Man page fixes: missing --version option and typo
[lttng-tools.git] / doc / man / lttng.1
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516f6cbe 1.TH "LTTNG" "1" "May 13th, 2014" "" ""
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2
3.SH "NAME"
c5db699c 4lttng \(em LTTng 2.x tracer control command line tool
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5
6.SH "SYNOPSIS"
7
8.PP
6991b181 9lttng [OPTIONS] <COMMAND>
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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
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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
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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
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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)
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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
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30tracer (kernel, user space, JUL, LOG4J or Python for now). In the future, we
31could see more tracer like for instance an hypervisor. For some commands,
32you'll need to specify on which domain the command operates (\-u, \-k, \-l, \-j
33or \-p). For instance, the kernel domain must be specified when enabling a
34kernel event.
50a3b92a 35
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36In order to trace the kernel, the session daemon needs to be running as root.
37LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is
38in that group can interact with the root session daemon and thus trace the
e256d661 39kernel. Session daemons can co-exist, meaning that you can have a session daemon
fa072eae 40running as Alice that can be used to trace her applications along side with a
e256d661 41root daemon or even a Bob daemon. We highly recommend starting the session
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42daemon at boot time for stable and long term tracing.
43
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44Each user-space application instrumented with lttng-ust(3) will automatically
45register with the root session daemon and its user session daemon. This allows
46each daemon to list the available traceable applications and tracepoints at any
47given moment (See the \fBlist\fP command).
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48.SH "OPTIONS"
49
50.PP
c0fdca17 51This program follows the usual GNU command line syntax with long options starting with
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52two dashes. Below is a summary of the available options.
53.PP
54
55.TP
c9e32613 56.BR "\-h, \-\-help"
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57Show summary of possible options and commands.
58.TP
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59.BR "\-V, \-\-version"
60Show version.
61.TP
c9e32613 62.BR "\-v, \-\-verbose"
6991b181 63Increase verbosity.
d829b38c 64Three levels of verbosity are available which are triggered by putting additional v to
fa072eae 65the option (\-vv or \-vvv)
6991b181 66.TP
c9e32613 67.BR "\-q, \-\-quiet"
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68Suppress all messages (even errors).
69.TP
c9e32613 70.BR "\-g, \-\-group NAME"
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71Set unix tracing group name. (default: tracing)
72.TP
c9e32613 73.BR "\-n, \-\-no-sessiond"
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74Don't automatically spawn a session daemon.
75.TP
391b9c72 76.BR "\-\-sessiond\-path PATH"
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77Set session daemon full binary path.
78.TP
c9e32613 79.BR "\-\-list\-options"
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80Simple listing of lttng options.
81.TP
c9e32613 82.BR "\-\-list\-commands"
6991b181 83Simple listing of lttng commands.
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84.TP
85.BR "\-m, \-\-mi TYPE
86Machine interface
87
88TYPE supported: XML
89
90Machine interface (MI) mode converts the traditional pretty printing to a
91machine output syntax. MI mode provides a format change-resistant way to access
92information generated via the lttng command line.
93
94When using MI mode, the data is printed on \fBstdout\fP. Error and warning are
95printed on \fBstderr\fP with the pretty print default format.
96
97If any errors occur during the execution of a command, the return value of the
98command will be different than zero. In this case, lttng does NOT guarantee the
99syntax and data validity of the generated MI output.
100
101For XML output type, a schema definition (XSD) file used for validation can be
102found under src/common/mi_lttng.xsd
103
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104.SH "COMMANDS"
105
812a5eb7 106.PP
ee2758e5 107\fBadd-context\fP [OPTIONS]
812a5eb7 108.RS
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109Add context to event(s) and/or channel(s).
110
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111A context is basically extra information appended to a channel. For instance,
112you could ask the tracer to add the PID information for all events in a
113channel. You can also add performance monitoring unit counters (perf PMU) using
aa3514e9 114the perf kernel API.
6991b181 115
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116For example, this command will add the context information 'prio' and two per-CPU
117perf counters (hardware branch misses and cache misses), to all events in the trace
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118data output:
119
812a5eb7 120.nf
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121# lttng add-context \-k \-t prio \-t perf:cpu:branch-misses \\
122 \-t perf:cpu:cache-misses
812a5eb7 123.fi
6991b181 124
c9e32613 125Please take a look at the help (\-h/\-\-help) for a detailed list of available
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126contexts.
127
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128Perf counters are available as per-CPU ("perf:cpu:...") and per-thread
129("perf:thread:...") counters. Currently, per-CPU counters can only be
130used with the kernel tracing domain, and per-thread counters can only be
131used with the UST tracing domain.
132
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133If no channel is given (\-c), the context is added to all channels that were
134already enabled. If the session has no channel, a default channel is created.
31ea4846 135Otherwise the context will be added only to the given channel (\-c).
6991b181 136
c9e32613 137If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 138file.
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139
140.B OPTIONS:
141
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142.TP
143.BR "\-h, \-\-help"
144Show summary of possible options and commands.
