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516f6cbe | 1 | .TH "LTTNG" "1" "May 13th, 2014" "" "" |
6991b181 DG |
2 | |
3 | .SH "NAME" | |
c5db699c | 4 | lttng \(em LTTng 2.x tracer control command line tool |
6991b181 DG |
5 | |
6 | .SH "SYNOPSIS" | |
7 | ||
8 | .PP | |
6991b181 | 9 | lttng [OPTIONS] <COMMAND> |
6991b181 DG |
10 | .SH "DESCRIPTION" |
11 | ||
12 | .PP | |
13 | The LTTng project aims at providing highly efficient tracing tools for Linux. | |
e256d661 | 14 | Its tracers help track down performance issues and debug problems |
6991b181 DG |
15 | involving multiple concurrent processes and threads. Tracing across multiple |
16 | systems is also possible. | |
17 | ||
fa072eae | 18 | The \fBlttng\fP command line tool from the lttng-tools package is used to control |
e256d661 JG |
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 | |
6991b181 DG |
21 | package. |
22 | ||
23 | LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry, | |
50a3b92a | 24 | which allows you to interact with multiple tracers (kernel and user-space) |
6991b181 DG |
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. | |
28 | ||
50a3b92a | 29 | We introduce the notion of \fBtracing domains\fP which is essentially a type of |
0e115563 DG |
30 | tracer (kernel, user space, JUL, LOG4J or Python for now). In the future, we |
31 | could see more tracer like for instance an hypervisor. For some commands, | |
32 | you'll need to specify on which domain the command operates (\-u, \-k, \-l, \-j | |
33 | or \-p). For instance, the kernel domain must be specified when enabling a | |
34 | kernel event. | |
50a3b92a | 35 | |
6991b181 DG |
36 | In order to trace the kernel, the session daemon needs to be running as root. |
37 | LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is | |
38 | in that group can interact with the root session daemon and thus trace the | |
e256d661 | 39 | kernel. Session daemons can co-exist, meaning that you can have a session daemon |
fa072eae | 40 | running as Alice that can be used to trace her applications along side with a |
e256d661 | 41 | root daemon or even a Bob daemon. We highly recommend starting the session |
6991b181 DG |
42 | daemon at boot time for stable and long term tracing. |
43 | ||
274d6c5d DG |
44 | Each user-space application instrumented with lttng-ust(3) will automatically |
45 | register with the root session daemon and its user session daemon. This allows | |
46 | each daemon to list the available traceable applications and tracepoints at any | |
47 | given moment (See the \fBlist\fP command). | |
6991b181 DG |
48 | .SH "OPTIONS" |
49 | ||
50 | .PP | |
51 | This program follow the usual GNU command line syntax with long options starting with | |
52 | two dashes. Below is a summary of the available options. | |
53 | .PP | |
54 | ||
55 | .TP | |
c9e32613 | 56 | .BR "\-h, \-\-help" |
6991b181 DG |
57 | Show summary of possible options and commands. |
58 | .TP | |
c9e32613 | 59 | .BR "\-v, \-\-verbose" |
6991b181 | 60 | Increase verbosity. |
d829b38c | 61 | Three levels of verbosity are available which are triggered by putting additional v to |
fa072eae | 62 | the option (\-vv or \-vvv) |
6991b181 | 63 | .TP |
c9e32613 | 64 | .BR "\-q, \-\-quiet" |
6991b181 DG |
65 | Suppress all messages (even errors). |
66 | .TP | |
c9e32613 | 67 | .BR "\-g, \-\-group NAME" |
6991b181 DG |
68 | Set unix tracing group name. (default: tracing) |
69 | .TP | |
c9e32613 | 70 | .BR "\-n, \-\-no-sessiond" |
6991b181 DG |
71 | Don't automatically spawn a session daemon. |
72 | .TP | |
391b9c72 | 73 | .BR "\-\-sessiond\-path PATH" |
6991b181 DG |
74 | Set session daemon full binary path. |
75 | .TP | |
c9e32613 | 76 | .BR "\-\-list\-options" |
6991b181 DG |
77 | Simple listing of lttng options. |
78 | .TP | |
c9e32613 | 79 | .BR "\-\-list\-commands" |
6991b181 | 80 | Simple listing of lttng commands. |
ed43168a JRJ |
81 | .TP |
82 | .BR "\-m, \-\-mi TYPE | |
83 | Machine interface | |
84 | ||
85 | TYPE supported: XML | |
86 | ||
87 | Machine interface (MI) mode converts the traditional pretty printing to a | |
88 | machine output syntax. MI mode provides a format change-resistant way to access | |
89 | information generated via the lttng command line. | |
90 | ||
91 | When using MI mode, the data is printed on \fBstdout\fP. Error and warning are | |
92 | printed on \fBstderr\fP with the pretty print default format. | |
93 | ||
94 | If any errors occur during the execution of a command, the return value of the | |
95 | command will be different than zero. In this case, lttng does NOT guarantee the | |
96 | syntax and data validity of the generated MI output. | |
97 | ||
98 | For XML output type, a schema definition (XSD) file used for validation can be | |
99 | found under src/common/mi_lttng.xsd | |
100 | ||
6991b181 DG |
101 | .SH "COMMANDS" |
102 | ||
812a5eb7 | 103 | .PP |
ee2758e5 | 104 | \fBadd-context\fP [OPTIONS] |
812a5eb7 | 105 | .RS |
6991b181 DG |
106 | Add context to event(s) and/or channel(s). |
107 | ||
391b9c72 DG |
108 | A context is basically extra information appended to a channel. For instance, |
109 | you could ask the tracer to add the PID information for all events in a | |
110 | channel. You can also add performance monitoring unit counters (perf PMU) using | |
aa3514e9 | 111 | the perf kernel API. |
6991b181 | 112 | |
aa3514e9 MD |
113 | For example, this command will add the context information 'prio' and two per-CPU |
114 | perf counters (hardware branch misses and cache misses), to all events in the trace | |
6991b181 DG |
115 | data output: |
116 | ||
812a5eb7 | 117 | .nf |
aa3514e9 MD |
118 | # lttng add-context \-k \-t prio \-t perf:cpu:branch-misses \\ |
119 | \-t perf:cpu:cache-misses | |
812a5eb7 | 120 | .fi |
6991b181 | 121 | |
c9e32613 | 122 | Please take a look at the help (\-h/\-\-help) for a detailed list of available |
6991b181 DG |
123 | contexts. |
124 | ||
aa3514e9 MD |
125 | Perf counters are available as per-CPU ("perf:cpu:...") and per-thread |
