Update man page with LOG4J information
[lttng-tools.git] / doc / man / lttng.1
CommitLineData
516f6cbe 1.TH "LTTNG" "1" "May 13th, 2014" "" ""
6991b181
DG
2
3.SH "NAME"
c5db699c 4lttng \(em LTTng 2.x tracer control command line tool
6991b181
DG
5
6.SH "SYNOPSIS"
7
8.PP
6991b181 9lttng [OPTIONS] <COMMAND>
6991b181
DG
10.SH "DESCRIPTION"
11
12.PP
13The LTTng project aims at providing highly efficient tracing tools for Linux.
e256d661 14Its tracers help track down performance issues and debug problems
6991b181
DG
15involving multiple concurrent processes and threads. Tracing across multiple
16systems is also possible.
17
fa072eae 18The \fBlttng\fP command line tool from the lttng-tools package is used to control
e256d661
JG
19both kernel and user-space tracing. Every interaction with the tracer should
20be done by this tool or by the liblttng-ctl library provided by the lttng-tools
6991b181
DG
21package.
22
23LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry,
50a3b92a 24which allows you to interact with multiple tracers (kernel and user-space)
6991b181
DG
25inside the same container, a tracing session. Traces can be gathered from the
26kernel and/or instrumented applications (lttng-ust(3)). Aggregating and reading
27those traces is done using the babeltrace(1) text viewer.
28
50a3b92a 29We introduce the notion of \fBtracing domains\fP which is essentially a type of
999ee001
DG
30tracer (kernel, user space, JUL or LOG4J for now). In the future, we could see
31more tracer like for instance an hypervisor. For some commands, you'll need to
acf47627
DG
32specify on which domain the command operates (\-u, \-k or \-j). For instance,
33the kernel domain must be specified when enabling a kernel event.
50a3b92a 34
6991b181
DG
35In order to trace the kernel, the session daemon needs to be running as root.
36LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is
37in that group can interact with the root session daemon and thus trace the
e256d661 38kernel. Session daemons can co-exist, meaning that you can have a session daemon
fa072eae 39running as Alice that can be used to trace her applications along side with a
e256d661 40root daemon or even a Bob daemon. We highly recommend starting the session
6991b181
DG
41daemon at boot time for stable and long term tracing.
42
274d6c5d
DG
43Each user-space application instrumented with lttng-ust(3) will automatically
44register with the root session daemon and its user session daemon. This allows
45each daemon to list the available traceable applications and tracepoints at any
46given moment (See the \fBlist\fP command).
6991b181
DG
47.SH "OPTIONS"
48
49.PP
50This program follow the usual GNU command line syntax with long options starting with
51two dashes. Below is a summary of the available options.
52.PP
53
54.TP
c9e32613 55.BR "\-h, \-\-help"
6991b181
DG
56Show summary of possible options and commands.
57.TP
c9e32613 58.BR "\-v, \-\-verbose"
6991b181 59Increase verbosity.
d829b38c 60Three levels of verbosity are available which are triggered by putting additional v to
fa072eae 61the option (\-vv or \-vvv)
6991b181 62.TP
c9e32613 63.BR "\-q, \-\-quiet"
6991b181
DG
64Suppress all messages (even errors).
65.TP
c9e32613 66.BR "\-g, \-\-group NAME"
6991b181
DG
67Set unix tracing group name. (default: tracing)
68.TP
c9e32613 69.BR "\-n, \-\-no-sessiond"
6991b181
DG
70Don't automatically spawn a session daemon.
71.TP
391b9c72 72.BR "\-\-sessiond\-path PATH"
6991b181
DG
73Set session daemon full binary path.
74.TP
c9e32613 75.BR "\-\-list\-options"
6991b181
DG
76Simple listing of lttng options.
77.TP
c9e32613 78.BR "\-\-list\-commands"
6991b181 79Simple listing of lttng commands.
ed43168a
JRJ
80.TP
81.BR "\-m, \-\-mi TYPE
82Machine interface
83
84TYPE supported: XML
85
86Machine interface (MI) mode converts the traditional pretty printing to a
87machine output syntax. MI mode provides a format change-resistant way to access
88information generated via the lttng command line.
89
90When using MI mode, the data is printed on \fBstdout\fP. Error and warning are
91printed on \fBstderr\fP with the pretty print default format.
92
93If any errors occur during the execution of a command, the return value of the
94command will be different than zero. In this case, lttng does NOT guarantee the
95syntax and data validity of the generated MI output.
96
97For XML output type, a schema definition (XSD) file used for validation can be
98found under src/common/mi_lttng.xsd
99
6991b181
DG
100.SH "COMMANDS"
101
812a5eb7 102.PP
ee2758e5 103\fBadd-context\fP [OPTIONS]
812a5eb7 104.RS
6991b181
DG
105Add context to event(s) and/or channel(s).
106
391b9c72
DG
107A context is basically extra information appended to a channel. For instance,
108you could ask the tracer to add the PID information for all events in a
109channel. You can also add performance monitoring unit counters (perf PMU) using
aa3514e9 110the perf kernel API.
6991b181 111
aa3514e9
MD
112For example, this command will add the context information 'prio' and two per-CPU
113perf counters (hardware branch misses and cache misses), to all events in the trace
6991b181
DG
114data output:
115
812a5eb7 116.nf
aa3514e9
MD
117# lttng add-context \-k \-t prio \-t perf:cpu:branch-misses \\
118 \-t perf:cpu:cache-misses
812a5eb7 119.fi
6991b181 120
c9e32613 121Please take a look at the help (\-h/\-\-help) for a detailed list of available
6991b181
DG
122contexts.