145.TP
146.BR "\-s, \-\-session NAME"
147Apply on session name.
148.TP
149.BR "\-c, \-\-channel NAME"
150Apply on channel name.
151.TP
152.BR "\-k, \-\-kernel"
153Apply for the kernel tracer
154.TP
155.BR "\-u, \-\-userspace"
156Apply for the user-space tracer
157.TP
158.BR "\-t, \-\-type TYPE"
159Context type. You can repeat this option on the command line. Please
160use "lttng add-context \-h" to list all available types.
161.RE
162.PP
6991b181 163
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164.PP
165\fBcalibrate\fP [OPTIONS]
166.RS
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167Quantify LTTng overhead
168
169The LTTng calibrate command can be used to find out the combined average
170overhead of the LTTng tracer and the instrumentation mechanisms used. This
171overhead can be calibrated in terms of time or using any of the PMU performance
172counter available on the system.
173
174For now, the only calibration implemented is that of the kernel function
175instrumentation (kretprobes).
176
177* Calibrate kernel function instrumentation
178
179Let's use an example to show this calibration. We use an i7 processor with 4
180general-purpose PMU registers. This information is available by issuing dmesg,
181looking for "generic registers".
182
183This sequence of commands will gather a trace executing a kretprobe hooked on
184an empty function, gathering PMU counters LLC (Last Level Cache) misses
c9e32613 185information (see lttng add-context \-\-help to see the list of available PMU
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186counters).
187
22019883 188.nf
6991b181 189# lttng create calibrate-function
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190# lttng enable-event calibrate \-\-kernel \\
191 \-\-function lttng_calibrate_kretprobe
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192# lttng add-context \-\-kernel \-t perf:cpu:LLC-load-misses \\
193 \-t perf:cpu:LLC-store-misses \\
194 \-t perf:cpu:LLC-prefetch-misses
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195# lttng start
196# for a in $(seq 1 10); do \\
c9e32613 197 lttng calibrate \-\-kernel \-\-function;
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198 done
199# lttng destroy
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200# babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\
201 | tail \-n 1)
202.fi
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203
204The output from babeltrace can be saved to a text file and opened in a
205spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between
206consecutive "calibrate_entry" and "calibrate_return" events. Note that these
207counters are per-CPU, so scheduling events would need to be present to account
208for migration between CPU. Therefore, for calibration purposes, only events
209staying on the same CPU must be considered.
210
211The average result, for the i7, on 10 samples:
212
22019883 213.nf
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214 Average Std.Dev.
215perf_LLC_load_misses: 5.0 0.577
216perf_LLC_store_misses: 1.6 0.516
217perf_LLC_prefetch_misses: 9.0 14.742
22019883 218.fi
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219
220As we can notice, the load and store misses are relatively stable across runs
221(their standard deviation is relatively low) compared to the prefetch misses.
222We can conclude from this information that LLC load and store misses can be
223accounted for quite precisely, but prefetches within a function seems to behave
224too erratically (not much causality link between the code executed and the CPU
225prefetch activity) to be accounted for.
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226
227.B OPTIONS:
228
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229.TP
230.BR "\-h, \-\-help"
231Show summary of possible options and commands.
232.TP
233.BR "\-k, \-\-kernel"
234Apply for the kernel tracer
235.TP
236.BR "\-u, \-\-userspace"
237Apply for the user-space tracer
238.TP
239.BR "\-\-function"
240Dynamic function entry/return probe (default)
241.RE
242.PP
6991b181 243
ee2758e5 244.PP
feb3ca56 245\fBcreate\fP [NAME] [OPTIONS]
ee2758e5 246.RS
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247Create tracing session.
248
249A tracing session contains channel(s) which contains event(s). It is domain
e256d661 250agnostic, meaning that channels and events can be enabled for the
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251user-space tracer and/or the kernel tracer. It acts like a container
252aggregating multiple tracing sources.
253
254On creation, a \fB.lttngrc\fP file is created in your $HOME directory
255containing the current session name. If NAME is omitted, a session name is
fa072eae 256automatically created having this form: 'auto-yyyymmdd-hhmmss'.
6991b181 257
c9e32613 258If no \fB\-o, \-\-output\fP is specified, the traces will be written in
6991b181 259$HOME/lttng-traces.
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260
261The $HOME environment variable can be overridden by defining the environment
262variable LTTNG_HOME. This is useful when the user running the commands has
263a non-writeable home directory.
6991b181 264
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265The session name MUST NOT contain the character '/'.
266
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267.B OPTIONS:
268
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269.TP
270.BR "\-h, \-\-help"
271Show summary of possible options and commands.
272.TP
273.BR "\-\-list-options"
274Simple listing of options
275.TP
276.BR "\-o, \-\-output PATH"
277Specify output path for traces
278.TP
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279.BR "\-\-no-output"
280Traces will not be output
281.TP
ee2758e5 282.BR "\-\-snapshot"
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283Set the session in snapshot mode. Created in no-output mode and uses the
284URL, if one is specified, as the default snapshot output. Every channel will be set
ee2758e5 285in overwrite mode and with mmap output (splice not supported).
