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516f6cbe | 1 | .TH "LTTNG" "1" "May 13th, 2014" "" "" |
6991b181 DG |
2 | |
3 | .SH "NAME" | |
94ffb05d | 4 | lttng \- 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 | |
c0fdca17 | 51 | This program follows the usual GNU command line syntax with long options starting with |
6991b181 DG |
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 | |
c0fdca17 JG |
59 | .BR "\-V, \-\-version" |
60 | Show version. | |
61 | .TP | |
c9e32613 | 62 | .BR "\-v, \-\-verbose" |
6991b181 | 63 | Increase verbosity. |
d829b38c | 64 | Three levels of verbosity are available which are triggered by putting additional v to |
fa072eae | 65 | the option (\-vv or \-vvv) |
6991b181 | 66 | .TP |
c9e32613 | 67 | .BR "\-q, \-\-quiet" |
6991b181 DG |
68 | Suppress all messages (even errors). |
69 | .TP | |
c9e32613 | 70 | .BR "\-g, \-\-group NAME" |
6991b181 DG |
71 | Set unix tracing group name. (default: tracing) |
72 | .TP | |
c9e32613 | 73 | .BR "\-n, \-\-no-sessiond" |
6991b181 DG |
74 | Don't automatically spawn a session daemon. |
75 | .TP | |
391b9c72 | 76 | .BR "\-\-sessiond\-path PATH" |
6991b181 DG |
77 | Set session daemon full binary path. |
78 | .TP | |
c9e32613 | 79 | .BR "\-\-list\-options" |
6991b181 DG |
80 | Simple listing of lttng options. |
81 | .TP | |
c9e32613 | 82 | .BR "\-\-list\-commands" |
6991b181 | 83 | Simple listing of lttng commands. |
ed43168a JRJ |
84 | .TP |
85 | .BR "\-m, \-\-mi TYPE | |
86 | Machine interface | |
87 | ||
88 | TYPE supported: XML | |
89 | ||
90 | Machine interface (MI) mode converts the traditional pretty printing to a | |
91 | machine output syntax. MI mode provides a format change-resistant way to access | |
92 | information generated via the lttng command line. | |
93 | ||
94 | When using MI mode, the data is printed on \fBstdout\fP. Error and warning are | |
95 | printed on \fBstderr\fP with the pretty print default format. | |
96 | ||
97 | If any errors occur during the execution of a command, the return value of the | |
98 | command will be different than zero. In this case, lttng does NOT guarantee the | |
99 | syntax and data validity of the generated MI output. | |
100 | ||
101 | For XML output type, a schema definition (XSD) file used for validation can be | |
102 | found under src/common/mi_lttng.xsd | |
103 | ||
6991b181 DG |
104 | .SH "COMMANDS" |
105 | ||
812a5eb7 | 106 | .PP |
ee2758e5 | 107 | \fBadd-context\fP [OPTIONS] |
812a5eb7 | 108 | .RS |
6991b181 DG |
109 | Add context to event(s) and/or channel(s). |
110 | ||
391b9c72 DG |
111 | A context is basically extra information appended to a channel. For instance, |
112 | you could ask the tracer to add the PID information for all events in a | |
113 | channel. You can also add performance monitoring unit counters (perf PMU) using | |
aa3514e9 | 114 | the perf kernel API. |
6991b181 | 115 | |
aa3514e9 MD |
116 | For example, this command will add the context information 'prio' and two per-CPU |
117 | perf counters (hardware branch misses and cache misses), to all events in the trace | |
6991b181 DG |
118 | data output: |
119 | ||
812a5eb7 | 120 | .nf |
aa3514e9 MD |
121 | # lttng add-context \-k \-t prio \-t perf:cpu:branch-misses \\ |
122 | \-t perf:cpu:cache-misses | |
812a5eb7 | 123 | .fi |
6991b181 | 124 | |
c9e32613 | 125 | Please take a look at the help (\-h/\-\-help) for a detailed list of available |
6991b181 DG |
126 | contexts. |
127 | ||
aa3514e9 MD |
128 | Perf counters are available as per-CPU ("perf:cpu:...") and per-thread |
129 | ("perf:thread:...") counters. Currently, per-CPU counters can only be | |
130 | used with the kernel tracing domain, and per-thread counters can only be | |
131 | used with the UST tracing domain. | |
132 | ||
bd337b98 DG |
133 | If no channel is given (\-c), the context is added to all channels that were |
134 | already enabled. If the session has no channel, a default channel is created. | |
31ea4846 | 135 | Otherwise the context will be added only to the given channel (\-c). |
6991b181 | 136 | |
c9e32613 | 137 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 138 | file. |
6991b181 DG |
139 | |
140 | .B OPTIONS: | |
141 | ||
812a5eb7 MD |
142 | .TP |
143 | .BR "\-h, \-\-help" | |
144 | Show summary of possible options and commands. | |
145 | .TP | |
146 | .BR "\-s, \-\-session NAME" | |
147 | Apply on session name. | |
148 | .TP | |
149 | .BR "\-c, \-\-channel NAME" | |
150 | Apply on channel name. | |
151 | .TP | |
152 | .BR "\-k, \-\-kernel" | |
153 | Apply for the kernel tracer | |
154 | .TP | |
155 | .BR "\-u, \-\-userspace" | |
156 | Apply for the user-space tracer | |
157 | .TP | |
158 | .BR "\-t, \-\-type TYPE" | |
159 | Context type. You can repeat this option on the command line. Please | |
160 | use "lttng add-context \-h" to list all available types. | |
161 | .RE | |
162 | .PP | |
6991b181 | 163 | |
22019883 MD |
164 | .PP |
165 | \fBcalibrate\fP [OPTIONS] | |
166 | .RS | |
6991b181 DG |
167 | Quantify LTTng overhead |
168 | ||
169 | The LTTng calibrate command can be used to find out the combined average | |
170 | overhead of the LTTng tracer and the instrumentation mechanisms used. This | |
171 | overhead can be calibrated in terms of time or using any of the PMU performance | |
172 | counter available on the system. | |
173 | ||
174 | For now, the only calibration implemented is that of the kernel function | |
175 | instrumentation (kretprobes). | |
176 | ||
177 | * Calibrate kernel function instrumentation | |
178 | ||
179 | Let's use an example to show this calibration. We use an i7 processor with 4 | |
180 | general-purpose PMU registers. This information is available by issuing dmesg, | |
181 | looking for "generic registers". | |