123
aa3514e9
MD
124Perf counters are available as per-CPU ("perf:cpu:...") and per-thread
125("perf:thread:...") counters. Currently, per-CPU counters can only be
126used with the kernel tracing domain, and per-thread counters can only be
127used with the UST tracing domain.
128
bd337b98
DG
129If no channel is given (\-c), the context is added to all channels that were
130already enabled. If the session has no channel, a default channel is created.
31ea4846 131Otherwise the context will be added only to the given channel (\-c).
6991b181 132
c9e32613 133If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 134file.
6991b181
DG
135
136.B OPTIONS:
137
812a5eb7
MD
138.TP
139.BR "\-h, \-\-help"
140Show summary of possible options and commands.
141.TP
142.BR "\-s, \-\-session NAME"
143Apply on session name.
144.TP
145.BR "\-c, \-\-channel NAME"
146Apply on channel name.
147.TP
148.BR "\-k, \-\-kernel"
149Apply for the kernel tracer
150.TP
151.BR "\-u, \-\-userspace"
152Apply for the user-space tracer
153.TP
154.BR "\-t, \-\-type TYPE"
155Context type. You can repeat this option on the command line. Please
156use "lttng add-context \-h" to list all available types.
157.RE
158.PP
6991b181 159
22019883
MD
160.PP
161\fBcalibrate\fP [OPTIONS]
162.RS
6991b181
DG
163Quantify LTTng overhead
164
165The LTTng calibrate command can be used to find out the combined average
166overhead of the LTTng tracer and the instrumentation mechanisms used. This
167overhead can be calibrated in terms of time or using any of the PMU performance
168counter available on the system.
169
170For now, the only calibration implemented is that of the kernel function
171instrumentation (kretprobes).
172
173* Calibrate kernel function instrumentation
174
175Let's use an example to show this calibration. We use an i7 processor with 4
176general-purpose PMU registers. This information is available by issuing dmesg,
177looking for "generic registers".
178
179This sequence of commands will gather a trace executing a kretprobe hooked on
180an empty function, gathering PMU counters LLC (Last Level Cache) misses
c9e32613 181information (see lttng add-context \-\-help to see the list of available PMU
6991b181
DG
182counters).
183
22019883 184.nf
6991b181 185# lttng create calibrate-function
22019883
MD
186# lttng enable-event calibrate \-\-kernel \\
187 \-\-function lttng_calibrate_kretprobe
aa3514e9
MD
188# lttng add-context \-\-kernel \-t perf:cpu:LLC-load-misses \\
189 \-t perf:cpu:LLC-store-misses \\
190 \-t perf:cpu:LLC-prefetch-misses
6991b181
DG
191# lttng start
192# for a in $(seq 1 10); do \\
c9e32613 193 lttng calibrate \-\-kernel \-\-function;
6991b181
DG
194 done
195# lttng destroy
22019883
MD
196# babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\
197 | tail \-n 1)
198.fi
6991b181
DG
199
200The output from babeltrace can be saved to a text file and opened in a
201spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between
202consecutive "calibrate_entry" and "calibrate_return" events. Note that these
203counters are per-CPU, so scheduling events would need to be present to account
204for migration between CPU. Therefore, for calibration purposes, only events
205staying on the same CPU must be considered.
206
207The average result, for the i7, on 10 samples:
208
22019883 209.nf
6991b181
DG
210 Average Std.Dev.
211perf_LLC_load_misses: 5.0 0.577
212perf_LLC_store_misses: 1.6 0.516
213perf_LLC_prefetch_misses: 9.0 14.742
22019883 214.fi
6991b181
DG
215
216As we can notice, the load and store misses are relatively stable across runs
217(their standard deviation is relatively low) compared to the prefetch misses.
218We can conclude from this information that LLC load and store misses can be
219accounted for quite precisely, but prefetches within a function seems to behave
220too erratically (not much causality link between the code executed and the CPU
221prefetch activity) to be accounted for.
6991b181
DG
222
223.B OPTIONS:
224
22019883
MD
225.TP
226.BR "\-h, \-\-help"
227Show summary of possible options and commands.
228.TP
229.BR "\-k, \-\-kernel"
230Apply for the kernel tracer
231.TP
232.BR "\-u, \-\-userspace"
233Apply for the user-space tracer
234.TP
235.BR "\-\-function"
236Dynamic function entry/return probe (default)
237.RE
238.PP
6991b181 239
ee2758e5 240.PP
feb3ca56 241\fBcreate\fP [NAME] [OPTIONS]
ee2758e5 242.RS
6991b181
DG
243Create tracing session.
244
245A tracing session contains channel(s) which contains event(s). It is domain
e256d661 246agnostic, meaning that channels and events can be enabled for the
6991b181
DG
247user-space tracer and/or the kernel tracer. It acts like a container
248aggregating multiple tracing sources.
249
250On creation, a \fB.lttngrc\fP file is created in your $HOME directory
251containing the current session name. If NAME is omitted, a session name is
fa072eae 252automatically created having this form: 'auto-yyyymmdd-hhmmss'.