0794f51b 286.TP
d73c5802 287.BR "\-\-live [USEC]"
eb82f91d 288Set the session exclusively in live mode. The parameter is the delay in micro
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289seconds before the data is flushed and streamed. The live mode allows you to
290stream the trace and view it while it's being recorded by any tracer. For that,
291you need a lttng-relayd and this session requires a network URL (\-U or
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292\-C/\-D). If no USEC nor URL is provided, the default is to use a timer value
293set to 1000000 and the network URL set to net://127.0.0.1.
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294
295To read a live session, you can use babeltrace(1) or the live streaming
296protocol in doc/live-reading-protocol.txt. Here is an example:
297
298.nf
299$ lttng-relayd -o /tmp/lttng
300$ lttng create --live 200000 -U net://localhost
301$ lttng enable-event -a --userspace
302$ lttng start
303.fi
304
305After the start, you'll be able to read the events while they are being
306recorded in /tmp/lttng.
6b8f2e64 307
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308.TP
309.BR "\-\-shm-path PATH"
310
311Path where shared memory holding buffers should be created. Useful
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312when used with PRAMFS or other persistent memory filesystems to extract
313trace data in the event of a crash requiring a reboot.
d7ba1388 314
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315.TP
316.BR "\-U, \-\-set-url=URL"
317Set URL for the consumer output destination. It is persistent for the
318session lifetime. Redo the command to change it. This will set both data
319and control URL for network.
320.TP
321.BR "\-C, \-\-ctrl-url=URL"
322Set control path URL. (Must use -D also)
323.TP
324.BR "\-D, \-\-data-url=URL"
325Set data path URL. (Must use -C also)
326.PP
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327Using these options, each API call can be controlled individually. For
328instance, \-C does not enable the consumer automatically. You'll need the \-e
329option for that.
330
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331.B URL FORMAT:
332
333proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
334
335Supported protocols are (proto):
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336.TP
337.BR "file://..."
338Local filesystem full path.
785d2d0d 339
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340.TP
341.BR "net://..."
342This will use the default network transport layer which is TCP for both
343control (PORT1) and data port (PORT2). The default ports are
344respectively 5342 and 5343. Note that net[6]:// is not yet supported.
785d2d0d 345
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346.TP
347.BR "tcp[6]://..."
348Can only be used with -C and -D together
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349
350NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732)
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351
352.B EXAMPLES:
353
ee2758e5 354.nf
6b8f2e64 355# lttng create -U net://192.168.1.42
ee2758e5 356.fi
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357Uses TCP and default ports for the given destination.
358
ee2758e5 359.nf
6b8f2e64 360# lttng create -U net6://[fe80::f66d:4ff:fe53:d220]
ee2758e5 361.fi
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362Uses TCP, default ports and IPv6.
363
ee2758e5 364.nf
6b8f2e64 365# lttng create s1 -U net://myhost.com:3229
6991b181 366.fi
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367Create session s1 and set its consumer to myhost.com on port 3229 for control.
368.RE
369.PP
6991b181 370
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371.PP
372\fBdestroy\fP [NAME] [OPTIONS]
373.RS
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374Teardown tracing session
375
376Free memory on the session daemon and tracer side. It's gone!
377
378If NAME is omitted, the session name is taken from the .lttngrc file.
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379
380.B OPTIONS:
381
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382.TP
383.BR "\-h, \-\-help"
384Show summary of possible options and commands.
385.TP
386.BR "\-a, \-\-all"
387Destroy all sessions
388.TP
389.BR "\-\-list-options"
390Simple listing of options
391.RE
392.PP
6991b181 393
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394.PP
395\fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
396.RS
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397Enable tracing channel
398
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399To enable an event, you must enable both the event and the channel that
400contains it.
b883c01b 401
c9e32613 402If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 403file.
7972aab2 404
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405Exactly one of \-k or -u must be specified.
406
7972aab2 407It is important to note that if a certain type of buffers is used, the session
bd337b98 408will be set with that type and all other subsequent channel needs to have the
7972aab2 409same type.
bd337b98 410
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411Note that once the session has been started and enabled on the tracer side,
412it's not possible anymore to enable a new channel for that session.
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413
414.B OPTIONS:
415
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416.TP
417.BR "\-h, \-\-help"
418Show this help
419.TP
420.BR "\-\-list-options"
421Simple listing of options
422.TP
423.BR "\-s, \-\-session NAME"
424Apply on session name
425.TP
426.BR "\-k, \-\-kernel"
427Apply to the kernel tracer
428.TP
429.BR "\-u, \-\-userspace"
430Apply to the user-space tracer
431.TP
432.BR "\-\-discard"
433Discard event when subbuffers are full (default)
434.TP
435.BR "\-\-overwrite"
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436Flight recorder mode: overwrites events when subbuffers are full. The
437number of subbuffer must be 2 or more.
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438.TP
439.BR "\-\-subbuf-size SIZE"
440Subbuffer size in bytes {+k,+M,+G}.
441(default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096)
442Rounded up to the next power of 2.