126 | ("perf:thread:...") counters. Currently, per-CPU counters can only be | |
127 | used with the kernel tracing domain, and per-thread counters can only be | |
128 | used with the UST tracing domain. | |
129 | ||
bd337b98 DG |
130 | If no channel is given (\-c), the context is added to all channels that were |
131 | already enabled. If the session has no channel, a default channel is created. | |
31ea4846 | 132 | Otherwise the context will be added only to the given channel (\-c). |
6991b181 | 133 | |
c9e32613 | 134 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 135 | file. |
6991b181 DG |
136 | |
137 | .B OPTIONS: | |
138 | ||
812a5eb7 MD |
139 | .TP |
140 | .BR "\-h, \-\-help" | |
141 | Show summary of possible options and commands. | |
142 | .TP | |
143 | .BR "\-s, \-\-session NAME" | |
144 | Apply on session name. | |
145 | .TP | |
146 | .BR "\-c, \-\-channel NAME" | |
147 | Apply on channel name. | |
148 | .TP | |
149 | .BR "\-k, \-\-kernel" | |
150 | Apply for the kernel tracer | |
151 | .TP | |
152 | .BR "\-u, \-\-userspace" | |
153 | Apply for the user-space tracer | |
154 | .TP | |
155 | .BR "\-t, \-\-type TYPE" | |
156 | Context type. You can repeat this option on the command line. Please | |
157 | use "lttng add-context \-h" to list all available types. | |
158 | .RE | |
159 | .PP | |
6991b181 | 160 | |
22019883 MD |
161 | .PP |
162 | \fBcalibrate\fP [OPTIONS] | |
163 | .RS | |
6991b181 DG |
164 | Quantify LTTng overhead |
165 | ||
166 | The LTTng calibrate command can be used to find out the combined average | |
167 | overhead of the LTTng tracer and the instrumentation mechanisms used. This | |
168 | overhead can be calibrated in terms of time or using any of the PMU performance | |
169 | counter available on the system. | |
170 | ||
171 | For now, the only calibration implemented is that of the kernel function | |
172 | instrumentation (kretprobes). | |
173 | ||
174 | * Calibrate kernel function instrumentation | |
175 | ||
176 | Let's use an example to show this calibration. We use an i7 processor with 4 | |
177 | general-purpose PMU registers. This information is available by issuing dmesg, | |
178 | looking for "generic registers". | |
179 | ||
180 | This sequence of commands will gather a trace executing a kretprobe hooked on | |
181 | an empty function, gathering PMU counters LLC (Last Level Cache) misses | |
c9e32613 | 182 | information (see lttng add-context \-\-help to see the list of available PMU |
6991b181 DG |
183 | counters). |
184 | ||
22019883 | 185 | .nf |
6991b181 | 186 | # lttng create calibrate-function |
22019883 MD |
187 | # lttng enable-event calibrate \-\-kernel \\ |
188 | \-\-function lttng_calibrate_kretprobe | |
aa3514e9 MD |
189 | # lttng add-context \-\-kernel \-t perf:cpu:LLC-load-misses \\ |
190 | \-t perf:cpu:LLC-store-misses \\ | |
191 | \-t perf:cpu:LLC-prefetch-misses | |
6991b181 DG |
192 | # lttng start |
193 | # for a in $(seq 1 10); do \\ | |
c9e32613 | 194 | lttng calibrate \-\-kernel \-\-function; |
6991b181 DG |
195 | done |
196 | # lttng destroy | |
22019883 MD |
197 | # babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\ |
198 | | tail \-n 1) | |
199 | .fi | |
6991b181 DG |
200 | |
201 | The output from babeltrace can be saved to a text file and opened in a | |
202 | spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between | |
203 | consecutive "calibrate_entry" and "calibrate_return" events. Note that these | |
204 | counters are per-CPU, so scheduling events would need to be present to account | |
205 | for migration between CPU. Therefore, for calibration purposes, only events | |
206 | staying on the same CPU must be considered. | |
207 | ||
208 | The average result, for the i7, on 10 samples: | |
209 | ||
22019883 | 210 | .nf |
6991b181 DG |
211 | Average Std.Dev. |
212 | perf_LLC_load_misses: 5.0 0.577 | |
213 | perf_LLC_store_misses: 1.6 0.516 | |
214 | perf_LLC_prefetch_misses: 9.0 14.742 | |
22019883 | 215 | .fi |
6991b181 DG |
216 | |
217 | As we can notice, the load and store misses are relatively stable across runs | |
218 | (their standard deviation is relatively low) compared to the prefetch misses. | |
219 | We can conclude from this information that LLC load and store misses can be | |
220 | accounted for quite precisely, but prefetches within a function seems to behave | |
221 | too erratically (not much causality link between the code executed and the CPU | |
222 | prefetch activity) to be accounted for. | |
6991b181 DG |
223 | |
224 | .B OPTIONS: | |
225 | ||
22019883 MD |
226 | .TP |
227 | .BR "\-h, \-\-help" | |
228 | Show summary of possible options and commands. | |
229 | .TP | |
230 | .BR "\-k, \-\-kernel" | |
231 | Apply for the kernel tracer | |
232 | .TP | |
233 | .BR "\-u, \-\-userspace" | |
234 | Apply for the user-space tracer | |
235 | .TP | |
236 | .BR "\-\-function" | |
237 | Dynamic function entry/return probe (default) | |
238 | .RE | |
239 | .PP | |
6991b181 | 240 | |
ee2758e5 | 241 | .PP |
feb3ca56 | 242 | \fBcreate\fP [NAME] [OPTIONS] |
ee2758e5 | 243 | .RS |
6991b181 DG |
244 | Create tracing session. |
245 | ||
246 | A tracing session contains channel(s) which contains event(s). It is domain | |
e256d661 | 247 | agnostic, meaning that channels and events can be enabled for the |
6991b181 DG |
248 | user-space tracer and/or the kernel tracer. It acts like a container |
249 | aggregating multiple tracing sources. | |
250 | ||
251 | On creation, a \fB.lttngrc\fP file is created in your $HOME directory | |
252 | containing the current session name. If NAME is omitted, a session name is | |
fa072eae | 253 | automatically created having this form: 'auto-yyyymmdd-hhmmss'. |
6991b181 | 254 | |
c9e32613 | 255 | If no \fB\-o, \-\-output\fP is specified, the traces will be written in |
6991b181 | 256 | $HOME/lttng-traces. |
feb0f3e5 AM |
257 | |
258 | The $HOME environment variable can be overridden by defining the environment | |
259 | variable LTTNG_HOME. This is useful when the user running the commands has | |