182 | ||
183 | This sequence of commands will gather a trace executing a kretprobe hooked on | |
184 | an empty function, gathering PMU counters LLC (Last Level Cache) misses | |
c9e32613 | 185 | information (see lttng add-context \-\-help to see the list of available PMU |
6991b181 DG |
186 | counters). |
187 | ||
22019883 | 188 | .nf |
6991b181 | 189 | # lttng create calibrate-function |
22019883 MD |
190 | # lttng enable-event calibrate \-\-kernel \\ |
191 | \-\-function lttng_calibrate_kretprobe | |
aa3514e9 MD |
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 | |
6991b181 DG |
195 | # lttng start |
196 | # for a in $(seq 1 10); do \\ | |
c9e32613 | 197 | lttng calibrate \-\-kernel \-\-function; |
6991b181 DG |
198 | done |
199 | # lttng destroy | |
22019883 MD |
200 | # babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\ |
201 | | tail \-n 1) | |
202 | .fi | |
6991b181 DG |
203 | |
204 | The output from babeltrace can be saved to a text file and opened in a | |
205 | spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between | |
206 | consecutive "calibrate_entry" and "calibrate_return" events. Note that these | |
207 | counters are per-CPU, so scheduling events would need to be present to account | |
208 | for migration between CPU. Therefore, for calibration purposes, only events | |
209 | staying on the same CPU must be considered. | |
210 | ||
211 | The average result, for the i7, on 10 samples: | |
212 | ||
22019883 | 213 | .nf |
6991b181 DG |
214 | Average Std.Dev. |
215 | perf_LLC_load_misses: 5.0 0.577 | |
216 | perf_LLC_store_misses: 1.6 0.516 | |
217 | perf_LLC_prefetch_misses: 9.0 14.742 | |
22019883 | 218 | .fi |
6991b181 DG |
219 | |
220 | As 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. | |
222 | We can conclude from this information that LLC load and store misses can be | |
223 | accounted for quite precisely, but prefetches within a function seems to behave | |
224 | too erratically (not much causality link between the code executed and the CPU | |
225 | prefetch activity) to be accounted for. | |
6991b181 DG |
226 | |
227 | .B OPTIONS: | |
228 | ||
22019883 MD |
229 | .TP |
230 | .BR "\-h, \-\-help" | |
231 | Show summary of possible options and commands. | |
232 | .TP | |
233 | .BR "\-k, \-\-kernel" | |
234 | Apply for the kernel tracer | |
235 | .TP | |
236 | .BR "\-u, \-\-userspace" | |
237 | Apply for the user-space tracer | |
238 | .TP | |
239 | .BR "\-\-function" | |
240 | Dynamic function entry/return probe (default) | |
241 | .RE | |
242 | .PP | |
6991b181 | 243 | |
ee2758e5 | 244 | .PP |
feb3ca56 | 245 | \fBcreate\fP [NAME] [OPTIONS] |
ee2758e5 | 246 | .RS |
6991b181 DG |
247 | Create tracing session. |
248 | ||
249 | A tracing session contains channel(s) which contains event(s). It is domain | |
e256d661 | 250 | agnostic, meaning that channels and events can be enabled for the |
6991b181 DG |
251 | user-space tracer and/or the kernel tracer. It acts like a container |
252 | aggregating multiple tracing sources. | |
253 | ||
254 | On creation, a \fB.lttngrc\fP file is created in your $HOME directory | |
255 | containing the current session name. If NAME is omitted, a session name is | |
fa072eae | 256 | automatically created having this form: 'auto-yyyymmdd-hhmmss'. |
6991b181 | 257 | |
c9e32613 | 258 | If no \fB\-o, \-\-output\fP is specified, the traces will be written in |
6991b181 | 259 | $HOME/lttng-traces. |
feb0f3e5 AM |
260 | |
261 | The $HOME environment variable can be overridden by defining the environment | |
262 | variable LTTNG_HOME. This is useful when the user running the commands has | |
263 | a non-writeable home directory. | |
6991b181 | 264 | |
1c1c3634 DG |
265 | The session name MUST NOT contain the character '/'. |
266 | ||
6991b181 DG |
267 | .B OPTIONS: |
268 | ||
ee2758e5 MD |
269 | .TP |
270 | .BR "\-h, \-\-help" | |
271 | Show summary of possible options and commands. | |
272 | .TP | |
273 | .BR "\-\-list-options" | |
274 | Simple listing of options | |
275 | .TP | |
276 | .BR "\-o, \-\-output PATH" | |
277 | Specify output path for traces | |
278 | .TP | |
96fe6b8d DG |
279 | .BR "\-\-no-output" |
280 | Traces will not be output | |
281 | .TP | |
ee2758e5 | 282 | .BR "\-\-snapshot" |
96fe6b8d DG |
283 | Set the session in snapshot mode. Created in no-output mode and uses the |
284 | URL, if one is specified, as the default snapshot output. Every channel will be set | |
ee2758e5 | 285 | in overwrite mode and with mmap output (splice not supported). |
0794f51b | 286 | .TP |
d73c5802 | 287 | .BR "\-\-live [USEC]" |
eb82f91d | 288 | Set the session exclusively in live mode. The parameter is the delay in micro |
0794f51b DG |
289 | seconds before the data is flushed and streamed. The live mode allows you to |
290 | stream the trace and view it while it's being recorded by any tracer. For that, | |
291 | you need a lttng-relayd and this session requires a network URL (\-U or | |
d73c5802 DG |
292 | \-C/\-D). If no USEC nor URL is provided, the default is to use a timer value |
293 | set to 1000000 and the network URL set to net://127.0.0.1. | |
0794f51b DG |
294 | |
295 | To read a live session, you can use babeltrace(1) or the live streaming | |
296 | protocol 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 | ||
305 | After the start, you'll be able to read the events while they are being | |
306 | recorded in /tmp/lttng. | |
6b8f2e64 | 307 | |
d7ba1388 MD |
308 | .TP |
309 | .BR "\-\-shm-path PATH" | |
310 | ||
311 | Path where shared memory holding buffers should be created. Useful | |
6a9a8e6a JG |
312 | when used with PRAMFS or other persistent memory filesystems to extract |
313 | trace data in the event of a crash requiring a reboot. | |