443
444The minimum subbuffer size, for each tracer, is the max value between
445the default above and the system page size. You can issue this command
446to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP
447.TP
448.BR "\-\-num-subbuf NUM"
449Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4,
450metadata: 2) Rounded up to the next power of 2.
451.TP
452.BR "\-\-switch-timer USEC"
453Switch subbuffer timer interval in µsec.
454(default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0)
455.TP
456.BR "\-\-read-timer USEC"
457Read timer interval in µsec.
458(default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0)
459.TP
460.BR "\-\-output TYPE"
461Channel output type. Possible values: mmap, splice
462(default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap)
463.TP
464.BR "\-\-buffers-uid"
465Use per UID buffer (\-u only). Buffers are shared between applications
466that have the same UID.
467.TP
468.BR "\-\-buffers-pid"
469Use per PID buffer (\-u only). Each application has its own buffers.
470.TP
471.BR "\-\-buffers-global"
472Use shared buffer for the whole system (\-k only)
473.TP
474.BR "\-C, \-\-tracefile-size SIZE"
475Maximum size of each tracefile within a stream (in bytes).
4760 means unlimited. (default: 0)
c0684a0d 477Note: traces generated with this option may inaccurately report
a10f04ad 478discarded events as of CTF 1.8.
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479.TP
480.BR "\-W, \-\-tracefile-count COUNT"
481Used in conjunction with \-C option, this will limit the number of files
482created to the specified count. 0 means unlimited. (default: 0)
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483
484.B EXAMPLES:
485
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486.nf
487$ lttng enable-channel -k -C 4096 -W 32 chan1
488.fi
e256d661 489For each stream, the maximum size of each trace file will be 4096 bytes and
cea28771 490there will be a maximum of 32 different files. The file count is appended after
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491the stream number as seen in the following example. The last trace file is
492smaller than 4096 since it was not completely filled.
493
05be3802 494.nf
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495 ~/lttng-traces/[...]/chan1_0_0 (4096)
496 ~/lttng-traces/[...]/chan1_0_1 (4096)
497 ~/lttng-traces/[...]/chan1_0_2 (3245)
498 ~/lttng-traces/[...]/chan1_1_0 (4096)
499 ...
05be3802 500.fi
1624d5b7 501
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502.nf
503$ lttng enable-channel -k -C 4096
504.fi
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505This will create trace files of 4096 bytes and will create new ones as long as
506there is data available.
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507.RE
508.PP
6991b181 509
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510.PP
511\fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]
512.RS
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513Enable tracing event
514
c9e32613 515A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is
6991b181 516omitted, a default channel named '\fBchannel0\fP' is created and the event is
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517added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default
518channel already exists within the session, an error is returned. For the
519user-space tracer, using \fB\-a, \-\-all\fP is the same as using the
520wildcard "*".
6991b181 521
c9e32613 522If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 523file.
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524
525.B OPTIONS:
526
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527.TP
528.BR "\-h, \-\-help"
529Show summary of possible options and commands.
530.TP
531.BR "\-\-list-options"
532Simple listing of options
533.TP
534.BR "\-s, \-\-session NAME"
535Apply on session name
536.TP
537.BR "\-c, \-\-channel NAME"
538Apply on channel name
539.TP
540.BR "\-a, \-\-all"
e256d661 541Enable all tracepoints and syscalls. This actually enables a single
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542wildcard event "*".
543.TP
544.BR "\-k, \-\-kernel"
545Apply for the kernel tracer
546.TP
547.BR "\-u, \-\-userspace"
548Apply for the user-space tracer
549.TP
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550.BR "\-j, \-\-jul"
551Apply for Java application using Java Util Logging interface (JUL)
552.TP
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553.BR "\-l, \-\-log4j"
554Apply for Java application using LOG4J
555.TP
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556.BR "\-p, \-\-python"
557Apply for Python application using the logging module.
558.TP
6a240cd9 559.BR "\-\-tracepoint"
e256d661 560Tracepoint event (default). Userspace tracer supports wildcards at the end
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561of string. Don't forget to quote to deal with bash expansion.
562e.g.:
6991b181 563.nf
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564 "*"
565 "app_component:na*"
6991b181 566.fi
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567.TP
568.BR "\-\-loglevel NAME"
569Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h).
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570For the JUL domain, the loglevel ranges are detailed with the \-\-help
571option thus starting from SEVERE to FINEST.
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572For the LOG4J domain, loglevels range from FATAL to TRACE which are also
573detailed in the help.
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574For the Python domain, loglevels range from CRITICAL to DEBUG which are
575detailed in the help as well.
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576.TP
577.BR "\-\-loglevel-only NAME"
578Tracepoint loglevel (only this loglevel).
579The loglevel or loglevel-only options should be combined with a
580tracepoint name or tracepoint wildcard.
581.TP
582.BR "\-\-probe (addr | symbol | symbol+offset)"
583Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...)
584or hexadecimal (0xNNN...)