6991b181 253
c9e32613 254If no \fB\-o, \-\-output\fP is specified, the traces will be written in
6991b181 255$HOME/lttng-traces.
feb0f3e5
AM
256
257The $HOME environment variable can be overridden by defining the environment
258variable LTTNG_HOME. This is useful when the user running the commands has
259a non-writeable home directory.
6991b181 260
1c1c3634
DG
261The session name MUST NOT contain the character '/'.
262
6991b181
DG
263.B OPTIONS:
264
ee2758e5
MD
265.TP
266.BR "\-h, \-\-help"
267Show summary of possible options and commands.
268.TP
269.BR "\-\-list-options"
270Simple listing of options
271.TP
272.BR "\-o, \-\-output PATH"
273Specify output path for traces
274.TP
96fe6b8d
DG
275.BR "\-\-no-output"
276Traces will not be output
277.TP
ee2758e5 278.BR "\-\-snapshot"
96fe6b8d
DG
279Set the session in snapshot mode. Created in no-output mode and uses the
280URL, if one is specified, as the default snapshot output. Every channel will be set
ee2758e5 281in overwrite mode and with mmap output (splice not supported).
0794f51b 282.TP
d73c5802 283.BR "\-\-live [USEC]"
eb82f91d 284Set the session exclusively in live mode. The parameter is the delay in micro
0794f51b
DG
285seconds before the data is flushed and streamed. The live mode allows you to
286stream the trace and view it while it's being recorded by any tracer. For that,
287you need a lttng-relayd and this session requires a network URL (\-U or
d73c5802
DG
288\-C/\-D). If no USEC nor URL is provided, the default is to use a timer value
289set to 1000000 and the network URL set to net://127.0.0.1.
0794f51b
DG
290
291To read a live session, you can use babeltrace(1) or the live streaming
292protocol in doc/live-reading-protocol.txt. Here is an example:
293
294.nf
295$ lttng-relayd -o /tmp/lttng
296$ lttng create --live 200000 -U net://localhost
297$ lttng enable-event -a --userspace
298$ lttng start
299.fi
300
301After the start, you'll be able to read the events while they are being
302recorded in /tmp/lttng.
6b8f2e64 303
ee2758e5
MD
304.TP
305.BR "\-U, \-\-set-url=URL"
306Set URL for the consumer output destination. It is persistent for the
307session lifetime. Redo the command to change it. This will set both data
308and control URL for network.
309.TP
310.BR "\-C, \-\-ctrl-url=URL"
311Set control path URL. (Must use -D also)
312.TP
313.BR "\-D, \-\-data-url=URL"
314Set data path URL. (Must use -C also)
315.PP
6b8f2e64
DG
316Using these options, each API call can be controlled individually. For
317instance, \-C does not enable the consumer automatically. You'll need the \-e
318option for that.
319
785d2d0d
DG
320.B URL FORMAT:
321
322proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
323
324Supported protocols are (proto):
ee2758e5
MD
325.TP
326.BR "file://..."
327Local filesystem full path.
785d2d0d 328
ee2758e5
MD
329.TP
330.BR "net://..."
331This will use the default network transport layer which is TCP for both
332control (PORT1) and data port (PORT2). The default ports are
333respectively 5342 and 5343. Note that net[6]:// is not yet supported.
785d2d0d 334
ee2758e5
MD
335.TP
336.BR "tcp[6]://..."
337Can only be used with -C and -D together
785d2d0d
DG
338
339NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732)
6b8f2e64
DG
340
341.B EXAMPLES:
342
ee2758e5 343.nf
6b8f2e64 344# lttng create -U net://192.168.1.42
ee2758e5 345.fi
6b8f2e64
DG
346Uses TCP and default ports for the given destination.
347
ee2758e5 348.nf
6b8f2e64 349# lttng create -U net6://[fe80::f66d:4ff:fe53:d220]
ee2758e5 350.fi
6b8f2e64
DG
351Uses TCP, default ports and IPv6.
352
ee2758e5 353.nf
6b8f2e64 354# lttng create s1 -U net://myhost.com:3229
6991b181 355.fi
ee2758e5
MD
356Create session s1 and set its consumer to myhost.com on port 3229 for control.
357.RE
358.PP
6991b181 359
f2b14ef1
MD
360.PP
361\fBdestroy\fP [NAME] [OPTIONS]
362.RS
6991b181
DG
363Teardown tracing session
364
365Free memory on the session daemon and tracer side. It's gone!
366
367If NAME is omitted, the session name is taken from the .lttngrc file.
6991b181
DG
368
369.B OPTIONS:
370
f2b14ef1
MD
371.TP
372.BR "\-h, \-\-help"
373Show summary of possible options and commands.
374.TP
375.BR "\-a, \-\-all"
376Destroy all sessions
377.TP
378.BR "\-\-list-options"
379Simple listing of options
380.RE
381.PP
6991b181 382
05be3802
MD
383.PP
384\fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
385.RS
6991b181
DG
386Enable tracing channel
387
004f3466
DG
388To enable an event, you must enable both the event and the channel that
389contains it.
b883c01b 390
c9e32613 391If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 392file.
7972aab2 393
05be3802
MD
394Exactly one of \-k or -u must be specified.
395
7972aab2 396It is important to note that if a certain type of buffers is used, the session
bd337b98 397will be set with that type and all other subsequent channel needs to have the
7972aab2 398same type.
bd337b98 399
d2f11c4a
DG
400Note that once the session has been started and enabled on the tracer side,
401it's not possible anymore to enable a new channel for that session.