d7ba1388 | 314 | |
464bd4b0 JR |
315 | See the \fBlttng-crash(1)\fP utility for more information on crash recovery. |
316 | ||
ee2758e5 MD |
317 | .TP |
318 | .BR "\-U, \-\-set-url=URL" | |
319 | Set URL for the consumer output destination. It is persistent for the | |
320 | session lifetime. Redo the command to change it. This will set both data | |
321 | and control URL for network. | |
322 | .TP | |
323 | .BR "\-C, \-\-ctrl-url=URL" | |
324 | Set control path URL. (Must use -D also) | |
325 | .TP | |
326 | .BR "\-D, \-\-data-url=URL" | |
327 | Set data path URL. (Must use -C also) | |
328 | .PP | |
6b8f2e64 DG |
329 | Using these options, each API call can be controlled individually. For |
330 | instance, \-C does not enable the consumer automatically. You'll need the \-e | |
331 | option for that. | |
332 | ||
785d2d0d DG |
333 | .B URL FORMAT: |
334 | ||
335 | proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH] | |
336 | ||
337 | Supported protocols are (proto): | |
ee2758e5 MD |
338 | .TP |
339 | .BR "file://..." | |
340 | Local filesystem full path. | |
785d2d0d | 341 | |
ee2758e5 MD |
342 | .TP |
343 | .BR "net://..." | |
344 | This will use the default network transport layer which is TCP for both | |
345 | control (PORT1) and data port (PORT2). The default ports are | |
346 | respectively 5342 and 5343. Note that net[6]:// is not yet supported. | |
785d2d0d | 347 | |
ee2758e5 MD |
348 | .TP |
349 | .BR "tcp[6]://..." | |
350 | Can only be used with -C and -D together | |
785d2d0d DG |
351 | |
352 | NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732) | |
6b8f2e64 DG |
353 | |
354 | .B EXAMPLES: | |
355 | ||
ee2758e5 | 356 | .nf |
6b8f2e64 | 357 | # lttng create -U net://192.168.1.42 |
ee2758e5 | 358 | .fi |
6b8f2e64 DG |
359 | Uses TCP and default ports for the given destination. |
360 | ||
ee2758e5 | 361 | .nf |
6b8f2e64 | 362 | # lttng create -U net6://[fe80::f66d:4ff:fe53:d220] |
ee2758e5 | 363 | .fi |
6b8f2e64 DG |
364 | Uses TCP, default ports and IPv6. |
365 | ||
ee2758e5 | 366 | .nf |
6b8f2e64 | 367 | # lttng create s1 -U net://myhost.com:3229 |
6991b181 | 368 | .fi |
ee2758e5 MD |
369 | Create session s1 and set its consumer to myhost.com on port 3229 for control. |
370 | .RE | |
371 | .PP | |
6991b181 | 372 | |
f2b14ef1 MD |
373 | .PP |
374 | \fBdestroy\fP [NAME] [OPTIONS] | |
375 | .RS | |
6991b181 DG |
376 | Teardown tracing session |
377 | ||
378 | Free memory on the session daemon and tracer side. It's gone! | |
379 | ||
380 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
381 | |
382 | .B OPTIONS: | |
383 | ||
f2b14ef1 MD |
384 | .TP |
385 | .BR "\-h, \-\-help" | |
386 | Show summary of possible options and commands. | |
387 | .TP | |
388 | .BR "\-a, \-\-all" | |
389 | Destroy all sessions | |
390 | .TP | |
391 | .BR "\-\-list-options" | |
392 | Simple listing of options | |
393 | .RE | |
394 | .PP | |
6991b181 | 395 | |
05be3802 MD |
396 | .PP |
397 | \fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
398 | .RS | |
6991b181 DG |
399 | Enable tracing channel |
400 | ||
004f3466 DG |
401 | To enable an event, you must enable both the event and the channel that |
402 | contains it. | |
b883c01b | 403 | |
c9e32613 | 404 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 405 | file. |
7972aab2 | 406 | |
05be3802 MD |
407 | Exactly one of \-k or -u must be specified. |
408 | ||
7972aab2 | 409 | It is important to note that if a certain type of buffers is used, the session |
bd337b98 | 410 | will be set with that type and all other subsequent channel needs to have the |
7972aab2 | 411 | same type. |
bd337b98 | 412 | |
d2f11c4a DG |
413 | Note that once the session has been started and enabled on the tracer side, |
414 | it's not possible anymore to enable a new channel for that session. | |
6991b181 DG |
415 | |
416 | .B OPTIONS: | |
417 | ||
05be3802 MD |
418 | .TP |
419 | .BR "\-h, \-\-help" | |
420 | Show this help | |
421 | .TP | |
422 | .BR "\-\-list-options" | |
423 | Simple listing of options | |
424 | .TP | |
425 | .BR "\-s, \-\-session NAME" | |
426 | Apply on session name | |
427 | .TP | |
428 | .BR "\-k, \-\-kernel" | |
429 | Apply to the kernel tracer | |
430 | .TP | |
431 | .BR "\-u, \-\-userspace" | |
432 | Apply to the user-space tracer | |
433 | .TP | |
434 | .BR "\-\-discard" | |
435 | Discard event when subbuffers are full (default) | |
436 | .TP | |
437 | .BR "\-\-overwrite" | |
33fbd469 DG |
438 | Flight recorder mode: overwrites events when subbuffers are full. The |
439 | number of subbuffer must be 2 or more. | |
05be3802 MD |
440 | .TP |
441 | .BR "\-\-subbuf-size SIZE" | |
442 | Subbuffer size in bytes {+k,+M,+G}. | |
443 | (default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096) | |
444 | Rounded up to the next power of 2. | |
445 | ||
446 | The minimum subbuffer size, for each tracer, is the max value between | |
447 | the default above and the system page size. You can issue this command | |
448 | to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP | |
449 | .TP | |
450 | .BR "\-\-num-subbuf NUM" | |
451 | Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4, | |
452 | metadata: 2) Rounded up to the next power of 2. | |
453 | .TP | |
454 | .BR "\-\-switch-timer USEC" | |
455 | Switch subbuffer timer interval in µsec. | |
456 | (default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0) | |
457 | .TP | |
458 | .BR "\-\-read-timer USEC" | |
459 | Read timer interval in µsec. | |
460 | (default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0) | |
461 | .TP | |
462 | .BR "\-\-output TYPE" | |
463 | Channel output type. Possible values: mmap, splice | |
464 | (default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap) | |