585.TP
586.BR "\-\-function (addr | symbol | symbol+offset)"
587Dynamic function entry/return probe. Addr and offset can be octal
588(0NNN...), decimal (NNN...) or hexadecimal (0xNNN...)
589.TP
590.BR "\-\-syscall"
591System call event. Enabling syscalls tracing (kernel tracer), you will
592not be able to disable them with disable-event. This is a known
627dbfd8
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593limitation. You can disable the entire channel to do the trick. Also note
594that per-syscall selection is not supported yet. Use with "-a" to enable
595all syscalls.
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596.TP
597.BR "\-\-filter 'expression'"
598Set a filter on a newly enabled event. Filter expression on event
e256d661
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599fields and context. The event will be recorded if the filter's
600expression evaluates to TRUE. Only specify on first activation of a
601given event within a session.
602Specifying a filter is only allowed when enabling events within a session before
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603tracing is started. If the filter fails to link with the event
604within the traced domain, the event will be discarded.
e256d661 605Filtering is currently only implemented for the user-space tracer.
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606
607Expression examples:
608
609.nf
610 'intfield > 500 && intfield < 503'
611 '(strfield == "test" || intfield != 10) && intfield > 33'
612 'doublefield > 1.1 && intfield < 5.3'
613.fi
614
615Wildcards are allowed at the end of strings:
616 'seqfield1 == "te*"'
617In string literals, the escape character is a '\\'. Use '\\*' for
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618the '*' character, and '\\\\' for the '\\' character sequence. Wildcard
619matches any sequence of characters, including an empty sub-string
620(matches 0 or more characters).
6a240cd9 621
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622Context information can be used for filtering. The examples below shows
623usage of context filtering on the process name (using a wildcard), process ID
624range, and unique thread ID. The process and thread IDs of
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625running applications can be found under columns "PID" and "LWP" of the
626"ps -eLf" command.
627
628.nf
629 '$ctx.procname == "demo*"'
630 '$ctx.vpid >= 4433 && $ctx.vpid < 4455'
631 '$ctx.vtid == 1234'
632.fi
633
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634Context information is available to all filters whether or not the add-context
635command has been used to add it to the event's channel, as long as the context
636field exists for that domain. For example, the filter examples given above will
637never fail to link: no add-context is required for the event's channel.
638
bccd20a3
JI
639.TP
640.BR "\-x, \-\-exclude LIST"
641Add exclusions to UST tracepoints:
642Events that match any of the items in the comma-separated LIST are not
643enabled, even if they match a wildcard definition of the event.
644
645This option is also applicable with the \fB\-a, \-\-all\fP option,
646in which case all UST tracepoints are enabled except the ones whose
647names match any of the items in LIST.
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648.RE
649.PP
6991b181 650
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651.PP
652\fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
653.RS
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654Disable tracing channel
655
e256d661 656Disabling a channel disables the tracing of all of the channel's events. A channel
5368d366 657can be re-enabled by calling \fBlttng enable-channel NAME\fP again.
6991b181 658
c9e32613 659If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 660file.
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661
662.B OPTIONS:
663
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664.TP
665.BR "\-h, \-\-help"
666Show summary of possible options and commands.
667.TP
668.BR "\-\-list-options"
669Simple listing of options
670.TP
671.BR "\-s, \-\-session NAME"
672Apply on session name
673.TP
674.BR "\-k, \-\-kernel"
675Apply for the kernel tracer
676.TP
677.BR "\-u, \-\-userspace"
678Apply for the user-space tracer
679.RE
680.PP
6991b181 681
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682.PP
683\fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
684.RS
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685Disable tracing event
686
687The event, once disabled, can be re-enabled by calling \fBlttng enable-event
688NAME\fP again.
689
c9e32613 690If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
6991b181 691file.
6991b181 692
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693If \fB\-c, \-\-channel\fP is omitted, the default channel name is used.
694If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already
695exists within the session, an error is returned.
696
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697.B OPTIONS:
698
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699.TP
700.BR "\-h, \-\-help"
701Show summary of possible options and commands.
702.TP
703.BR "\-\-list-options"
704Simple listing of options
705.TP
706.BR "\-s, \-\-session NAME"
707Apply on session name
708.TP
85076754
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709.BR "\-c, \-\-channel NAME"
710Apply on channel name
711.TP
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712.BR "\-a, \-\-all-events"
713Disable all events. This does NOT disable "*" but rather every known
714events of the session.
715.TP
716.BR "\-k, \-\-kernel"
717Apply for the kernel tracer
718.TP
719.BR "\-u, \-\-userspace"
720Apply for the user-space tracer
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721.TP
722.BR "\-j, \-\-jul"
723Apply for Java application using Java Util Logging interface (JUL)
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724.TP
725.BR "\-l, \-\-log4j"
726Apply for Java application using LOG4J
0e115563
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727.TP
728.BR "\-p, \-\-python"
729Apply for Python application using the logging module.
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730.RE
731.PP
6991b181 732
747361fe
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733.PP
734\fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]]
735.RS
c9e32613 736List tracing session information.
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737
738With no arguments, it will list available tracing session(s).