6991b181
DG
402
403.B OPTIONS:
404
05be3802
MD
405.TP
406.BR "\-h, \-\-help"
407Show this help
408.TP
409.BR "\-\-list-options"
410Simple listing of options
411.TP
412.BR "\-s, \-\-session NAME"
413Apply on session name
414.TP
415.BR "\-k, \-\-kernel"
416Apply to the kernel tracer
417.TP
418.BR "\-u, \-\-userspace"
419Apply to the user-space tracer
420.TP
421.BR "\-\-discard"
422Discard event when subbuffers are full (default)
423.TP
424.BR "\-\-overwrite"
33fbd469
DG
425Flight recorder mode: overwrites events when subbuffers are full. The
426number of subbuffer must be 2 or more.
05be3802
MD
427.TP
428.BR "\-\-subbuf-size SIZE"
429Subbuffer size in bytes {+k,+M,+G}.
430(default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096)
431Rounded up to the next power of 2.
432
433The minimum subbuffer size, for each tracer, is the max value between
434the default above and the system page size. You can issue this command
435to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP
436.TP
437.BR "\-\-num-subbuf NUM"
438Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4,
439metadata: 2) Rounded up to the next power of 2.
440.TP
441.BR "\-\-switch-timer USEC"
442Switch subbuffer timer interval in µsec.
443(default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0)
444.TP
445.BR "\-\-read-timer USEC"
446Read timer interval in µsec.
447(default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0)
448.TP
449.BR "\-\-output TYPE"
450Channel output type. Possible values: mmap, splice
451(default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap)
452.TP
453.BR "\-\-buffers-uid"
454Use per UID buffer (\-u only). Buffers are shared between applications
455that have the same UID.
456.TP
457.BR "\-\-buffers-pid"
458Use per PID buffer (\-u only). Each application has its own buffers.
459.TP
460.BR "\-\-buffers-global"
461Use shared buffer for the whole system (\-k only)
462.TP
463.BR "\-C, \-\-tracefile-size SIZE"
464Maximum size of each tracefile within a stream (in bytes).
4650 means unlimited. (default: 0)
c0684a0d 466Note: traces generated with this option may inaccurately report
a10f04ad 467discarded events as of CTF 1.8.
05be3802
MD
468.TP
469.BR "\-W, \-\-tracefile-count COUNT"
470Used in conjunction with \-C option, this will limit the number of files
471created to the specified count. 0 means unlimited. (default: 0)
1624d5b7
JD
472
473.B EXAMPLES:
474
05be3802
MD
475.nf
476$ lttng enable-channel -k -C 4096 -W 32 chan1
477.fi
e256d661 478For each stream, the maximum size of each trace file will be 4096 bytes and
cea28771 479there will be a maximum of 32 different files. The file count is appended after
1624d5b7
JD
480the stream number as seen in the following example. The last trace file is
481smaller than 4096 since it was not completely filled.
482
05be3802 483.nf
1624d5b7
JD
484 ~/lttng-traces/[...]/chan1_0_0 (4096)
485 ~/lttng-traces/[...]/chan1_0_1 (4096)
486 ~/lttng-traces/[...]/chan1_0_2 (3245)
487 ~/lttng-traces/[...]/chan1_1_0 (4096)
488 ...
05be3802 489.fi
1624d5b7 490
05be3802
MD
491.nf
492$ lttng enable-channel -k -C 4096
493.fi
1624d5b7
JD
494This will create trace files of 4096 bytes and will create new ones as long as
495there is data available.
05be3802
MD
496.RE
497.PP
6991b181 498
6a240cd9
MD
499.PP
500\fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]
501.RS
6991b181
DG
502Enable tracing event
503
c9e32613 504A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is
6991b181 505omitted, a default channel named '\fBchannel0\fP' is created and the event is
85076754
MD
506added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default
507channel already exists within the session, an error is returned. For the
508user-space tracer, using \fB\-a, \-\-all\fP is the same as using the
509wildcard "*".
6991b181 510
c9e32613 511If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 512file.
6991b181
DG
513
514.B OPTIONS:
515
6a240cd9
MD
516.TP
517.BR "\-h, \-\-help"
518Show summary of possible options and commands.
519.TP
520.BR "\-\-list-options"
521Simple listing of options
522.TP
523.BR "\-s, \-\-session NAME"
524Apply on session name
525.TP
526.BR "\-c, \-\-channel NAME"
527Apply on channel name
528.TP
529.BR "\-a, \-\-all"
e256d661 530Enable all tracepoints and syscalls. This actually enables a single
6a240cd9
MD
531wildcard event "*".
532.TP
533.BR "\-k, \-\-kernel"
534Apply for the kernel tracer
535.TP
536.BR "\-u, \-\-userspace"
537Apply for the user-space tracer
538.TP
bed69e7d
DG
539.BR "\-j, \-\-jul"
540Apply for Java application using Java Util Logging interface (JUL)
541.TP
222e4eab
DG
542.BR "\-l, \-\-log4j"
543Apply for Java application using LOG4J
544.TP
6a240cd9 545.BR "\-\-tracepoint"
e256d661 546Tracepoint event (default). Userspace tracer supports wildcards at the end
6a240cd9
MD
547of string. Don't forget to quote to deal with bash expansion.