260 | a non-writeable home directory. | |
6991b181 | 261 | |
1c1c3634 DG |
262 | The session name MUST NOT contain the character '/'. |
263 | ||
6991b181 DG |
264 | .B OPTIONS: |
265 | ||
ee2758e5 MD |
266 | .TP |
267 | .BR "\-h, \-\-help" | |
268 | Show summary of possible options and commands. | |
269 | .TP | |
270 | .BR "\-\-list-options" | |
271 | Simple listing of options | |
272 | .TP | |
273 | .BR "\-o, \-\-output PATH" | |
274 | Specify output path for traces | |
275 | .TP | |
96fe6b8d DG |
276 | .BR "\-\-no-output" |
277 | Traces will not be output | |
278 | .TP | |
ee2758e5 | 279 | .BR "\-\-snapshot" |
96fe6b8d DG |
280 | Set the session in snapshot mode. Created in no-output mode and uses the |
281 | URL, if one is specified, as the default snapshot output. Every channel will be set | |
ee2758e5 | 282 | in overwrite mode and with mmap output (splice not supported). |
0794f51b | 283 | .TP |
d73c5802 | 284 | .BR "\-\-live [USEC]" |
eb82f91d | 285 | Set the session exclusively in live mode. The parameter is the delay in micro |
0794f51b DG |
286 | seconds before the data is flushed and streamed. The live mode allows you to |
287 | stream the trace and view it while it's being recorded by any tracer. For that, | |
288 | you need a lttng-relayd and this session requires a network URL (\-U or | |
d73c5802 DG |
289 | \-C/\-D). If no USEC nor URL is provided, the default is to use a timer value |
290 | set to 1000000 and the network URL set to net://127.0.0.1. | |
0794f51b DG |
291 | |
292 | To read a live session, you can use babeltrace(1) or the live streaming | |
293 | protocol in doc/live-reading-protocol.txt. Here is an example: | |
294 | ||
295 | .nf | |
296 | $ lttng-relayd -o /tmp/lttng | |
297 | $ lttng create --live 200000 -U net://localhost | |
298 | $ lttng enable-event -a --userspace | |
299 | $ lttng start | |
300 | .fi | |
301 | ||
302 | After the start, you'll be able to read the events while they are being | |
303 | recorded in /tmp/lttng. | |
6b8f2e64 | 304 | |
ee2758e5 MD |
305 | .TP |
306 | .BR "\-U, \-\-set-url=URL" | |
307 | Set URL for the consumer output destination. It is persistent for the | |
308 | session lifetime. Redo the command to change it. This will set both data | |
309 | and control URL for network. | |
310 | .TP | |
311 | .BR "\-C, \-\-ctrl-url=URL" | |
312 | Set control path URL. (Must use -D also) | |
313 | .TP | |
314 | .BR "\-D, \-\-data-url=URL" | |
315 | Set data path URL. (Must use -C also) | |
316 | .PP | |
6b8f2e64 DG |
317 | Using these options, each API call can be controlled individually. For |
318 | instance, \-C does not enable the consumer automatically. You'll need the \-e | |
319 | option for that. | |
320 | ||
785d2d0d DG |
321 | .B URL FORMAT: |
322 | ||
323 | proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH] | |
324 | ||
325 | Supported protocols are (proto): | |
ee2758e5 MD |
326 | .TP |
327 | .BR "file://..." | |
328 | Local filesystem full path. | |
785d2d0d | 329 | |
ee2758e5 MD |
330 | .TP |
331 | .BR "net://..." | |
332 | This will use the default network transport layer which is TCP for both | |
333 | control (PORT1) and data port (PORT2). The default ports are | |
334 | respectively 5342 and 5343. Note that net[6]:// is not yet supported. | |
785d2d0d | 335 | |
ee2758e5 MD |
336 | .TP |
337 | .BR "tcp[6]://..." | |
338 | Can only be used with -C and -D together | |
785d2d0d DG |
339 | |
340 | NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732) | |
6b8f2e64 DG |
341 | |
342 | .B EXAMPLES: | |
343 | ||
ee2758e5 | 344 | .nf |
6b8f2e64 | 345 | # lttng create -U net://192.168.1.42 |
ee2758e5 | 346 | .fi |
6b8f2e64 DG |
347 | Uses TCP and default ports for the given destination. |
348 | ||
ee2758e5 | 349 | .nf |
6b8f2e64 | 350 | # lttng create -U net6://[fe80::f66d:4ff:fe53:d220] |
ee2758e5 | 351 | .fi |
6b8f2e64 DG |
352 | Uses TCP, default ports and IPv6. |
353 | ||
ee2758e5 | 354 | .nf |
6b8f2e64 | 355 | # lttng create s1 -U net://myhost.com:3229 |
6991b181 | 356 | .fi |
ee2758e5 MD |
357 | Create session s1 and set its consumer to myhost.com on port 3229 for control. |
358 | .RE | |
359 | .PP | |
6991b181 | 360 | |
f2b14ef1 MD |
361 | .PP |
362 | \fBdestroy\fP [NAME] [OPTIONS] | |
363 | .RS | |
6991b181 DG |
364 | Teardown tracing session |
365 | ||
366 | Free memory on the session daemon and tracer side. It's gone! | |
367 | ||
368 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
369 | |
370 | .B OPTIONS: | |
371 | ||
f2b14ef1 MD |
372 | .TP |
373 | .BR "\-h, \-\-help" | |
374 | Show summary of possible options and commands. | |
375 | .TP | |
376 | .BR "\-a, \-\-all" | |
377 | Destroy all sessions | |
378 | .TP | |
379 | .BR "\-\-list-options" | |
380 | Simple listing of options | |
381 | .RE | |
382 | .PP | |
6991b181 | 383 | |
05be3802 MD |
384 | .PP |
385 | \fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
386 | .RS | |
6991b181 DG |
387 | Enable tracing channel |
388 | ||
004f3466 DG |
389 | To enable an event, you must enable both the event and the channel that |
390 | contains it. | |
b883c01b | 391 | |
c9e32613 | 392 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 393 | file. |
7972aab2 | 394 | |
05be3802 MD |
395 | Exactly one of \-k or -u must be specified. |
396 | ||
7972aab2 | 397 | It is important to note that if a certain type of buffers is used, the session |
bd337b98 | 398 | will be set with that type and all other subsequent channel needs to have the |
7972aab2 | 399 | same type. |
bd337b98 | 400 | |
d2f11c4a DG |
401 | Note that once the session has been started and enabled on the tracer side, |
402 | it's not possible anymore to enable a new channel for that session. | |
6991b181 DG |
403 | |
404 | .B OPTIONS: | |
405 | ||
05be3802 MD |
406 | .TP |
407 | .BR "\-h, \-\-help" | |
408 | Show this help | |
409 | .TP | |
410 | .BR "\-\-list-options" | |
411 | Simple listing of options | |
412 | .TP | |
413 | .BR "\-s, \-\-session NAME" | |
414 | Apply on session name | |
415 | .TP | |
416 | .BR "\-k, \-\-kernel" | |
