
618 Apply for the kernel tracer
620 .BR "\-u, \-\-userspace"
621 Apply for the user-space tracer
626 \fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
628 Disable tracing event
630 The event, once disabled, can be re-enabled by calling \fBlttng enable-event
633 If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
636 If \fB\-c, \-\-channel\fP is omitted, the default channel name is used.
637 If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already
638 exists within the session, an error is returned.
644 Show summary of possible options and commands.
646 .BR "\-\-list-options"
647 Simple listing of options
649 .BR "\-s, \-\-session NAME"
650 Apply on session name
652 .BR "\-c, \-\-channel NAME"
653 Apply on channel name
655 .BR "\-a, \-\-all-events"
656 Disable all events. This does NOT disable "*" but rather every known
657 events of the session.
659 .BR "\-k, \-\-kernel"
660 Apply for the kernel tracer
662 .BR "\-u, \-\-userspace"
663 Apply for the user-space tracer
666 Apply for Java application using Java Util Logging interface (JUL)
671 \fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]]
673 List tracing session information.
675 With no arguments, it will list available tracing session(s).
677 With the session name, it will display the details of the session including
678 the trace file path, the associated channels and their state (activated
679 and deactivated), the activated events and more.
681 With \-k alone, it will list all available kernel events (except the system
683 With \-j alone, the available JUL event from registered application will be
684 list. The event corresponds to the Logger name in the Java JUL application.
685 With \-u alone, it will list all available user-space events from registered
686 applications. Here is an example of 'lttng list \-u':
689 PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello
690 ust_tests_hello:tptest_sighandler (type: tracepoint)
691 ust_tests_hello:tptest (type: tracepoint)
694 You can now enable any event listed by using the name :
695 \fBust_tests_hello:tptest\fP.
701 Show summary of possible options and commands.
703 .BR "\-\-list-options"
704 Simple listing of options
706 .BR "\-k, \-\-kernel"
709 .BR "\-u, \-\-userspace"
710 Select user-space domain.
713 Apply for Java application using JUL
715 .BR "\-f, \-\-fields"
722 .BR "\-c, \-\-channel NAME"
723 List details of a channel
725 .BR "\-d, \-\-domain"
726 List available domain(s)
731 \fBset-session\fP NAME [OPTIONS]
733 Set current session name
735 Will change the session name in the .lttngrc file.
741 Show summary of possible options and commands.
743 .BR "\-\-list-options"
744 Simple listing of options
749 \fBsnapshot\fP [OPTIONS] ACTION
751 Snapshot command for LTTng session.
757 Show summary of possible options and commands.
759 .BR "\-\-list-options"
760 Simple listing of options
766 \fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL>
768 Setup and add an snapshot output for a session. Output are the destination
769 where the snapshot will be sent. Only one output is permitted. To change it,
770 you'll need to delete it and add back the new one.
773 \fBdel-output\fP ID | NAME [-s <NAME>]
775 Delete an output for a session using the ID. You can either specify the
776 output's ID that can be found with list-output or the name.
779 \fBlist-output\fP [-s <NAME>]
781 List the output of a session. Attributes of the output are printed.
784 \fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>]
786 Snapshot a session's buffer(s) for all domains. If an URL is specified, it is
787 used instead of a previously added output. Specifying only a name or/and a max
788 size will override the current output values. For instance, you can record a
789 snapshot with a custom maximum size or with a different name.
792 $ lttng snapshot add-output -n mysnapshot file:///data/snapshot
794 $ lttng snapshot record -n new_name_snapshot
797 The above will create a snapshot in /data/snapshot/new_name_snapshot* directory
798 rather then in mysnapshot*/
801 .B DETAILED ACTION OPTIONS
804 .BR "\-s, \-\-session NAME"
805 Apply to session name.
807 .BR "\-n, \-\-name NAME"
808 Name of the snapshot's output.
810 .BR "\-m, \-\-max-size SIZE"
811 Maximum size in bytes of the snapshot. The maxium size does not include the
812 metadata file. Human readable format is accepted: {+k,+M,+G}. For instance,
815 .BR "\-C, \-\-ctrl-url URL"
816 Set control path URL. (Must use -D also)
818 .BR "\-D, \-\-data-url URL"
819 Set data path URL. (Must use -C also)
824 \fBstart\fP [NAME] [OPTIONS]