548e.g.:
6991b181 549.nf
6991b181
DG
550 "*"
551 "app_component:na*"
6991b181 552.fi
6a240cd9
MD
553.TP
554.BR "\-\-loglevel NAME"
555Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h).
f9e8873b
DG
556For the JUL domain, the loglevel ranges are detailed with the \-\-help
557option thus starting from SEVERE to FINEST.
999ee001
DG
558For the LOG4J domain, loglevels range from FATAL to TRACE which are also
559detailed in the help.
6a240cd9
MD
560.TP
561.BR "\-\-loglevel-only NAME"
562Tracepoint loglevel (only this loglevel).
563The loglevel or loglevel-only options should be combined with a
564tracepoint name or tracepoint wildcard.
565.TP
566.BR "\-\-probe (addr | symbol | symbol+offset)"
567Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...)
568or hexadecimal (0xNNN...)
569.TP
570.BR "\-\-function (addr | symbol | symbol+offset)"
571Dynamic function entry/return probe. Addr and offset can be octal
572(0NNN...), decimal (NNN...) or hexadecimal (0xNNN...)
573.TP
574.BR "\-\-syscall"
575System call event. Enabling syscalls tracing (kernel tracer), you will
576not be able to disable them with disable-event. This is a known
627dbfd8
CB
577limitation. You can disable the entire channel to do the trick. Also note
578that per-syscall selection is not supported yet. Use with "-a" to enable
579all syscalls.
6a240cd9
MD
580.TP
581.BR "\-\-filter 'expression'"
582Set a filter on a newly enabled event. Filter expression on event
e256d661
JG
583fields and context. The event will be recorded if the filter's
584expression evaluates to TRUE. Only specify on first activation of a
585given event within a session.
586Specifying a filter is only allowed when enabling events within a session before
6a240cd9
MD
587tracing is started. If the filter fails to link with the event
588within the traced domain, the event will be discarded.
e256d661 589Filtering is currently only implemented for the user-space tracer.
6a240cd9
MD
590
591Expression examples:
592
593.nf
594 'intfield > 500 && intfield < 503'
595 '(strfield == "test" || intfield != 10) && intfield > 33'
596 'doublefield > 1.1 && intfield < 5.3'
597.fi
598
599Wildcards are allowed at the end of strings:
600 'seqfield1 == "te*"'
601In string literals, the escape character is a '\\'. Use '\\*' for
e256d661
JG
602the '*' character, and '\\\\' for the '\\' character sequence. Wildcard
603matches any sequence of characters, including an empty sub-string
604(matches 0 or more characters).
6a240cd9 605
e256d661
JG
606Context information can be used for filtering. The examples below shows
607usage of context filtering on the process name (using a wildcard), process ID
608range, and unique thread ID. The process and thread IDs of
6a240cd9
MD
609running applications can be found under columns "PID" and "LWP" of the
610"ps -eLf" command.
611
612.nf
613 '$ctx.procname == "demo*"'
614 '$ctx.vpid >= 4433 && $ctx.vpid < 4455'
615 '$ctx.vtid == 1234'
616.fi
617
11139b74
DG
618Context information is available to all filters whether or not the add-context
619command has been used to add it to the event's channel, as long as the context
620field exists for that domain. For example, the filter examples given above will
621never fail to link: no add-context is required for the event's channel.
622
bccd20a3
JI
623.TP
624.BR "\-x, \-\-exclude LIST"
625Add exclusions to UST tracepoints:
626Events that match any of the items in the comma-separated LIST are not
627enabled, even if they match a wildcard definition of the event.
628
629This option is also applicable with the \fB\-a, \-\-all\fP option,
630in which case all UST tracepoints are enabled except the ones whose
631names match any of the items in LIST.
6a240cd9
MD
632.RE
633.PP
6991b181 634
272c6a17
MD
635.PP
636\fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
637.RS
6991b181
DG
638Disable tracing channel
639
e256d661 640Disabling a channel disables the tracing of all of the channel's events. A channel
5368d366 641can be re-enabled by calling \fBlttng enable-channel NAME\fP again.
6991b181 642
c9e32613 643If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 644file.
6991b181
DG
645
646.B OPTIONS:
647
272c6a17
MD
648.TP
649.BR "\-h, \-\-help"
650Show summary of possible options and commands.
651.TP
652.BR "\-\-list-options"
653Simple listing of options
654.TP
655.BR "\-s, \-\-session NAME"
656Apply on session name
657.TP
658.BR "\-k, \-\-kernel"
659Apply for the kernel tracer
660.TP
661.BR "\-u, \-\-userspace"
662Apply for the user-space tracer
663.RE
664.PP
6991b181 665
c138a39b
MD
666.PP
667\fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
668.RS
6991b181
DG
669Disable tracing event
670
671The event, once disabled, can be re-enabled by calling \fBlttng enable-event
672NAME\fP again.
673
c9e32613 674If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 675file.
6991b181 676
85076754
MD
677If \fB\-c, \-\-channel\fP is omitted, the default channel name is used.
678If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already
679exists within the session, an error is returned.
680
6991b181
DG
681.B OPTIONS:
682
c138a39b
MD
683.TP
684.BR "\-h, \-\-help"
685Show summary of possible options and commands.
686.TP
687.BR "\-\-list-options"
688Simple listing of options
689.TP
690.BR "\-s, \-\-session NAME"
691Apply on session name
692.TP
85076754
MD
693.BR "\-c, \-\-channel NAME"
694Apply on channel name
695.TP
c138a39b
MD
696.BR "\-a, \-\-all-events"
697Disable all events. This does NOT disable "*" but rather every known
698events of the session.