417 | Apply to the kernel tracer | |
418 | .TP | |
419 | .BR "\-u, \-\-userspace" | |
420 | Apply to the user-space tracer | |
421 | .TP | |
422 | .BR "\-\-discard" | |
423 | Discard event when subbuffers are full (default) | |
424 | .TP | |
425 | .BR "\-\-overwrite" | |
33fbd469 DG |
426 | Flight recorder mode: overwrites events when subbuffers are full. The |
427 | number of subbuffer must be 2 or more. | |
05be3802 MD |
428 | .TP |
429 | .BR "\-\-subbuf-size SIZE" | |
430 | Subbuffer size in bytes {+k,+M,+G}. | |
431 | (default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096) | |
432 | Rounded up to the next power of 2. | |
433 | ||
434 | The minimum subbuffer size, for each tracer, is the max value between | |
435 | the default above and the system page size. You can issue this command | |
436 | to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP | |
437 | .TP | |
438 | .BR "\-\-num-subbuf NUM" | |
439 | Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4, | |
440 | metadata: 2) Rounded up to the next power of 2. | |
441 | .TP | |
442 | .BR "\-\-switch-timer USEC" | |
443 | Switch subbuffer timer interval in µsec. | |
444 | (default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0) | |
445 | .TP | |
446 | .BR "\-\-read-timer USEC" | |
447 | Read timer interval in µsec. | |
448 | (default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0) | |
449 | .TP | |
450 | .BR "\-\-output TYPE" | |
451 | Channel output type. Possible values: mmap, splice | |
452 | (default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap) | |
453 | .TP | |
454 | .BR "\-\-buffers-uid" | |
455 | Use per UID buffer (\-u only). Buffers are shared between applications | |
456 | that have the same UID. | |
457 | .TP | |
458 | .BR "\-\-buffers-pid" | |
459 | Use per PID buffer (\-u only). Each application has its own buffers. | |
460 | .TP | |
461 | .BR "\-\-buffers-global" | |
462 | Use shared buffer for the whole system (\-k only) | |
463 | .TP | |
464 | .BR "\-C, \-\-tracefile-size SIZE" | |
465 | Maximum size of each tracefile within a stream (in bytes). | |
466 | 0 means unlimited. (default: 0) | |
c0684a0d | 467 | Note: traces generated with this option may inaccurately report |
a10f04ad | 468 | discarded events as of CTF 1.8. |
05be3802 MD |
469 | .TP |
470 | .BR "\-W, \-\-tracefile-count COUNT" | |
471 | Used in conjunction with \-C option, this will limit the number of files | |
472 | created to the specified count. 0 means unlimited. (default: 0) | |
1624d5b7 JD |
473 | |
474 | .B EXAMPLES: | |
475 | ||
05be3802 MD |
476 | .nf |
477 | $ lttng enable-channel -k -C 4096 -W 32 chan1 | |
478 | .fi | |
e256d661 | 479 | For each stream, the maximum size of each trace file will be 4096 bytes and |
cea28771 | 480 | there will be a maximum of 32 different files. The file count is appended after |
1624d5b7 JD |
481 | the stream number as seen in the following example. The last trace file is |
482 | smaller than 4096 since it was not completely filled. | |
483 | ||
05be3802 | 484 | .nf |
1624d5b7 JD |
485 | ~/lttng-traces/[...]/chan1_0_0 (4096) |
486 | ~/lttng-traces/[...]/chan1_0_1 (4096) | |
487 | ~/lttng-traces/[...]/chan1_0_2 (3245) | |
488 | ~/lttng-traces/[...]/chan1_1_0 (4096) | |
489 | ... | |
05be3802 | 490 | .fi |
1624d5b7 | 491 | |
05be3802 MD |
492 | .nf |
493 | $ lttng enable-channel -k -C 4096 | |
494 | .fi | |
1624d5b7 JD |
495 | This will create trace files of 4096 bytes and will create new ones as long as |
496 | there is data available. | |
05be3802 MD |
497 | .RE |
498 | .PP | |
6991b181 | 499 | |
6a240cd9 MD |
500 | .PP |
501 | \fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS] | |
502 | .RS | |
6991b181 DG |
503 | Enable tracing event |
504 | ||
c9e32613 | 505 | A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is |
6991b181 | 506 | omitted, a default channel named '\fBchannel0\fP' is created and the event is |
85076754 MD |
507 | added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default |
508 | channel already exists within the session, an error is returned. For the | |
509 | user-space tracer, using \fB\-a, \-\-all\fP is the same as using the | |
510 | wildcard "*". | |
6991b181 | 511 | |
c9e32613 | 512 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 513 | file. |
6991b181 DG |
514 | |
515 | .B OPTIONS: | |
516 | ||
6a240cd9 MD |
517 | .TP |
518 | .BR "\-h, \-\-help" | |
519 | Show summary of possible options and commands. | |
520 | .TP | |
521 | .BR "\-\-list-options" | |
522 | Simple listing of options | |
523 | .TP | |
524 | .BR "\-s, \-\-session NAME" | |
525 | Apply on session name | |
526 | .TP | |
527 | .BR "\-c, \-\-channel NAME" | |
528 | Apply on channel name | |
529 | .TP | |
530 | .BR "\-a, \-\-all" | |
e256d661 | 531 | Enable all tracepoints and syscalls. This actually enables a single |
6a240cd9 MD |
532 | wildcard event "*". |
533 | .TP | |
534 | .BR "\-k, \-\-kernel" | |
535 | Apply for the kernel tracer | |
536 | .TP | |
537 | .BR "\-u, \-\-userspace" | |
538 | Apply for the user-space tracer | |
539 | .TP | |
bed69e7d DG |
540 | .BR "\-j, \-\-jul" |
541 | Apply for Java application using Java Util Logging interface (JUL) | |
542 | .TP | |
222e4eab DG |
543 | .BR "\-l, \-\-log4j" |
544 | Apply for Java application using LOG4J | |
545 | .TP | |
0e115563 DG |
546 | .BR "\-p, \-\-python" |
547 | Apply for Python application using the logging module. | |
548 | .TP | |
6a240cd9 | 549 | .BR "\-\-tracepoint" |
e256d661 | 550 | Tracepoint event (default). Userspace tracer supports wildcards at the end |
6a240cd9 MD |
551 | of string. Don't forget to quote to deal with bash expansion. |
552 | e.g.: | |
6991b181 | 553 | .nf |
6991b181 DG |
554 | "*" |
555 | "app_component:na*" | |
6991b181 | 556 | .fi |
6a240cd9 MD |
557 | .TP |
558 | .BR "\-\-loglevel NAME" | |
559 | Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h). | |
f9e8873b DG |
560 | For the JUL domain, the loglevel ranges are detailed with the \-\-help |
561 | option thus starting from SEVERE to FINEST. | |
999ee001 DG |