465 | .TP | |
466 | .BR "\-\-buffers-uid" | |
467 | Use per UID buffer (\-u only). Buffers are shared between applications | |
468 | that have the same UID. | |
469 | .TP | |
470 | .BR "\-\-buffers-pid" | |
471 | Use per PID buffer (\-u only). Each application has its own buffers. | |
472 | .TP | |
473 | .BR "\-\-buffers-global" | |
474 | Use shared buffer for the whole system (\-k only) | |
475 | .TP | |
476 | .BR "\-C, \-\-tracefile-size SIZE" | |
477 | Maximum size of each tracefile within a stream (in bytes). | |
478 | 0 means unlimited. (default: 0) | |
c0684a0d | 479 | Note: traces generated with this option may inaccurately report |
a10f04ad | 480 | discarded events as of CTF 1.8. |
05be3802 MD |
481 | .TP |
482 | .BR "\-W, \-\-tracefile-count COUNT" | |
483 | Used in conjunction with \-C option, this will limit the number of files | |
484 | created to the specified count. 0 means unlimited. (default: 0) | |
1624d5b7 JD |
485 | |
486 | .B EXAMPLES: | |
487 | ||
05be3802 MD |
488 | .nf |
489 | $ lttng enable-channel -k -C 4096 -W 32 chan1 | |
490 | .fi | |
e256d661 | 491 | For each stream, the maximum size of each trace file will be 4096 bytes and |
cea28771 | 492 | there will be a maximum of 32 different files. The file count is appended after |
1624d5b7 JD |
493 | the stream number as seen in the following example. The last trace file is |
494 | smaller than 4096 since it was not completely filled. | |
495 | ||
05be3802 | 496 | .nf |
1624d5b7 JD |
497 | ~/lttng-traces/[...]/chan1_0_0 (4096) |
498 | ~/lttng-traces/[...]/chan1_0_1 (4096) | |
499 | ~/lttng-traces/[...]/chan1_0_2 (3245) | |
500 | ~/lttng-traces/[...]/chan1_1_0 (4096) | |
501 | ... | |
05be3802 | 502 | .fi |
1624d5b7 | 503 | |
05be3802 MD |
504 | .nf |
505 | $ lttng enable-channel -k -C 4096 | |
506 | .fi | |
1624d5b7 JD |
507 | This will create trace files of 4096 bytes and will create new ones as long as |
508 | there is data available. | |
05be3802 MD |
509 | .RE |
510 | .PP | |
6991b181 | 511 | |
6a240cd9 | 512 | .PP |
fe4b07c7 | 513 | \fBenable-event\fP NAME[,NAME2,...] (\-k | \-u | \-j | \-l | \-p) [OPTIONS] |
6a240cd9 | 514 | .RS |
6991b181 DG |
515 | Enable tracing event |
516 | ||
c9e32613 | 517 | A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is |
6991b181 | 518 | omitted, a default channel named '\fBchannel0\fP' is created and the event is |
85076754 MD |
519 | added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default |
520 | channel already exists within the session, an error is returned. For the | |
521 | user-space tracer, using \fB\-a, \-\-all\fP is the same as using the | |
522 | wildcard "*". | |
6991b181 | 523 | |
c9e32613 | 524 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 525 | file. |
6991b181 DG |
526 | |
527 | .B OPTIONS: | |
528 | ||
6a240cd9 MD |
529 | .TP |
530 | .BR "\-h, \-\-help" | |
531 | Show summary of possible options and commands. | |
532 | .TP | |
533 | .BR "\-\-list-options" | |
534 | Simple listing of options | |
535 | .TP | |
536 | .BR "\-s, \-\-session NAME" | |
537 | Apply on session name | |
538 | .TP | |
539 | .BR "\-c, \-\-channel NAME" | |
540 | Apply on channel name | |
541 | .TP | |
542 | .BR "\-a, \-\-all" | |
e256d661 | 543 | Enable all tracepoints and syscalls. This actually enables a single |
6a240cd9 MD |
544 | wildcard event "*". |
545 | .TP | |
546 | .BR "\-k, \-\-kernel" | |
547 | Apply for the kernel tracer | |
548 | .TP | |
549 | .BR "\-u, \-\-userspace" | |
550 | Apply for the user-space tracer | |
551 | .TP | |
bed69e7d DG |
552 | .BR "\-j, \-\-jul" |
553 | Apply for Java application using Java Util Logging interface (JUL) | |
554 | .TP | |
222e4eab DG |
555 | .BR "\-l, \-\-log4j" |
556 | Apply for Java application using LOG4J | |
557 | .TP | |
0e115563 DG |
558 | .BR "\-p, \-\-python" |
559 | Apply for Python application using the logging module. | |
560 | .TP | |
6a240cd9 | 561 | .BR "\-\-tracepoint" |
e256d661 | 562 | Tracepoint event (default). Userspace tracer supports wildcards at the end |
6a240cd9 MD |
563 | of string. Don't forget to quote to deal with bash expansion. |
564 | e.g.: | |
6991b181 | 565 | .nf |
6991b181 DG |
566 | "*" |
567 | "app_component:na*" | |
6991b181 | 568 | .fi |
6a240cd9 MD |
569 | .TP |
570 | .BR "\-\-loglevel NAME" | |
571 | Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h). | |
f9e8873b DG |
572 | For the JUL domain, the loglevel ranges are detailed with the \-\-help |
573 | option thus starting from SEVERE to FINEST. | |
999ee001 DG |
574 | For the LOG4J domain, loglevels range from FATAL to TRACE which are also |
575 | detailed in the help. | |
0e115563 DG |
576 | For the Python domain, loglevels range from CRITICAL to DEBUG which are |
577 | detailed in the help as well. | |
6a240cd9 MD |
578 | .TP |
579 | .BR "\-\-loglevel-only NAME" | |
580 | Tracepoint loglevel (only this loglevel). | |
581 | The loglevel or loglevel-only options should be combined with a | |
582 | tracepoint name or tracepoint wildcard. | |
583 | .TP | |
584 | .BR "\-\-probe (addr | symbol | symbol+offset)" | |
585 | Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...) | |
586 | or hexadecimal (0xNNN...) | |
587 | .TP | |
588 | .BR "\-\-function (addr | symbol | symbol+offset)" | |
589 | Dynamic function entry/return probe. Addr and offset can be octal | |
590 | (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...) | |
591 | .TP | |
592 | .BR "\-\-syscall" | |
68aa8ac7 | 593 | System call event. |
6a240cd9 MD |
594 | .TP |
595 | .BR "\-\-filter 'expression'" | |
596 | Set a filter on a newly enabled event. Filter expression on event | |
e256d661 JG |
597 | fields and context. The event will be recorded if the filter's |