699.TP
700.BR "\-k, \-\-kernel"
701Apply for the kernel tracer
702.TP
703.BR "\-u, \-\-userspace"
704Apply for the user-space tracer
bed69e7d
DG
705.TP
706.BR "\-j, \-\-jul"
707Apply for Java application using Java Util Logging interface (JUL)
222e4eab
DG
708.TP
709.BR "\-l, \-\-log4j"
710Apply for Java application using LOG4J
c138a39b
MD
711.RE
712.PP
6991b181 713
747361fe
MD
714.PP
715\fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]]
716.RS
c9e32613 717List tracing session information.
6991b181
DG
718
719With no arguments, it will list available tracing session(s).
720
fa072eae
YB
721With the session name, it will display the details of the session including
722the trace file path, the associated channels and their state (activated
d829b38c 723and deactivated), the activated events and more.
fa072eae 724
c9e32613 725With \-k alone, it will list all available kernel events (except the system
6991b181 726calls events).
bed69e7d
DG
727With \-j alone, the available JUL event from registered application will be
728list. The event corresponds to the Logger name in the Java JUL application.
999ee001
DG
729With \-l alone, the available LOG4J event from registered application will be
730list. The event corresponds to the Logger name in the Java LOG4J application.
c9e32613
DG
731With \-u alone, it will list all available user-space events from registered
732applications. Here is an example of 'lttng list \-u':
6991b181 733
747361fe 734.nf
6991b181
DG
735PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello
736 ust_tests_hello:tptest_sighandler (type: tracepoint)
737 ust_tests_hello:tptest (type: tracepoint)
747361fe 738.fi
6991b181
DG
739
740You can now enable any event listed by using the name :
741\fBust_tests_hello:tptest\fP.
6991b181
DG
742
743.B OPTIONS:
744
747361fe
MD
745.TP
746.BR "\-h, \-\-help"
747Show summary of possible options and commands.
748.TP
749.BR "\-\-list-options"
750Simple listing of options
751.TP
752.BR "\-k, \-\-kernel"
753Select kernel domain
754.TP
755.BR "\-u, \-\-userspace"
756Select user-space domain.
bed69e7d
DG
757.TP
758.BR "\-j, \-\-jul"
759Apply for Java application using JUL
760.TP
222e4eab
DG
761.TP
762.BR "\-l, \-\-log4j"
763Apply for Java application using LOG4J
bed69e7d
DG
764.BR "\-f, \-\-fields"
765List event fields
6991b181 766
747361fe 767.PP
6b8f2e64
DG
768.B SESSION OPTIONS:
769
747361fe
MD
770.TP
771.BR "\-c, \-\-channel NAME"
772List details of a channel
773.TP
774.BR "\-d, \-\-domain"
775List available domain(s)
776.RE
777.PP
6991b181 778
516f6cbe
JG
779.PP
780\fBload\fP [OPTIONS] [NAME]
781.RS
782Load tracing session configuration
783
784If NAME is omitted, all session configurations found in both the user's session
bd88d988 785configuration directory (default: ~/.lttng/sessions/) and the system session
cf53c06d
DG
786configuration directory (default: /etc/lttng/sessions/) will be loaded. Note
787that the sessions in the user directory are loaded first and then the system
788wide directory are loaded.
516f6cbe
JG
789
790.B OPTIONS:
791
792.TP
793.BR "\-h, \-\-help"
794Show summary of possible options and commands.
795.TP
796.BR "\-a, \-\-all"
797Load all session configurations (default).
798.TP
799.BR "\-i, \-\-input-path PATH"
bd88d988
DG
800Specify the input path for session configurations. This overrides the default
801session configuration directory.
516f6cbe
JG
802.TP
803.BR "\-f, -\-force"
804Overwrite current session configuration(s) if a session of the same name
805already exists.
806.RE
807.PP
808
809.PP
810\fBsave\fP [OPTIONS] [SESSION]
811.RS
812Save tracing session configuration
813
814If SESSION is omitted, all session configurations will be saved to individual
553067af 815\fB.lttng\fP files under the user's session configuration directory (default:
bd88d988
DG
816~/.lttng/sessions/). The default session configuration file naming scheme is
817\fBSESSION.lttng\fP.
516f6cbe 818
cf53c06d
DG
819For instance, a user in the tracing group saving a session from a root session
820daemon will save it in her/his user directory.
821
516f6cbe
JG
822.B OPTIONS:
823
824.TP
825.BR "\-h, \-\-help"
826Show summary of possible options and commands.
827.TP
828.BR "\-a, \-\-all"
829Save all session configurations (default).
830.TP
831.BR "\-o, \-\-output-path PATH"
553067af
DG
832Specify the output path for saved sessions. This overrides the default session
833configuration directory.
516f6cbe
JG
834.TP
835.BR "\-f, -\-force"
836Overwrite session configuration file if session name clashes.
837.RE
838.PP
839
7c96a096
MD
840.PP
841\fBset-session\fP NAME [OPTIONS]
842.RS
6991b181
DG
843Set current session name
844
845Will change the session name in the .lttngrc file.
6991b181
DG
846
847.B OPTIONS:
848
7c96a096
MD
849.TP
850.BR "\-h, \-\-help"
851Show summary of possible options and commands.