739
fa072eae
YB
740With the session name, it will display the details of the session including
741the trace file path, the associated channels and their state (activated
d829b38c 742and deactivated), the activated events and more.
fa072eae 743
c9e32613 744With \-k alone, it will list all available kernel events (except the system
6991b181 745calls events).
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746With \-j alone, the available JUL event from registered application will be
747list. The event corresponds to the Logger name in the Java JUL application.
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748With \-l alone, the available LOG4J event from registered application will be
749list. The event corresponds to the Logger name in the Java LOG4J application.
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750With \-p alone, the available Python event from registered application will be
751list. The event corresponds to the Logger name in the Python application.
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752With \-u alone, it will list all available user-space events from registered
753applications. Here is an example of 'lttng list \-u':
6991b181 754
747361fe 755.nf
6991b181
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756PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello
757 ust_tests_hello:tptest_sighandler (type: tracepoint)
758 ust_tests_hello:tptest (type: tracepoint)
747361fe 759.fi
6991b181
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760
761You can now enable any event listed by using the name :
762\fBust_tests_hello:tptest\fP.
6991b181
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763
764.B OPTIONS:
765
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766.TP
767.BR "\-h, \-\-help"
768Show summary of possible options and commands.
769.TP
770.BR "\-\-list-options"
771Simple listing of options
772.TP
773.BR "\-k, \-\-kernel"
774Select kernel domain
775.TP
776.BR "\-u, \-\-userspace"
777Select user-space domain.
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778.TP
779.BR "\-j, \-\-jul"
780Apply for Java application using JUL
781.TP
222e4eab
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782.BR "\-l, \-\-log4j"
783Apply for Java application using LOG4J
0e115563
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784.TP
785.BR "\-p, \-\-python"
786Apply for Python application using the logging module.
787.TP
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DG
788.BR "\-f, \-\-fields"
789List event fields
6991b181 790
747361fe 791.PP
6b8f2e64
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792.B SESSION OPTIONS:
793
747361fe
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794.TP
795.BR "\-c, \-\-channel NAME"
796List details of a channel
797.TP
798.BR "\-d, \-\-domain"
799List available domain(s)
800.RE
801.PP
6991b181 802
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803.PP
804\fBload\fP [OPTIONS] [NAME]
805.RS
806Load tracing session configuration
807
808If NAME is omitted, all session configurations found in both the user's session
bd88d988 809configuration directory (default: ~/.lttng/sessions/) and the system session
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810configuration directory (default: /etc/lttng/sessions/) will be loaded. Note
811that the sessions in the user directory are loaded first and then the system
812wide directory are loaded.
516f6cbe
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813
814.B OPTIONS:
815
816.TP
817.BR "\-h, \-\-help"
818Show summary of possible options and commands.
819.TP
820.BR "\-a, \-\-all"
821Load all session configurations (default).
822.TP
823.BR "\-i, \-\-input-path PATH"
bd88d988
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824Specify the input path for session configurations. This overrides the default
825session configuration directory.
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826.TP
827.BR "\-f, -\-force"
828Overwrite current session configuration(s) if a session of the same name
829already exists.
830.RE
831.PP
832
833.PP
834\fBsave\fP [OPTIONS] [SESSION]
835.RS
836Save tracing session configuration
837
838If SESSION is omitted, all session configurations will be saved to individual
553067af 839\fB.lttng\fP files under the user's session configuration directory (default:
bd88d988
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840~/.lttng/sessions/). The default session configuration file naming scheme is
841\fBSESSION.lttng\fP.
516f6cbe 842
cf53c06d
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843For instance, a user in the tracing group saving a session from a root session
844daemon will save it in her/his user directory.
845
516f6cbe
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846.B OPTIONS:
847
848.TP
849.BR "\-h, \-\-help"
850Show summary of possible options and commands.
851.TP
852.BR "\-a, \-\-all"
853Save all session configurations (default).
854.TP
855.BR "\-o, \-\-output-path PATH"
553067af
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856Specify the output path for saved sessions. This overrides the default session
857configuration directory.
516f6cbe
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858.TP
859.BR "\-f, -\-force"
860Overwrite session configuration file if session name clashes.
861.RE
862.PP
863
7c96a096
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864.PP
865\fBset-session\fP NAME [OPTIONS]
866.RS
6991b181
DG
867Set current session name
868
869Will change the session name in the .lttngrc file.
6991b181
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870
871.B OPTIONS:
872
7c96a096
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873.TP
874.BR "\-h, \-\-help"
875Show summary of possible options and commands.
876.TP
877.BR "\-\-list-options"
878Simple listing of options
879.RE
880.PP
6991b181 881
8df3bfe9
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882.PP
883\fBsnapshot\fP [OPTIONS] ACTION
884.RS
b872baea 885Snapshot command for LTTng session.
b872baea
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886
887.B OPTIONS:
888
8df3bfe9
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889.TP
890.BR "\-h, \-\-help"
891Show summary of possible options and commands.