598 | expression evaluates to TRUE. Only specify on first activation of a | |
599 | given event within a session. | |
600 | Specifying a filter is only allowed when enabling events within a session before | |
6a240cd9 MD |
601 | tracing is started. If the filter fails to link with the event |
602 | within the traced domain, the event will be discarded. | |
6a240cd9 MD |
603 | |
604 | Expression examples: | |
605 | ||
606 | .nf | |
607 | 'intfield > 500 && intfield < 503' | |
608 | '(strfield == "test" || intfield != 10) && intfield > 33' | |
609 | 'doublefield > 1.1 && intfield < 5.3' | |
10b56aef | 610 | 'enumfield == 1234' |
6a240cd9 MD |
611 | .fi |
612 | ||
613 | Wildcards are allowed at the end of strings: | |
614 | 'seqfield1 == "te*"' | |
615 | In string literals, the escape character is a '\\'. Use '\\*' for | |
e256d661 JG |
616 | the '*' character, and '\\\\' for the '\\' character sequence. Wildcard |
617 | matches any sequence of characters, including an empty sub-string | |
10b56aef MD |
618 | (matches 0 or more characters). Enumeration fields can currently only be |
619 | compared as integers. | |
6a240cd9 | 620 | |
e256d661 JG |
621 | Context information can be used for filtering. The examples below shows |
622 | usage of context filtering on the process name (using a wildcard), process ID | |
623 | range, and unique thread ID. The process and thread IDs of | |
6a240cd9 MD |
624 | running applications can be found under columns "PID" and "LWP" of the |
625 | "ps -eLf" command. | |
626 | ||
627 | .nf | |
628 | '$ctx.procname == "demo*"' | |
629 | '$ctx.vpid >= 4433 && $ctx.vpid < 4455' | |
630 | '$ctx.vtid == 1234' | |
631 | .fi | |
632 | ||
11139b74 DG |
633 | Context information is available to all filters whether or not the add-context |
634 | command has been used to add it to the event's channel, as long as the context | |
635 | field exists for that domain. For example, the filter examples given above will | |
636 | never fail to link: no add-context is required for the event's channel. | |
637 | ||
bccd20a3 JI |
638 | .TP |
639 | .BR "\-x, \-\-exclude LIST" | |
640 | Add exclusions to UST tracepoints: | |
641 | Events that match any of the items in the comma-separated LIST are not | |
642 | enabled, even if they match a wildcard definition of the event. | |
643 | ||
644 | This option is also applicable with the \fB\-a, \-\-all\fP option, | |
645 | in which case all UST tracepoints are enabled except the ones whose | |
646 | names match any of the items in LIST. | |
6a240cd9 MD |
647 | .RE |
648 | .PP | |
6991b181 | 649 | |
272c6a17 MD |
650 | .PP |
651 | \fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
652 | .RS | |
6991b181 DG |
653 | Disable tracing channel |
654 | ||
e256d661 | 655 | Disabling a channel disables the tracing of all of the channel's events. A channel |
5368d366 | 656 | can be re-enabled by calling \fBlttng enable-channel NAME\fP again. |
6991b181 | 657 | |
c9e32613 | 658 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 659 | file. |
6991b181 DG |
660 | |
661 | .B OPTIONS: | |
662 | ||
272c6a17 MD |
663 | .TP |
664 | .BR "\-h, \-\-help" | |
665 | Show summary of possible options and commands. | |
666 | .TP | |
667 | .BR "\-\-list-options" | |
668 | Simple listing of options | |
669 | .TP | |
670 | .BR "\-s, \-\-session NAME" | |
671 | Apply on session name | |
672 | .TP | |
673 | .BR "\-k, \-\-kernel" | |
674 | Apply for the kernel tracer | |
675 | .TP | |
676 | .BR "\-u, \-\-userspace" | |
677 | Apply for the user-space tracer | |
678 | .RE | |
679 | .PP | |
6991b181 | 680 | |
c138a39b | 681 | .PP |
68aa8ac7 | 682 | \fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u | \-j | \-l | \-p) [TYPE] [OPTIONS] |
c138a39b | 683 | .RS |
6991b181 DG |
684 | Disable tracing event |
685 | ||
686 | The event, once disabled, can be re-enabled by calling \fBlttng enable-event | |
687 | NAME\fP again. | |
688 | ||
c9e32613 | 689 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 690 | file. |
6991b181 | 691 | |
85076754 MD |
692 | If \fB\-c, \-\-channel\fP is omitted, the default channel name is used. |
693 | If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already | |
694 | exists within the session, an error is returned. | |
695 | ||
6991b181 DG |
696 | .B OPTIONS: |
697 | ||
c138a39b MD |
698 | .TP |
699 | .BR "\-h, \-\-help" | |
700 | Show summary of possible options and commands. | |
701 | .TP | |
702 | .BR "\-\-list-options" | |
703 | Simple listing of options | |
704 | .TP | |
705 | .BR "\-s, \-\-session NAME" | |
706 | Apply on session name | |
707 | .TP | |
85076754 MD |
708 | .BR "\-c, \-\-channel NAME" |
709 | Apply on channel name | |
710 | .TP | |
c138a39b | 711 | .BR "\-a, \-\-all-events" |
68aa8ac7 JR |
712 | Disable all events. This does NOT ONLY disable "*" but rather every known |
713 | events of the session | |
c138a39b MD |
714 | .TP |
715 | .BR "\-k, \-\-kernel" | |
716 | Apply for the kernel tracer | |
717 | .TP | |
718 | .BR "\-u, \-\-userspace" | |
719 | Apply for the user-space tracer | |
bed69e7d DG |
720 | .TP |
721 | .BR "\-j, \-\-jul" | |
722 | Apply for Java application using Java Util Logging interface (JUL) | |
222e4eab DG |
723 | .TP |
724 | .BR "\-l, \-\-log4j" | |
725 | Apply for Java application using LOG4J | |
0e115563 DG |
726 | .TP |
727 | .BR "\-p, \-\-python" | |
68aa8ac7 JR |
728 | Apply for Python application using the logging module |
729 | ||
730 | .TP | |
731 | .B TYPE (kernel domain only): | |
732 | ||
733 | .TP | |
734 | .BR "\-\-all" | |
735 | Disable event of all type | |
736 | .TP | |
737 | .BR "\-\-tracepoint" | |
738 | Disable event of type tracepoint | |
739 | .TP | |
740 | .BR "\-\-syscall" | |
741 | Disable event of type syscall | |
742 | .TP | |