852.TP
853.BR "\-\-list-options"
854Simple listing of options
855.RE
856.PP
6991b181 857
8df3bfe9
MD
858.PP
859\fBsnapshot\fP [OPTIONS] ACTION
860.RS
b872baea 861Snapshot command for LTTng session.
b872baea
DG
862
863.B OPTIONS:
864
8df3bfe9
MD
865.TP
866.BR "\-h, \-\-help"
867Show summary of possible options and commands.
868.TP
869.BR "\-\-list-options"
870Simple listing of options
b872baea 871
8df3bfe9 872.PP
b872baea
DG
873.B ACTION:
874
8df3bfe9 875.TP
b872baea
DG
876\fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL>
877
878Setup and add an snapshot output for a session. Output are the destination
879where the snapshot will be sent. Only one output is permitted. To change it,
880you'll need to delete it and add back the new one.
881
8df3bfe9 882.TP
b872baea
DG
883\fBdel-output\fP ID | NAME [-s <NAME>]
884
885Delete an output for a session using the ID. You can either specify the
886output's ID that can be found with list-output or the name.
887
8df3bfe9 888.TP
b872baea
DG
889\fBlist-output\fP [-s <NAME>]
890
891List the output of a session. Attributes of the output are printed.
892
8df3bfe9 893.TP
b872baea
DG
894\fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>]
895
896Snapshot a session's buffer(s) for all domains. If an URL is specified, it is
897used instead of a previously added output. Specifying only a name or/and a max
898size will override the current output values. For instance, you can record a
899snapshot with a custom maximum size or with a different name.
900
8df3bfe9 901.nf
1ac1098f 902$ lttng snapshot add-output -n mysnapshot file:///data/snapshot
b872baea
DG
903[...]
904$ lttng snapshot record -n new_name_snapshot
8df3bfe9 905.fi
b872baea
DG
906
907The above will create a snapshot in /data/snapshot/new_name_snapshot* directory
908rather then in mysnapshot*/
b872baea 909
8df3bfe9
MD
910.PP
911.B DETAILED ACTION OPTIONS
b872baea 912
8df3bfe9
MD
913.TP
914.BR "\-s, \-\-session NAME"
915Apply to session name.
916.TP
917.BR "\-n, \-\-name NAME"
918Name of the snapshot's output.
919.TP
920.BR "\-m, \-\-max-size SIZE"
eb82f91d 921Maximum size in bytes of the snapshot. The maximum size does not include the
a8f307d8
SM
922metadata file. Human readable format is accepted: {+k,+M,+G}. For instance,
923\-\-max-size 5M
68808f4e
DG
924
925The minimum size of a snapshot is computed by multiplying the total amount of
926streams in the session by the largest subbuffer size. This is to ensure
927fairness between channels when extracting data.
8df3bfe9
MD
928.TP
929.BR "\-C, \-\-ctrl-url URL"
930Set control path URL. (Must use -D also)
931.TP
932.BR "\-D, \-\-data-url URL"
933Set data path URL. (Must use -C also)
934.RE
935.PP
b872baea 936
afb8ca1b
MD
937.PP
938\fBstart\fP [NAME] [OPTIONS]
939.RS
6991b181
DG
940Start tracing
941
942It will start tracing for all tracers for a specific tracing session.
6991b181 943If NAME is omitted, the session name is taken from the .lttngrc file.
6991b181
DG
944
945.B OPTIONS:
946
afb8ca1b
MD
947.TP
948.BR "\-h, \-\-help"
949Show summary of possible options and commands.
950.TP
951.BR "\-\-list-options"
952Simple listing of options
953.RE
954.PP
6991b181 955
6c09bfdb
MD
956.PP
957\fBstop\fP [NAME] [OPTIONS]
958.RS
6991b181
DG
959Stop tracing
960
391b9c72
DG
961It will stop tracing for all tracers for a specific tracing session. Before
962returning, the command checks for data availability meaning that it will wait
963until the trace is readable for the session. Use \-\-no-wait to avoid this
964behavior.
6991b181
DG
965
966If NAME is omitted, the session name is taken from the .lttngrc file.
6991b181
DG
967
968.B OPTIONS:
969
6c09bfdb
MD
970.TP
971.BR "\-h, \-\-help"
972Show summary of possible options and commands.
973.TP
974.BR "\-\-list-options"
975Simple listing of options
3a7a166e
MJ
976.TP
977.BR "\-\-no-wait"
6c09bfdb
MD
978Don't wait for data availability.
979.RE
980.PP
6991b181 981
5975c30a
MD
982.PP
983\fBversion\fP
984.RS
6991b181 985Show version information
6991b181
DG
986
987.B OPTIONS:
988
5975c30a
MD
989.TP
990.BR "\-h, \-\-help"
991Show summary of possible options and commands.
992.TP
993.BR "\-\-list-options"
994Simple listing of options
995.RE
996.PP
6991b181 997
5b4c1410
MD
998.PP
999\fBview\fP [SESSION_NAME] [OPTIONS]
1000.RS
1001View traces of a tracing session. By default, the babeltrace viewer
1002will be used for text viewing. If SESSION_NAME is omitted, the session
1003name is taken from the .lttngrc file.