562 | For the LOG4J domain, loglevels range from FATAL to TRACE which are also |
563 | detailed in the help. | |
0e115563 DG |
564 | For the Python domain, loglevels range from CRITICAL to DEBUG which are |
565 | detailed in the help as well. | |
6a240cd9 MD |
566 | .TP |
567 | .BR "\-\-loglevel-only NAME" | |
568 | Tracepoint loglevel (only this loglevel). | |
569 | The loglevel or loglevel-only options should be combined with a | |
570 | tracepoint name or tracepoint wildcard. | |
571 | .TP | |
572 | .BR "\-\-probe (addr | symbol | symbol+offset)" | |
573 | Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...) | |
574 | or hexadecimal (0xNNN...) | |
575 | .TP | |
576 | .BR "\-\-function (addr | symbol | symbol+offset)" | |
577 | Dynamic function entry/return probe. Addr and offset can be octal | |
578 | (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...) | |
579 | .TP | |
580 | .BR "\-\-syscall" | |
581 | System call event. Enabling syscalls tracing (kernel tracer), you will | |
582 | not be able to disable them with disable-event. This is a known | |
627dbfd8 CB |
583 | limitation. You can disable the entire channel to do the trick. Also note |
584 | that per-syscall selection is not supported yet. Use with "-a" to enable | |
585 | all syscalls. | |
6a240cd9 MD |
586 | .TP |
587 | .BR "\-\-filter 'expression'" | |
588 | Set a filter on a newly enabled event. Filter expression on event | |
e256d661 JG |
589 | fields and context. The event will be recorded if the filter's |
590 | expression evaluates to TRUE. Only specify on first activation of a | |
591 | given event within a session. | |
592 | Specifying a filter is only allowed when enabling events within a session before | |
6a240cd9 MD |
593 | tracing is started. If the filter fails to link with the event |
594 | within the traced domain, the event will be discarded. | |
e256d661 | 595 | Filtering is currently only implemented for the user-space tracer. |
6a240cd9 MD |
596 | |
597 | Expression examples: | |
598 | ||
599 | .nf | |
600 | 'intfield > 500 && intfield < 503' | |
601 | '(strfield == "test" || intfield != 10) && intfield > 33' | |
602 | 'doublefield > 1.1 && intfield < 5.3' | |
603 | .fi | |
604 | ||
605 | Wildcards are allowed at the end of strings: | |
606 | 'seqfield1 == "te*"' | |
607 | In string literals, the escape character is a '\\'. Use '\\*' for | |
e256d661 JG |
608 | the '*' character, and '\\\\' for the '\\' character sequence. Wildcard |
609 | matches any sequence of characters, including an empty sub-string | |
610 | (matches 0 or more characters). | |
6a240cd9 | 611 | |
e256d661 JG |
612 | Context information can be used for filtering. The examples below shows |
613 | usage of context filtering on the process name (using a wildcard), process ID | |
614 | range, and unique thread ID. The process and thread IDs of | |
6a240cd9 MD |
615 | running applications can be found under columns "PID" and "LWP" of the |
616 | "ps -eLf" command. | |
617 | ||
618 | .nf | |
619 | '$ctx.procname == "demo*"' | |
620 | '$ctx.vpid >= 4433 && $ctx.vpid < 4455' | |
621 | '$ctx.vtid == 1234' | |
622 | .fi | |
623 | ||
11139b74 DG |
624 | Context information is available to all filters whether or not the add-context |
625 | command has been used to add it to the event's channel, as long as the context | |
626 | field exists for that domain. For example, the filter examples given above will | |
627 | never fail to link: no add-context is required for the event's channel. | |
628 | ||
bccd20a3 JI |
629 | .TP |
630 | .BR "\-x, \-\-exclude LIST" | |
631 | Add exclusions to UST tracepoints: | |
632 | Events that match any of the items in the comma-separated LIST are not | |
633 | enabled, even if they match a wildcard definition of the event. | |
634 | ||
635 | This option is also applicable with the \fB\-a, \-\-all\fP option, | |
636 | in which case all UST tracepoints are enabled except the ones whose | |
637 | names match any of the items in LIST. | |
6a240cd9 MD |
638 | .RE |
639 | .PP | |
6991b181 | 640 | |
272c6a17 MD |
641 | .PP |
642 | \fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
643 | .RS | |
6991b181 DG |
644 | Disable tracing channel |
645 | ||
e256d661 | 646 | Disabling a channel disables the tracing of all of the channel's events. A channel |
5368d366 | 647 | can be re-enabled by calling \fBlttng enable-channel NAME\fP again. |
6991b181 | 648 | |
c9e32613 | 649 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 650 | file. |
6991b181 DG |
651 | |
652 | .B OPTIONS: | |
653 | ||
272c6a17 MD |
654 | .TP |
655 | .BR "\-h, \-\-help" | |
656 | Show summary of possible options and commands. | |
657 | .TP | |
658 | .BR "\-\-list-options" | |
659 | Simple listing of options | |
660 | .TP | |
661 | .BR "\-s, \-\-session NAME" | |
662 | Apply on session name | |
663 | .TP | |
664 | .BR "\-k, \-\-kernel" | |
665 | Apply for the kernel tracer | |
666 | .TP | |
667 | .BR "\-u, \-\-userspace" | |
668 | Apply for the user-space tracer | |
669 | .RE | |
670 | .PP | |
6991b181 | 671 | |
c138a39b MD |
672 | .PP |
673 | \fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
674 | .RS | |
6991b181 DG |
675 | Disable tracing event |
676 | ||
677 | The event, once disabled, can be re-enabled by calling \fBlttng enable-event | |
678 | NAME\fP again. | |
679 | ||
c9e32613 | 680 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 681 | file. |
6991b181 | 682 | |
85076754 MD |
683 | If \fB\-c, \-\-channel\fP is omitted, the default channel name is used. |
684 | If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already | |
685 | exists within the session, an error is returned. | |
686 | ||
6991b181 DG |
687 | .B OPTIONS: |
688 | ||
c138a39b MD |
689 | .TP |
690 | .BR "\-h, \-\-help" | |
691 | Show summary of possible options and commands. | |
692 | .TP | |
693 | .BR "\-\-list-options" | |
694 | Simple listing of options | |
695 | .TP | |
696 | .BR "\-s, \-\-session NAME" | |
697 | Apply on session name | |
698 | .TP | |
85076754 MD |
699 | .BR "\-c, \-\-channel NAME" |