892.TP
893.BR "\-\-list-options"
894Simple listing of options
b872baea 895
8df3bfe9 896.PP
b872baea
DG
897.B ACTION:
898
8df3bfe9 899.TP
b872baea
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900\fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL>
901
88743287 902Setup and add a snapshot output for a session. Output is the destination
b872baea
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903where the snapshot will be sent. Only one output is permitted. To change it,
904you'll need to delete it and add back the new one.
905
8df3bfe9 906.TP
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907\fBdel-output\fP ID | NAME [-s <NAME>]
908
88743287
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909Delete an output for a session using the output's ID. You can either specify the
910output by name or use its ID as returned by the list-output command.
b872baea 911
8df3bfe9 912.TP
b872baea
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913\fBlist-output\fP [-s <NAME>]
914
915List the output of a session. Attributes of the output are printed.
916
8df3bfe9 917.TP
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918\fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>]
919
920Snapshot a session's buffer(s) for all domains. If an URL is specified, it is
921used instead of a previously added output. Specifying only a name or/and a max
922size will override the current output values. For instance, you can record a
923snapshot with a custom maximum size or with a different name.
924
8df3bfe9 925.nf
1ac1098f 926$ lttng snapshot add-output -n mysnapshot file:///data/snapshot
b872baea
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927[...]
928$ lttng snapshot record -n new_name_snapshot
8df3bfe9 929.fi
b872baea
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930
931The above will create a snapshot in /data/snapshot/new_name_snapshot* directory
932rather then in mysnapshot*/
b872baea 933
8df3bfe9
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934.PP
935.B DETAILED ACTION OPTIONS
b872baea 936
8df3bfe9
MD
937.TP
938.BR "\-s, \-\-session NAME"
939Apply to session name.
940.TP
941.BR "\-n, \-\-name NAME"
942Name of the snapshot's output.
943.TP
944.BR "\-m, \-\-max-size SIZE"
eb82f91d 945Maximum size in bytes of the snapshot. The maximum size does not include the
a8f307d8
SM
946metadata file. Human readable format is accepted: {+k,+M,+G}. For instance,
947\-\-max-size 5M
8df3bfe9
MD
948.TP
949.BR "\-C, \-\-ctrl-url URL"
950Set control path URL. (Must use -D also)
951.TP
952.BR "\-D, \-\-data-url URL"
953Set data path URL. (Must use -C also)
954.RE
955.PP
b872baea 956
afb8ca1b
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957.PP
958\fBstart\fP [NAME] [OPTIONS]
959.RS
6991b181
DG
960Start tracing
961
962It will start tracing for all tracers for a specific tracing session.
6991b181 963If NAME is omitted, the session name is taken from the .lttngrc file.
6991b181
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964
965.B OPTIONS:
966
afb8ca1b
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967.TP
968.BR "\-h, \-\-help"
969Show summary of possible options and commands.
970.TP
971.BR "\-\-list-options"
972Simple listing of options
973.RE
974.PP
6991b181 975
6c09bfdb
MD
976.PP
977\fBstop\fP [NAME] [OPTIONS]
978.RS
6991b181
DG
979Stop tracing
980
391b9c72
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981It will stop tracing for all tracers for a specific tracing session. Before
982returning, the command checks for data availability meaning that it will wait
983until the trace is readable for the session. Use \-\-no-wait to avoid this
984behavior.
6991b181
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985
986If NAME is omitted, the session name is taken from the .lttngrc file.
6991b181
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987
988.B OPTIONS:
989
6c09bfdb
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990.TP
991.BR "\-h, \-\-help"
992Show summary of possible options and commands.
993.TP
994.BR "\-\-list-options"
995Simple listing of options
3a7a166e
MJ
996.TP
997.BR "\-\-no-wait"
6c09bfdb
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998Don't wait for data availability.
999.RE
1000.PP
6991b181 1001
5975c30a
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1002.PP
1003\fBversion\fP
1004.RS
6991b181 1005Show version information
6991b181
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1006
1007.B OPTIONS:
1008
5975c30a
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1009.TP
1010.BR "\-h, \-\-help"
1011Show summary of possible options and commands.
1012.TP
1013.BR "\-\-list-options"
1014Simple listing of options
1015.RE
1016.PP
6991b181 1017
5b4c1410
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1018.PP
1019\fBview\fP [SESSION_NAME] [OPTIONS]
1020.RS
1021View traces of a tracing session. By default, the babeltrace viewer
1022will be used for text viewing. If SESSION_NAME is omitted, the session
1023name is taken from the .lttngrc file.