828 It will start tracing for all tracers for a specific tracing session.
829 If NAME is omitted, the session name is taken from the .lttngrc file.
835 Show summary of possible options and commands.
837 .BR "\-\-list-options"
838 Simple listing of options
843 \fBstop\fP [NAME] [OPTIONS]
847 It will stop tracing for all tracers for a specific tracing session. Before
848 returning, the command checks for data availability meaning that it will wait
849 until the trace is readable for the session. Use \-\-no-wait to avoid this
852 If NAME is omitted, the session name is taken from the .lttngrc file.
858 Show summary of possible options and commands.
860 .BR "\-\-list-options"
861 Simple listing of options
863 Don't wait for data availability.
870 Show version information
876 Show summary of possible options and commands.
878 .BR "\-\-list-options"
879 Simple listing of options
884 \fBview\fP [SESSION_NAME] [OPTIONS]
886 View traces of a tracing session. By default, the babeltrace viewer
887 will be used for text viewing. If SESSION_NAME is omitted, the session
888 name is taken from the .lttngrc file.
896 .BR "\-\-list-options"
897 Simple listing of options
899 .BR "\-t, \-\-trace-path PATH"
900 Trace directory path for the viewer
902 .BR "\-e, \-\-viewer CMD"
903 Specify viewer and/or options to use This will completely override the
904 default viewers so please make sure to specify the full command. The
905 trace directory path of the session will be appended at the end to the
911 This section explains the JUL domain (\-j, \-\-jul) where JUL stands for Java
912 Util Logging. You can use that feature by using the \fBliblttng-ust-jul.so\fP
913 from the lttng-ust(3) project.
915 The LTTng Java Agent uses JNI to link the UST tracer to the Java application
916 that uses the agent. Thus, it behaves similarly to the UST domain (\-u). When
917 enabling events with the JUL domain, you enable a Logger name that will then be
918 mapped to a default UST tracepoint called \fBlttng_jul:jul_event\fP in the
919 \fBlttng_jul_channel\fP. Using the lttng-ctl API, any JUL events must use the
920 tracepoint event type (same as \-\-tracepoint).
922 Because of the default immutable channel (\fBlttng_jul_channel\fP), the
923 \fBenable-channel\fP command CAN NOT be used with the JUL domain thus not
924 having any \-j option.
926 For JUL event, loglevels are supported with the JUL ABI values. Use \fBlttng
927 enable-event \-h\fP to list them. Wildcards are NOT supported except the "*"
928 meaning all events (same as \-a).
930 Exactly like the UST domain, if the Java application has the same UID as you,
931 you can trace it. Same goes for the tracing group accessing root applications.
933 Finally, you can list every Logger name that are available from JUL registered
934 applications to the session daemon by using \fBlttng list \-j\fP.
936 Here is an example on how to use this domain.
941 $ lttng create aSession
942 $ lttng enable-event -s aSession -j MyCustomLoggerName
946 More information can be found in the lttng-ust documentation, see
947 java-util-logging.txt
952 On success 0 is returned and a positive value on error. Value of 1 means a command
953 error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that
954 something went wrong during the command.
956 Any other value above 10, please refer to
957 .BR "<lttng/lttng-error.h>"
958 for a detailed list or use lttng_strerror() to get a human readable string of
962 .SH "ENVIRONMENT VARIABLES"
965 Note that all command line options override environment variables.
969 .IP "LTTNG_SESSIOND_PATH"
970 Allows one to specify the full session daemon binary path to lttng command line
971 tool. You can also use \-\-sessiond-path option having the same effect.
977 .BR lttng-sessiond(8),
983 If you encounter any issues or usability problem, please report it on our
984 mailing list <lttng-dev@lists.lttng.org> to help improve this project or
985 at https://bugs.lttng.org which is a bugtracker.
991 lttng is distributed under the GNU General Public License version 2. See the file
994 A Web site is available at http://lttng.org for more information on the LTTng
997 You can also find our git tree at http://git.lttng.org.
999 Mailing lists for support and development: <lttng-dev@lists.lttng.org>.
1001 You can find us on IRC server irc.oftc.net (OFTC) in #lttng.
1006 Thanks to Yannick Brosseau without whom this project would never have been so
1007 lean and mean! Also thanks to the Ericsson teams working on tracing which
1008 helped us greatly with detailed bug reports and unusual test cases.
1010 Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA
1011 maintainer) and Jon Bernard for our Debian packages.
1013 Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de
1014 Montreal for the LTTng journey.
1019 lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and
1020 David Goulet. More people have since contributed to it. It is currently
1021 maintained by David Goulet <dgoulet@efficios.com>.