700 | Apply on channel name | |
701 | .TP | |
c138a39b MD |
702 | .BR "\-a, \-\-all-events" |
703 | Disable all events. This does NOT disable "*" but rather every known | |
704 | events of the session. | |
705 | .TP | |
706 | .BR "\-k, \-\-kernel" | |
707 | Apply for the kernel tracer | |
708 | .TP | |
709 | .BR "\-u, \-\-userspace" | |
710 | Apply for the user-space tracer | |
bed69e7d DG |
711 | .TP |
712 | .BR "\-j, \-\-jul" | |
713 | Apply for Java application using Java Util Logging interface (JUL) | |
222e4eab DG |
714 | .TP |
715 | .BR "\-l, \-\-log4j" | |
716 | Apply for Java application using LOG4J | |
0e115563 DG |
717 | .TP |
718 | .BR "\-p, \-\-python" | |
719 | Apply for Python application using the logging module. | |
c138a39b MD |
720 | .RE |
721 | .PP | |
6991b181 | 722 | |
747361fe MD |
723 | .PP |
724 | \fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]] | |
725 | .RS | |
c9e32613 | 726 | List tracing session information. |
6991b181 DG |
727 | |
728 | With no arguments, it will list available tracing session(s). | |
729 | ||
fa072eae YB |
730 | With the session name, it will display the details of the session including |
731 | the trace file path, the associated channels and their state (activated | |
d829b38c | 732 | and deactivated), the activated events and more. |
fa072eae | 733 | |
c9e32613 | 734 | With \-k alone, it will list all available kernel events (except the system |
6991b181 | 735 | calls events). |
bed69e7d DG |
736 | With \-j alone, the available JUL event from registered application will be |
737 | list. The event corresponds to the Logger name in the Java JUL application. | |
999ee001 DG |
738 | With \-l alone, the available LOG4J event from registered application will be |
739 | list. The event corresponds to the Logger name in the Java LOG4J application. | |
0e115563 DG |
740 | With \-p alone, the available Python event from registered application will be |
741 | list. The event corresponds to the Logger name in the Python application. | |
c9e32613 DG |
742 | With \-u alone, it will list all available user-space events from registered |
743 | applications. Here is an example of 'lttng list \-u': | |
6991b181 | 744 | |
747361fe | 745 | .nf |
6991b181 DG |
746 | PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello |
747 | ust_tests_hello:tptest_sighandler (type: tracepoint) | |
748 | ust_tests_hello:tptest (type: tracepoint) | |
747361fe | 749 | .fi |
6991b181 DG |
750 | |
751 | You can now enable any event listed by using the name : | |
752 | \fBust_tests_hello:tptest\fP. | |
6991b181 DG |
753 | |
754 | .B OPTIONS: | |
755 | ||
747361fe MD |
756 | .TP |
757 | .BR "\-h, \-\-help" | |
758 | Show summary of possible options and commands. | |
759 | .TP | |
760 | .BR "\-\-list-options" | |
761 | Simple listing of options | |
762 | .TP | |
763 | .BR "\-k, \-\-kernel" | |
764 | Select kernel domain | |
765 | .TP | |
766 | .BR "\-u, \-\-userspace" | |
767 | Select user-space domain. | |
bed69e7d DG |
768 | .TP |
769 | .BR "\-j, \-\-jul" | |
770 | Apply for Java application using JUL | |
771 | .TP | |
222e4eab DG |
772 | .BR "\-l, \-\-log4j" |
773 | Apply for Java application using LOG4J | |
0e115563 DG |
774 | .TP |
775 | .BR "\-p, \-\-python" | |
776 | Apply for Python application using the logging module. | |
777 | .TP | |
bed69e7d DG |
778 | .BR "\-f, \-\-fields" |
779 | List event fields | |
6991b181 | 780 | |
747361fe | 781 | .PP |
6b8f2e64 DG |
782 | .B SESSION OPTIONS: |
783 | ||
747361fe MD |
784 | .TP |
785 | .BR "\-c, \-\-channel NAME" | |
786 | List details of a channel | |
787 | .TP | |
788 | .BR "\-d, \-\-domain" | |
789 | List available domain(s) | |
790 | .RE | |
791 | .PP | |
6991b181 | 792 | |
516f6cbe JG |
793 | .PP |
794 | \fBload\fP [OPTIONS] [NAME] | |
795 | .RS | |
796 | Load tracing session configuration | |
797 | ||
798 | If NAME is omitted, all session configurations found in both the user's session | |
bd88d988 | 799 | configuration directory (default: ~/.lttng/sessions/) and the system session |
cf53c06d DG |
800 | configuration directory (default: /etc/lttng/sessions/) will be loaded. Note |
801 | that the sessions in the user directory are loaded first and then the system | |
802 | wide directory are loaded. | |
516f6cbe JG |
803 | |
804 | .B OPTIONS: | |
805 | ||
806 | .TP | |
807 | .BR "\-h, \-\-help" | |
808 | Show summary of possible options and commands. | |
809 | .TP | |
810 | .BR "\-a, \-\-all" | |
811 | Load all session configurations (default). | |
812 | .TP | |
813 | .BR "\-i, \-\-input-path PATH" | |
bd88d988 DG |
814 | Specify the input path for session configurations. This overrides the default |
815 | session configuration directory. | |
516f6cbe JG |
816 | .TP |
817 | .BR "\-f, -\-force" | |
818 | Overwrite current session configuration(s) if a session of the same name | |
819 | already exists. | |
820 | .RE | |
821 | .PP | |
822 | ||
823 | .PP | |
824 | \fBsave\fP [OPTIONS] [SESSION] | |
825 | .RS | |
826 | Save tracing session configuration | |
827 | ||
828 | If SESSION is omitted, all session configurations will be saved to individual | |
553067af | 829 | \fB.lttng\fP files under the user's session configuration directory (default: |
bd88d988 DG |
830 | ~/.lttng/sessions/). The default session configuration file naming scheme is |
831 | \fBSESSION.lttng\fP. | |
516f6cbe | 832 | |
cf53c06d DG |
833 | For instance, a user in the tracing group saving a session from a root session |
834 | daemon will save it in her/his user directory. | |
835 | ||
516f6cbe JG |
836 | .B OPTIONS: |
837 | ||
838 | .TP | |
839 | .BR "\-h, \-\-help" | |
840 | Show summary of possible options and commands. | |
841 | .TP | |
842 | .BR "\-a, \-\-all" | |
843 | Save all session configurations (default). | |
844 | .TP | |
845 | .BR "\-o, \-\-output-path PATH" | |
553067af DG |
846 | Specify the output path for saved sessions. This overrides the default session |
847 | configuration directory. | |
516f6cbe JG |
848 | .TP |
849 | .BR "\-f, -\-force" | |