6991b181
DG
1004
1005.B OPTIONS:
1006
5b4c1410
MD
1007.TP
1008.BR "\-h, \-\-help"
1009Show this help
1010.TP
1011.BR "\-\-list-options"
1012Simple listing of options
1013.TP
1014.BR "\-t, \-\-trace-path PATH"
1015Trace directory path for the viewer
1016.TP
1017.BR "\-e, \-\-viewer CMD"
1018Specify viewer and/or options to use This will completely override the
1019default viewers so please make sure to specify the full command. The
1020trace directory path of the session will be appended at the end to the
1021arguments
1022.RE
1023.PP
6991b181 1024
999ee001
DG
1025.SH "JUL/LOG4J DOMAIN"
1026
1027This section explains the JUL and LOG4J domain where JUL stands for Java Util
1028Logging. You can use these by using the \fBliblttng-ust-<domain>-jni.so\fP from
1029the lttng-ust(3) project.
acf47627
DG
1030
1031The LTTng Java Agent uses JNI to link the UST tracer to the Java application
1032that uses the agent. Thus, it behaves similarly to the UST domain (\-u). When
999ee001
DG
1033enabling events, you enable a Logger name that will then be mapped to a default
1034UST tracepoint called \fBlttng_jul:<domain>_event\fP in the
1035\fBlttng_<domain>_channel\fP. Using the lttng-ctl API, any JUL/LOG4J events
1036must use the tracepoint event type (same as \-\-tracepoint).
acf47627 1037
999ee001
DG
1038Because of the default immutable channel, the \fBenable-channel\fP command CAN
1039NOT be used with the JUL and LOG4J domain thus not having any options.
acf47627 1040
999ee001
DG
1041Also, loglevels are supported. Use \fBlttng enable-event \-h\fP to list them.
1042Wildcards are NOT supported except the "*" meaning all events (same as \-a).
acf47627
DG
1043
1044Exactly like the UST domain, if the Java application has the same UID as you,
1045you can trace it. Same goes for the tracing group accessing root applications.
1046
999ee001
DG
1047Finally, you can list every Logger name that are available from registered
1048applications to the session daemon by using \fBlttng list \-j\fP or \fB\-l\fP.
acf47627 1049
999ee001 1050Here is an example on how to use the JUL domain.
acf47627
DG
1051
1052.nf
1053$ lttng list -j
1054[...]
1055$ lttng create aSession
1056$ lttng enable-event -s aSession -j MyCustomLoggerName
1057$ lttng start
1058.fi
1059
1060More information can be found in the lttng-ust documentation, see
1061java-util-logging.txt
1062.PP
1063
c206d957 1064.SH "EXIT VALUES"
b107a0b1 1065.PP
6b8f2e64
DG
1066On success 0 is returned and a positive value on error. Value of 1 means a command
1067error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that
1068something went wrong during the command.
c206d957 1069
6b8f2e64 1070Any other value above 10, please refer to
b107a0b1 1071.BR "<lttng/lttng-error.h>"
6b8f2e64
DG
1072for a detailed list or use lttng_strerror() to get a human readable string of
1073the error code.
c206d957 1074.PP
b107a0b1 1075
6991b181
DG
1076.SH "ENVIRONMENT VARIABLES"
1077
1078.PP
1079Note that all command line options override environment variables.
1080.PP
1081
1082.PP
05833633 1083.IP "LTTNG_SESSIOND_PATH"
c9e32613
DG
1084Allows one to specify the full session daemon binary path to lttng command line
1085tool. You can also use \-\-sessiond-path option having the same effect.
b107a0b1
MD
1086.PP
1087
516f6cbe
JG
1088.PP
1089.IP "LTTNG_SESSION_CONFIG_XSD_PATH"
1090Set the path in which the \fBsession.xsd\fP session configuration schema may be
1091found.
1092.PP
1093
6991b181 1094.SH "SEE ALSO"
6b8f2e64
DG
1095.BR babeltrace(1),
1096.BR lttng-ust(3),
1097.BR lttng-sessiond(8),
1098.BR lttng-relayd(8),
b107a0b1 1099
6991b181
DG
1100.SH "BUGS"
1101
b107a0b1 1102.PP
6991b181 1103If you encounter any issues or usability problem, please report it on our
6b8f2e64 1104mailing list <lttng-dev@lists.lttng.org> to help improve this project or
eb82f91d 1105at https://bugs.lttng.org which is a bug tracker.
b107a0b1
MD
1106.PP
1107
6991b181
DG
1108.SH "CREDITS"
1109
1110.PP
c9e32613 1111lttng is distributed under the GNU General Public License version 2. See the file
6991b181
DG
1112COPYING for details.
1113.PP
1114A Web site is available at http://lttng.org for more information on the LTTng
1115project.
1116.PP
1117You can also find our git tree at http://git.lttng.org.
1118.PP
1119Mailing lists for support and development: <lttng-dev@lists.lttng.org>.
1120.PP
1121You can find us on IRC server irc.oftc.net (OFTC) in #lttng.
1122.PP
1123.SH "THANKS"
1124
1125.PP
1126Thanks to Yannick Brosseau without whom this project would never have been so
1127lean and mean! Also thanks to the Ericsson teams working on tracing which
fa072eae 1128helped us greatly with detailed bug reports and unusual test cases.
6991b181
DG
1129
1130Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA
1131maintainer) and Jon Bernard for our Debian packages.
1132
1133Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de
1134Montreal for the LTTng journey.
c9e32613 1135.PP
6991b181
DG
1136.SH "AUTHORS"
1137
1138.PP
1139lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and
1140David Goulet. More people have since contributed to it. It is currently
1141maintained by David Goulet <dgoulet@efficios.com>.
1142.PP
This page took 0.086919 seconds and 4 git commands to generate.