743 | .BR "\-\-probe" | |
744 | Disable event of type probe | |
745 | .TP | |
746 | .BR "\-\-function" | |
747 | Disable event of type function | |
c138a39b MD |
748 | .RE |
749 | .PP | |
6991b181 | 750 | |
747361fe MD |
751 | .PP |
752 | \fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]] | |
753 | .RS | |
c9e32613 | 754 | List tracing session information. |
6991b181 DG |
755 | |
756 | With no arguments, it will list available tracing session(s). | |
757 | ||
fa072eae YB |
758 | With the session name, it will display the details of the session including |
759 | the trace file path, the associated channels and their state (activated | |
d829b38c | 760 | and deactivated), the activated events and more. |
fa072eae | 761 | |
c9e32613 | 762 | With \-k alone, it will list all available kernel events (except the system |
6991b181 | 763 | calls events). |
bed69e7d DG |
764 | With \-j alone, the available JUL event from registered application will be |
765 | list. The event corresponds to the Logger name in the Java JUL application. | |
999ee001 DG |
766 | With \-l alone, the available LOG4J event from registered application will be |
767 | list. The event corresponds to the Logger name in the Java LOG4J application. | |
0e115563 DG |
768 | With \-p alone, the available Python event from registered application will be |
769 | list. The event corresponds to the Logger name in the Python application. | |
c9e32613 DG |
770 | With \-u alone, it will list all available user-space events from registered |
771 | applications. Here is an example of 'lttng list \-u': | |
6991b181 | 772 | |
747361fe | 773 | .nf |
6991b181 DG |
774 | PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello |
775 | ust_tests_hello:tptest_sighandler (type: tracepoint) | |
776 | ust_tests_hello:tptest (type: tracepoint) | |
747361fe | 777 | .fi |
6991b181 DG |
778 | |
779 | You can now enable any event listed by using the name : | |
780 | \fBust_tests_hello:tptest\fP. | |
6991b181 DG |
781 | |
782 | .B OPTIONS: | |
783 | ||
747361fe MD |
784 | .TP |
785 | .BR "\-h, \-\-help" | |
786 | Show summary of possible options and commands. | |
787 | .TP | |
788 | .BR "\-\-list-options" | |
789 | Simple listing of options | |
790 | .TP | |
791 | .BR "\-k, \-\-kernel" | |
792 | Select kernel domain | |
793 | .TP | |
794 | .BR "\-u, \-\-userspace" | |
795 | Select user-space domain. | |
bed69e7d DG |
796 | .TP |
797 | .BR "\-j, \-\-jul" | |
798 | Apply for Java application using JUL | |
799 | .TP | |
222e4eab DG |
800 | .BR "\-l, \-\-log4j" |
801 | Apply for Java application using LOG4J | |
0e115563 DG |
802 | .TP |
803 | .BR "\-p, \-\-python" | |
804 | Apply for Python application using the logging module. | |
805 | .TP | |
bed69e7d DG |
806 | .BR "\-f, \-\-fields" |
807 | List event fields | |
6991b181 | 808 | |
747361fe | 809 | .PP |
6b8f2e64 DG |
810 | .B SESSION OPTIONS: |
811 | ||
747361fe MD |
812 | .TP |
813 | .BR "\-c, \-\-channel NAME" | |
814 | List details of a channel | |
815 | .TP | |
816 | .BR "\-d, \-\-domain" | |
817 | List available domain(s) | |
818 | .RE | |
819 | .PP | |
6991b181 | 820 | |
516f6cbe JG |
821 | .PP |
822 | \fBload\fP [OPTIONS] [NAME] | |
823 | .RS | |
824 | Load tracing session configuration | |
825 | ||
826 | If NAME is omitted, all session configurations found in both the user's session | |
bd88d988 | 827 | configuration directory (default: ~/.lttng/sessions/) and the system session |
cf53c06d DG |
828 | configuration directory (default: /etc/lttng/sessions/) will be loaded. Note |
829 | that the sessions in the user directory are loaded first and then the system | |
830 | wide directory are loaded. | |
516f6cbe JG |
831 | |
832 | .B OPTIONS: | |
833 | ||
834 | .TP | |
835 | .BR "\-h, \-\-help" | |
836 | Show summary of possible options and commands. | |
837 | .TP | |
838 | .BR "\-a, \-\-all" | |
839 | Load all session configurations (default). | |
840 | .TP | |
841 | .BR "\-i, \-\-input-path PATH" | |
bd88d988 DG |
842 | Specify the input path for session configurations. This overrides the default |
843 | session configuration directory. | |
516f6cbe JG |
844 | .TP |
845 | .BR "\-f, -\-force" | |
846 | Overwrite current session configuration(s) if a session of the same name | |
847 | already exists. | |
848 | .RE | |
849 | .PP | |
850 | ||
93ec662e JD |
851 | .PP |
852 | \fBmetadata\fP [OPTIONS] ACTION | |
853 | .RS | |
854 | Metadata command for a LTTng session. | |
855 | ||
856 | .B OPTIONS: | |
857 | ||
858 | .TP | |
859 | .BR "\-h, \-\-help" | |
860 | Show summary of possible options and commands. | |
861 | .TP | |
862 | .BR "\-\-list-options" | |
863 | Simple listing of options | |
864 | ||
865 | .PP | |
866 | .B ACTION: | |
867 | ||
868 | .TP | |
869 | \fBregenerate\fP [-s <NAME>] | |
870 | Regenerate the metadata of a session. This allows the user to regenerate the | |
871 | metadata after a major NTP correction and that way update the clock offset from | |
872 | epoch in the metadata. Only works on kernel, UST per-uid and non-live sessions. | |
873 | .RE | |
874 | .PP | |
875 | ||
516f6cbe JG |
876 | .PP |
877 | \fBsave\fP [OPTIONS] [SESSION] | |
878 | .RS | |
879 | Save tracing session configuration | |
880 | ||
881 | If SESSION is omitted, all session configurations will be saved to individual | |
553067af | 882 | \fB.lttng\fP files under the user's session configuration directory (default: |
bd88d988 DG |
883 | ~/.lttng/sessions/). The default session configuration file naming scheme is |
884 | \fBSESSION.lttng\fP. | |
516f6cbe | 885 | |
cf53c06d DG |
886 | For instance, a user in the tracing group saving a session from a root session |
887 | daemon will save it in her/his user directory. | |
888 | ||
516f6cbe JG |