850 | Overwrite session configuration file if session name clashes. | |
851 | .RE | |
852 | .PP | |
853 | ||
7c96a096 MD |
854 | .PP |
855 | \fBset-session\fP NAME [OPTIONS] | |
856 | .RS | |
6991b181 DG |
857 | Set current session name |
858 | ||
859 | Will change the session name in the .lttngrc file. | |
6991b181 DG |
860 | |
861 | .B OPTIONS: | |
862 | ||
7c96a096 MD |
863 | .TP |
864 | .BR "\-h, \-\-help" | |
865 | Show summary of possible options and commands. | |
866 | .TP | |
867 | .BR "\-\-list-options" | |
868 | Simple listing of options | |
869 | .RE | |
870 | .PP | |
6991b181 | 871 | |
8df3bfe9 MD |
872 | .PP |
873 | \fBsnapshot\fP [OPTIONS] ACTION | |
874 | .RS | |
b872baea | 875 | Snapshot command for LTTng session. |
b872baea DG |
876 | |
877 | .B OPTIONS: | |
878 | ||
8df3bfe9 MD |
879 | .TP |
880 | .BR "\-h, \-\-help" | |
881 | Show summary of possible options and commands. | |
882 | .TP | |
883 | .BR "\-\-list-options" | |
884 | Simple listing of options | |
b872baea | 885 | |
8df3bfe9 | 886 | .PP |
b872baea DG |
887 | .B ACTION: |
888 | ||
8df3bfe9 | 889 | .TP |
b872baea DG |
890 | \fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL> |
891 | ||
892 | Setup and add an snapshot output for a session. Output are the destination | |
893 | where the snapshot will be sent. Only one output is permitted. To change it, | |
894 | you'll need to delete it and add back the new one. | |
895 | ||
8df3bfe9 | 896 | .TP |
b872baea DG |
897 | \fBdel-output\fP ID | NAME [-s <NAME>] |
898 | ||
899 | Delete an output for a session using the ID. You can either specify the | |
900 | output's ID that can be found with list-output or the name. | |
901 | ||
8df3bfe9 | 902 | .TP |
b872baea DG |
903 | \fBlist-output\fP [-s <NAME>] |
904 | ||
905 | List the output of a session. Attributes of the output are printed. | |
906 | ||
8df3bfe9 | 907 | .TP |
b872baea DG |
908 | \fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>] |
909 | ||
910 | Snapshot a session's buffer(s) for all domains. If an URL is specified, it is | |
911 | used instead of a previously added output. Specifying only a name or/and a max | |
912 | size will override the current output values. For instance, you can record a | |
913 | snapshot with a custom maximum size or with a different name. | |
914 | ||
8df3bfe9 | 915 | .nf |
1ac1098f | 916 | $ lttng snapshot add-output -n mysnapshot file:///data/snapshot |
b872baea DG |
917 | [...] |
918 | $ lttng snapshot record -n new_name_snapshot | |
8df3bfe9 | 919 | .fi |
b872baea DG |
920 | |
921 | The above will create a snapshot in /data/snapshot/new_name_snapshot* directory | |
922 | rather then in mysnapshot*/ | |
b872baea | 923 | |
8df3bfe9 MD |
924 | .PP |
925 | .B DETAILED ACTION OPTIONS | |
b872baea | 926 | |
8df3bfe9 MD |
927 | .TP |
928 | .BR "\-s, \-\-session NAME" | |
929 | Apply to session name. | |
930 | .TP | |
931 | .BR "\-n, \-\-name NAME" | |
932 | Name of the snapshot's output. | |
933 | .TP | |
934 | .BR "\-m, \-\-max-size SIZE" | |
eb82f91d | 935 | Maximum size in bytes of the snapshot. The maximum size does not include the |
a8f307d8 SM |
936 | metadata file. Human readable format is accepted: {+k,+M,+G}. For instance, |
937 | \-\-max-size 5M | |
68808f4e DG |
938 | |
939 | The minimum size of a snapshot is computed by multiplying the total amount of | |
940 | streams in the session by the largest subbuffer size. This is to ensure | |
941 | fairness between channels when extracting data. | |
8df3bfe9 MD |
942 | .TP |
943 | .BR "\-C, \-\-ctrl-url URL" | |
944 | Set control path URL. (Must use -D also) | |
945 | .TP | |
946 | .BR "\-D, \-\-data-url URL" | |
947 | Set data path URL. (Must use -C also) | |
948 | .RE | |
949 | .PP | |
b872baea | 950 | |
afb8ca1b MD |
951 | .PP |
952 | \fBstart\fP [NAME] [OPTIONS] | |
953 | .RS | |
6991b181 DG |
954 | Start tracing |
955 | ||
956 | It will start tracing for all tracers for a specific tracing session. | |
6991b181 | 957 | If NAME is omitted, the session name is taken from the .lttngrc file. |
6991b181 DG |
958 | |
959 | .B OPTIONS: | |
960 | ||
afb8ca1b MD |
961 | .TP |
962 | .BR "\-h, \-\-help" | |
963 | Show summary of possible options and commands. | |
964 | .TP | |
965 | .BR "\-\-list-options" | |
966 | Simple listing of options | |
967 | .RE | |
968 | .PP | |
6991b181 | 969 | |
6c09bfdb MD |
970 | .PP |
971 | \fBstop\fP [NAME] [OPTIONS] | |
972 | .RS | |
6991b181 DG |
973 | Stop tracing |
974 | ||
391b9c72 DG |
975 | It will stop tracing for all tracers for a specific tracing session. Before |
976 | returning, the command checks for data availability meaning that it will wait | |
977 | until the trace is readable for the session. Use \-\-no-wait to avoid this | |
978 | behavior. | |
6991b181 DG |
979 | |
980 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
981 | |
982 | .B OPTIONS: | |
983 | ||
6c09bfdb MD |
984 | .TP |
985 | .BR "\-h, \-\-help" | |
986 | Show summary of possible options and commands. | |
987 | .TP | |
988 | .BR "\-\-list-options" | |
989 | Simple listing of options | |
3a7a166e MJ |
990 | .TP |
991 | .BR "\-\-no-wait" | |
6c09bfdb MD |
992 | Don't wait for data availability. |
993 | .RE | |
994 | .PP | |
6991b181 | 995 | |
5975c30a MD |
996 | .PP |
997 | \fBversion\fP | |
998 | .RS | |
6991b181 | 999 | Show version information |
6991b181 DG |
1000 | |
1001 | .B OPTIONS: | |
1002 | ||
5975c30a MD |
1003 | .TP |
1004 | .BR "\-h, \-\-help" | |
1005 | Show summary of possible options and commands. | |
1006 | .TP | |
1007 | .BR "\-\-list-options" | |
1008 | Simple listing of options | |
1009 | .RE | |
1010 | .PP | |
6991b181 | 1011 | |
5b4c1410 MD |
1012 | .PP |
1013 | \fBview\fP [SESSION_NAME] [OPTIONS] | |
1014 | .RS | |
1015 | View traces of a tracing session. By default, the babeltrace viewer | |
1016 | will be used for text viewing. If SESSION_NAME is omitted, the session | |
1017 | name is taken from the .lttngrc file. | |
6991b181 DG |
1018 | |
1019 | .B OPTIONS: | |
1020 | ||
5b4c1410 MD |
1021 | .TP |
1022 | .BR "\-h, \-\-help" | |