6991b181
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1024
1025.B OPTIONS:
1026
5b4c1410
MD
1027.TP
1028.BR "\-h, \-\-help"
1029Show this help
1030.TP
1031.BR "\-\-list-options"
1032Simple listing of options
1033.TP
1034.BR "\-t, \-\-trace-path PATH"
1035Trace directory path for the viewer
1036.TP
1037.BR "\-e, \-\-viewer CMD"
1038Specify viewer and/or options to use This will completely override the
1039default viewers so please make sure to specify the full command. The
1040trace directory path of the session will be appended at the end to the
1041arguments
1042.RE
1043.PP
6991b181 1044
999ee001
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1045.SH "JUL/LOG4J DOMAIN"
1046
1047This section explains the JUL and LOG4J domain where JUL stands for Java Util
1048Logging. You can use these by using the \fBliblttng-ust-<domain>-jni.so\fP from
1049the lttng-ust(3) project.
acf47627
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1050
1051The LTTng Java Agent uses JNI to link the UST tracer to the Java application
1052that uses the agent. Thus, it behaves similarly to the UST domain (\-u). When
999ee001
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1053enabling events, you enable a Logger name that will then be mapped to a default
1054UST tracepoint called \fBlttng_jul:<domain>_event\fP in the
1055\fBlttng_<domain>_channel\fP. Using the lttng-ctl API, any JUL/LOG4J events
1056must use the tracepoint event type (same as \-\-tracepoint).
acf47627 1057
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1058Because of the default immutable channel, the \fBenable-channel\fP command CAN
1059NOT be used with the JUL and LOG4J domain thus not having any options.
acf47627 1060
999ee001
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1061Also, loglevels are supported. Use \fBlttng enable-event \-h\fP to list them.
1062Wildcards are NOT supported except the "*" meaning all events (same as \-a).
acf47627
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1063
1064Exactly like the UST domain, if the Java application has the same UID as you,
1065you can trace it. Same goes for the tracing group accessing root applications.
1066
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1067Finally, you can list every Logger name that are available from registered
1068applications to the session daemon by using \fBlttng list \-j\fP or \fB\-l\fP.
acf47627 1069
999ee001 1070Here is an example on how to use the JUL domain.
acf47627
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1071
1072.nf
1073$ lttng list -j
1074[...]
1075$ lttng create aSession
1076$ lttng enable-event -s aSession -j MyCustomLoggerName
1077$ lttng start
1078.fi
1079
1080More information can be found in the lttng-ust documentation, see
1081java-util-logging.txt
1082.PP
1083
c206d957 1084.SH "EXIT VALUES"
b107a0b1 1085.PP
6b8f2e64
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1086On success 0 is returned and a positive value on error. Value of 1 means a command
1087error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that
1088something went wrong during the command.
c206d957 1089
6b8f2e64 1090Any other value above 10, please refer to
b107a0b1 1091.BR "<lttng/lttng-error.h>"
6b8f2e64
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1092for a detailed list or use lttng_strerror() to get a human readable string of
1093the error code.
c206d957 1094.PP
b107a0b1 1095
6991b181
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1096.SH "ENVIRONMENT VARIABLES"
1097
1098.PP
1099Note that all command line options override environment variables.
1100.PP
1101
1102.PP
05833633 1103.IP "LTTNG_SESSIOND_PATH"
c9e32613
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1104Allows one to specify the full session daemon binary path to lttng command line
1105tool. You can also use \-\-sessiond-path option having the same effect.
b107a0b1
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1106.PP
1107
516f6cbe
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1108.PP
1109.IP "LTTNG_SESSION_CONFIG_XSD_PATH"
1110Set the path in which the \fBsession.xsd\fP session configuration schema may be
1111found.
1112.PP
1113
6991b181 1114.SH "SEE ALSO"
6b8f2e64
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1115.BR babeltrace(1),
1116.BR lttng-ust(3),
1117.BR lttng-sessiond(8),
1118.BR lttng-relayd(8),
b107a0b1 1119
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1120.SH "BUGS"
1121
b107a0b1 1122.PP
6991b181 1123If you encounter any issues or usability problem, please report it on our
6b8f2e64 1124mailing list <lttng-dev@lists.lttng.org> to help improve this project or
eb82f91d 1125at https://bugs.lttng.org which is a bug tracker.
b107a0b1
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1126.PP
1127
6991b181
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1128.SH "CREDITS"
1129
1130.PP
c9e32613 1131lttng is distributed under the GNU General Public License version 2. See the file
6991b181
DG
1132COPYING for details.
1133.PP
1134A Web site is available at http://lttng.org for more information on the LTTng
1135project.
1136.PP
1137You can also find our git tree at http://git.lttng.org.
1138.PP
1139Mailing lists for support and development: <lttng-dev@lists.lttng.org>.
1140.PP
1141You can find us on IRC server irc.oftc.net (OFTC) in #lttng.
1142.PP
1143.SH "THANKS"
1144
1145.PP
1146Thanks to Yannick Brosseau without whom this project would never have been so
1147lean and mean! Also thanks to the Ericsson teams working on tracing which
fa072eae 1148helped us greatly with detailed bug reports and unusual test cases.
6991b181
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1149
1150Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA
1151maintainer) and Jon Bernard for our Debian packages.
1152
1153Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de
1154Montreal for the LTTng journey.
c9e32613 1155.PP
6991b181
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1156.SH "AUTHORS"
1157
1158.PP
1159lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and
1160David Goulet. More people have since contributed to it. It is currently
9b22d135 1161maintained by Jérémie Galarneau <jeremie.galarneau@efficios.com>.
6991b181 1162.PP
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