889 | .B OPTIONS: |
890 | ||
891 | .TP | |
892 | .BR "\-h, \-\-help" | |
893 | Show summary of possible options and commands. | |
894 | .TP | |
895 | .BR "\-a, \-\-all" | |
896 | Save all session configurations (default). | |
897 | .TP | |
898 | .BR "\-o, \-\-output-path PATH" | |
553067af DG |
899 | Specify the output path for saved sessions. This overrides the default session |
900 | configuration directory. | |
516f6cbe JG |
901 | .TP |
902 | .BR "\-f, -\-force" | |
903 | Overwrite session configuration file if session name clashes. | |
904 | .RE | |
905 | .PP | |
906 | ||
7c96a096 MD |
907 | .PP |
908 | \fBset-session\fP NAME [OPTIONS] | |
909 | .RS | |
6991b181 DG |
910 | Set current session name |
911 | ||
912 | Will change the session name in the .lttngrc file. | |
6991b181 DG |
913 | |
914 | .B OPTIONS: | |
915 | ||
7c96a096 MD |
916 | .TP |
917 | .BR "\-h, \-\-help" | |
918 | Show summary of possible options and commands. | |
919 | .TP | |
920 | .BR "\-\-list-options" | |
921 | Simple listing of options | |
922 | .RE | |
923 | .PP | |
6991b181 | 924 | |
8df3bfe9 MD |
925 | .PP |
926 | \fBsnapshot\fP [OPTIONS] ACTION | |
927 | .RS | |
b872baea | 928 | Snapshot command for LTTng session. |
b872baea DG |
929 | |
930 | .B OPTIONS: | |
931 | ||
8df3bfe9 MD |
932 | .TP |
933 | .BR "\-h, \-\-help" | |
934 | Show summary of possible options and commands. | |
935 | .TP | |
936 | .BR "\-\-list-options" | |
937 | Simple listing of options | |
b872baea | 938 | |
8df3bfe9 | 939 | .PP |
b872baea DG |
940 | .B ACTION: |
941 | ||
8df3bfe9 | 942 | .TP |
b872baea DG |
943 | \fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL> |
944 | ||
88743287 | 945 | Setup and add a snapshot output for a session. Output is the destination |
b872baea DG |
946 | where the snapshot will be sent. Only one output is permitted. To change it, |
947 | you'll need to delete it and add back the new one. | |
948 | ||
8df3bfe9 | 949 | .TP |
b872baea DG |
950 | \fBdel-output\fP ID | NAME [-s <NAME>] |
951 | ||
88743287 JG |
952 | Delete an output for a session using the output's ID. You can either specify the |
953 | output by name or use its ID as returned by the list-output command. | |
b872baea | 954 | |
8df3bfe9 | 955 | .TP |
b872baea DG |
956 | \fBlist-output\fP [-s <NAME>] |
957 | ||
958 | List the output of a session. Attributes of the output are printed. | |
959 | ||
8df3bfe9 | 960 | .TP |
b872baea DG |
961 | \fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>] |
962 | ||
963 | Snapshot a session's buffer(s) for all domains. If an URL is specified, it is | |
964 | used instead of a previously added output. Specifying only a name or/and a max | |
965 | size will override the current output values. For instance, you can record a | |
966 | snapshot with a custom maximum size or with a different name. | |
967 | ||
8df3bfe9 | 968 | .nf |
1ac1098f | 969 | $ lttng snapshot add-output -n mysnapshot file:///data/snapshot |
b872baea DG |
970 | [...] |
971 | $ lttng snapshot record -n new_name_snapshot | |
8df3bfe9 | 972 | .fi |
b872baea DG |
973 | |
974 | The above will create a snapshot in /data/snapshot/new_name_snapshot* directory | |
975 | rather then in mysnapshot*/ | |
b872baea | 976 | |
8df3bfe9 MD |
977 | .PP |
978 | .B DETAILED ACTION OPTIONS | |
b872baea | 979 | |
8df3bfe9 MD |
980 | .TP |
981 | .BR "\-s, \-\-session NAME" | |
982 | Apply to session name. | |
983 | .TP | |
984 | .BR "\-n, \-\-name NAME" | |
985 | Name of the snapshot's output. | |
986 | .TP | |
987 | .BR "\-m, \-\-max-size SIZE" | |
eb82f91d | 988 | Maximum size in bytes of the snapshot. The maximum size does not include the |
a8f307d8 SM |
989 | metadata file. Human readable format is accepted: {+k,+M,+G}. For instance, |
990 | \-\-max-size 5M | |
8df3bfe9 MD |
991 | .TP |
992 | .BR "\-C, \-\-ctrl-url URL" | |
993 | Set control path URL. (Must use -D also) | |
994 | .TP | |
995 | .BR "\-D, \-\-data-url URL" | |
996 | Set data path URL. (Must use -C also) | |
997 | .RE | |
998 | .PP | |
b872baea | 999 | |
afb8ca1b MD |
1000 | .PP |
1001 | \fBstart\fP [NAME] [OPTIONS] | |
1002 | .RS | |
6991b181 DG |
1003 | Start tracing |
1004 | ||
1005 | It will start tracing for all tracers for a specific tracing session. | |
6991b181 | 1006 | If NAME is omitted, the session name is taken from the .lttngrc file. |
6991b181 DG |
1007 | |
1008 | .B OPTIONS: | |
1009 | ||
afb8ca1b MD |
1010 | .TP |
1011 | .BR "\-h, \-\-help" | |
1012 | Show summary of possible options and commands. | |
1013 | .TP | |
1014 | .BR "\-\-list-options" | |
1015 | Simple listing of options | |
1016 | .RE | |
1017 | .PP | |
6991b181 | 1018 | |
6c09bfdb MD |
1019 | .PP |
1020 | \fBstop\fP [NAME] [OPTIONS] | |
1021 | .RS | |
6991b181 DG |
1022 | Stop tracing |
1023 | ||
391b9c72 DG |
1024 | It will stop tracing for all tracers for a specific tracing session. Before |
1025 | returning, the command checks for data availability meaning that it will wait | |
1026 | until the trace is readable for the session. Use \-\-no-wait to avoid this | |
1027 | behavior. | |
6991b181 DG |
1028 | |
1029 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
1030 | |
1031 | .B OPTIONS: | |
1032 | ||
6c09bfdb MD |
1033 | .TP |
1034 | .BR "\-h, \-\-help" | |
1035 | Show summary of possible options and commands. | |
1036 | .TP | |
1037 | .BR "\-\-list-options" | |
1038 | Simple listing of options | |
3a7a166e MJ |
1039 | .TP |
1040 | .BR "\-\-no-wait" | |
6c09bfdb MD |
1041 | Don't wait for data availability. |
1042 | .RE | |
1043 | .PP | |
6991b181 | 1044 | |
c695a7bb PP |
1045 | .PP |
1046 | \fBtrack\fP (-k | -u) --pid [PID1[,PID2[,...]]] [OPTIONS] | |
1047 | .RS | |
1048 | Adds one or more entries to a tracker | |
1049 | ||