1023 | Show this help | |
1024 | .TP | |
1025 | .BR "\-\-list-options" | |
1026 | Simple listing of options | |
1027 | .TP | |
1028 | .BR "\-t, \-\-trace-path PATH" | |
1029 | Trace directory path for the viewer | |
1030 | .TP | |
1031 | .BR "\-e, \-\-viewer CMD" | |
1032 | Specify viewer and/or options to use This will completely override the | |
1033 | default viewers so please make sure to specify the full command. The | |
1034 | trace directory path of the session will be appended at the end to the | |
1035 | arguments | |
1036 | .RE | |
1037 | .PP | |
6991b181 | 1038 | |
999ee001 DG |
1039 | .SH "JUL/LOG4J DOMAIN" |
1040 | ||
1041 | This section explains the JUL and LOG4J domain where JUL stands for Java Util | |
1042 | Logging. You can use these by using the \fBliblttng-ust-<domain>-jni.so\fP from | |
1043 | the lttng-ust(3) project. | |
acf47627 DG |
1044 | |
1045 | The LTTng Java Agent uses JNI to link the UST tracer to the Java application | |
1046 | that uses the agent. Thus, it behaves similarly to the UST domain (\-u). When | |
999ee001 DG |
1047 | enabling events, you enable a Logger name that will then be mapped to a default |
1048 | UST tracepoint called \fBlttng_jul:<domain>_event\fP in the | |
1049 | \fBlttng_<domain>_channel\fP. Using the lttng-ctl API, any JUL/LOG4J events | |
1050 | must use the tracepoint event type (same as \-\-tracepoint). | |
acf47627 | 1051 | |
999ee001 DG |
1052 | Because of the default immutable channel, the \fBenable-channel\fP command CAN |
1053 | NOT be used with the JUL and LOG4J domain thus not having any options. | |
acf47627 | 1054 | |
999ee001 DG |
1055 | Also, loglevels are supported. Use \fBlttng enable-event \-h\fP to list them. |
1056 | Wildcards are NOT supported except the "*" meaning all events (same as \-a). | |
acf47627 DG |
1057 | |
1058 | Exactly like the UST domain, if the Java application has the same UID as you, | |
1059 | you can trace it. Same goes for the tracing group accessing root applications. | |
1060 | ||
999ee001 DG |
1061 | Finally, you can list every Logger name that are available from registered |
1062 | applications to the session daemon by using \fBlttng list \-j\fP or \fB\-l\fP. | |
acf47627 | 1063 | |
999ee001 | 1064 | Here is an example on how to use the JUL domain. |
acf47627 DG |
1065 | |
1066 | .nf | |
1067 | $ lttng list -j | |
1068 | [...] | |
1069 | $ lttng create aSession | |
1070 | $ lttng enable-event -s aSession -j MyCustomLoggerName | |
1071 | $ lttng start | |
1072 | .fi | |
1073 | ||
1074 | More information can be found in the lttng-ust documentation, see | |
1075 | java-util-logging.txt | |
1076 | .PP | |
1077 | ||
c206d957 | 1078 | .SH "EXIT VALUES" |
b107a0b1 | 1079 | .PP |
6b8f2e64 DG |
1080 | On success 0 is returned and a positive value on error. Value of 1 means a command |
1081 | error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that | |
1082 | something went wrong during the command. | |
c206d957 | 1083 | |
6b8f2e64 | 1084 | Any other value above 10, please refer to |
b107a0b1 | 1085 | .BR "<lttng/lttng-error.h>" |
6b8f2e64 DG |
1086 | for a detailed list or use lttng_strerror() to get a human readable string of |
1087 | the error code. | |
c206d957 | 1088 | .PP |
b107a0b1 | 1089 | |
6991b181 DG |
1090 | .SH "ENVIRONMENT VARIABLES" |
1091 | ||
1092 | .PP | |
1093 | Note that all command line options override environment variables. | |
1094 | .PP | |
1095 | ||
1096 | .PP | |
05833633 | 1097 | .IP "LTTNG_SESSIOND_PATH" |
c9e32613 DG |
1098 | Allows one to specify the full session daemon binary path to lttng command line |
1099 | tool. You can also use \-\-sessiond-path option having the same effect. | |
b107a0b1 MD |
1100 | .PP |
1101 | ||
516f6cbe JG |
1102 | .PP |
1103 | .IP "LTTNG_SESSION_CONFIG_XSD_PATH" | |
1104 | Set the path in which the \fBsession.xsd\fP session configuration schema may be | |
1105 | found. | |
1106 | .PP | |
1107 | ||
6991b181 | 1108 | .SH "SEE ALSO" |
6b8f2e64 DG |
1109 | .BR babeltrace(1), |
1110 | .BR lttng-ust(3), | |
1111 | .BR lttng-sessiond(8), | |
1112 | .BR lttng-relayd(8), | |
b107a0b1 | 1113 | |
6991b181 DG |
1114 | .SH "BUGS" |
1115 | ||
b107a0b1 | 1116 | .PP |
6991b181 | 1117 | If you encounter any issues or usability problem, please report it on our |
6b8f2e64 | 1118 | mailing list <lttng-dev@lists.lttng.org> to help improve this project or |
eb82f91d | 1119 | at https://bugs.lttng.org which is a bug tracker. |
b107a0b1 MD |
1120 | .PP |
1121 | ||
6991b181 DG |
1122 | .SH "CREDITS" |
1123 | ||
1124 | .PP | |
c9e32613 | 1125 | lttng is distributed under the GNU General Public License version 2. See the file |
6991b181 DG |
1126 | COPYING for details. |
1127 | .PP | |
1128 | A Web site is available at http://lttng.org for more information on the LTTng | |
1129 | project. | |
1130 | .PP | |
1131 | You can also find our git tree at http://git.lttng.org. | |
1132 | .PP | |
1133 | Mailing lists for support and development: <lttng-dev@lists.lttng.org>. | |
1134 | .PP | |
1135 | You can find us on IRC server irc.oftc.net (OFTC) in #lttng. | |
1136 | .PP | |
1137 | .SH "THANKS" | |
1138 | ||
1139 | .PP | |
1140 | Thanks to Yannick Brosseau without whom this project would never have been so | |
1141 | lean and mean! Also thanks to the Ericsson teams working on tracing which | |
fa072eae | 1142 | helped us greatly with detailed bug reports and unusual test cases. |
6991b181 DG |
1143 | |
1144 | Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA | |
1145 | maintainer) and Jon Bernard for our Debian packages. | |
1146 | ||
1147 | Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de | |
1148 | Montreal for the LTTng journey. | |
c9e32613 | 1149 | .PP |
6991b181 DG |
1150 | .SH "AUTHORS" |
1151 | ||
1152 | .PP | |
1153 | lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and | |
1154 | David Goulet. More people have since contributed to it. It is currently | |
9b22d135 | 1155 | maintained by Jérémie Galarneau <jeremie.galarneau@efficios.com>. |
6991b181 | 1156 | .PP |