1050 | The \fBtrack\fP command adds one or more entries to a tracker. A tracker is | |
1051 | a whitelist of resources. Tracked resources are allowed to emit events, provided | |
1052 | those events are enabled (see the \fBenable-event\fP command). | |
1053 | ||
1054 | Tracker entries can be removed from the whitelist with the | |
1055 | \fBuntrack\fP command. | |
1056 | ||
1057 | As of this version, the only available tracker is the \fBPID tracker\fP. The | |
1058 | process ID (PID) tracker follows one or more process IDs; | |
1059 | only the processes with a tracked PID are allowed to emit events. By default, | |
1060 | all possible PIDs on the system are tracked: any process may emit enabled | |
1061 | events (equivalent of \fBlttng track \-\-pid \-\-all\fR for all domains). | |
1062 | ||
1063 | With the PID tracker, it is possible, for example, to record all system calls | |
1064 | called by a given process: | |
1065 | ||
1066 | .nf | |
1067 | $ lttng enable-event --kernel --all --syscall | |
1068 | $ lttng track --kernel --pid 2345 | |
1069 | $ lttng start | |
1070 | .fi | |
1071 | ||
1072 | If all the PIDs are tracked (i.e. \fBlttng track \-\-pid \-\-all\fR, which | |
1073 | is the default state of all domains when creating a tracing session), then | |
1074 | using the \fBtrack\fR command with one or more specific PIDs has the effect of | |
1075 | first removing all the PIDs from the whitelist, then adding the specified PIDs. | |
1076 | ||
1077 | Assume the maximum PID is 7 for the following examples: | |
1078 | ||
1079 | .nf | |
1080 | Initial whitelist: [0] [1] [2] [3] [4] [5] [6] [7] | |
1081 | ||
1082 | $ lttng track --userspace --pid 3,6,7 | |
1083 | ||
1084 | Whitelist: [ ] [ ] [ ] [3] [ ] [ ] [6] [7] | |
1085 | ||
1086 | $ lttng untrack --userspace --pid 7 | |
1087 | ||
1088 | Whitelist: [ ] [ ] [ ] [3] [ ] [ ] [6] [ ] | |
1089 | ||
1090 | $ lttng track --userspace --pid 1,5 | |
1091 | ||
1092 | Whitelist: [ ] [1] [ ] [3] [ ] [5] [6] [ ] | |
1093 | .fi | |
1094 | ||
1095 | It should be noted that the PID tracker tracks the numeric process IDs. | |
1096 | Should a process with a given ID exit and another process be given this | |
1097 | ID, then the latter would also be allowed to emit events. | |
1098 | ||
1099 | See the \fBuntrack\fR command's documentation for more details about | |
1100 | removing entries. | |
1101 | ||
1102 | .B OPTIONS: | |
1103 | ||
1104 | .TP | |
1105 | .BR "\-s, \-\-session NAME" | |
1106 | Apply to session name. | |
1107 | .TP | |
1108 | .BR "\-k, \-\-kernel" | |
1109 | Apply to the kernel tracer. | |
1110 | .TP | |
1111 | .BR "\-u, \-\-userspace" | |
1112 | Apply to the user space tracer. | |
1113 | .TP | |
1114 | .BR "\-p, \-\-pid [PIDS]" | |
1115 | Track process IDs PIDS (add to whitelist). | |
1116 | ||
1117 | PIDS is a comma-separated list of PIDs to add to the PID tracker. | |
1118 | ||
1119 | The PIDS argument must be omitted when also using the \fB\-\-all\fP option. | |
1120 | .TP | |
1121 | .BR "\-a, \-\-all" | |
1122 | Used in conjunction with an empty \fB\-\-pid\fP option: track all process IDs | |
1123 | (add all entries to whitelist). | |
1124 | .TP | |
1125 | .BR "\-h, \-\-help" | |
1126 | Show summary of possible options and commands. | |
1127 | .TP | |
1128 | .BR "\-\-list-options" | |
1129 | Simple listing of options | |
1130 | .RE | |
1131 | .PP | |
1132 | ||
09af9341 PP |
1133 | .PP |
1134 | \fBuntrack\fP (-k | -u) --pid [PID1[,PID2[,...]]] [OPTIONS] | |
1135 | .RS | |
1136 | Removes one or more entries from a tracker | |
1137 | ||
1138 | See the \fBtrack\fP command's documentation to learn more about LTTng | |
1139 | trackers. | |
1140 | ||
1141 | The \fBuntrack\fP command removes specific resources from a tracker. The | |
1142 | resources to remove must have been precedently added by the | |
1143 | \fBtrack\fP command. It is also possible to remove all the resources | |
1144 | from the whitelist using the \fB\-\-all\fR option. | |
1145 | ||
1146 | As of this version, the only available tracker is the \fBPID tracker\fP. | |
1147 | ||
1148 | One common operation is to create a tracing session, remove all the entries | |
1149 | from the PID tracker whitelist, start tracing, and then manually track PIDs | |
1150 | while tracing is active. | |
1151 | ||
1152 | Assume the maximum PID is 7 for the following examples: | |
1153 | ||
1154 | .nf | |
1155 | $ lttng create | |
1156 | ||
1157 | Initial whitelist: [0] [1] [2] [3] [4] [5] [6] [7] | |
1158 | ||
1159 | $ lttng untrack --userspace --pid --all | |
1160 | ||
1161 | Whitelist: [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] | |
1162 | ||
1163 | $ lttng enable-event --userspace ... | |
1164 | $ lttng start | |
1165 | ... | |
1166 | $ lttng track --userspace --pid 3,5 | |
1167 | ||
1168 | Whitelist: [ ] [ ] [ ] [3] [ ] [5] [ ] [ ] | |
1169 | ||
1170 | $ lttng track --userspace --pid 2 | |
1171 | ||
1172 | Whitelist: [ ] [ ] [2] [3] [ ] [5] [ ] [ ] | |
1173 | .fi | |
1174 | ||
1175 | See the \fBtrack\fR command's documentation for more details about | |
1176 | adding entries. | |
1177 | ||
1178 | .B OPTIONS: | |
1179 | ||
1180 | .TP | |
1181 | .BR "\-s, \-\-session NAME" | |
1182 | Apply to session name. | |
1183 | .TP | |
1184 | .BR "\-k, \-\-kernel" | |
1185 | Apply to the kernel tracer. | |
1186 | .TP | |
1187 | .BR "\-u, \-\-userspace" | |
1188 | Apply to the user space tracer. | |
1189 | .TP | |
1190 | .BR "\-p, \-\-pid [PIDS]" | |
1191 | Stop tracking process IDs PIDS (remove from whitelist). | |
1192 | ||
1193 | PIDS is a comma-separated list of PIDs to remove from the PID tracker. | |
1194 | ||
1195 | The PIDS argument must be omitted when also using the \fB\-\-all\fP option. | |
1196 | .TP | |
1197 | .BR "\-a, \-\-all" | |
1198 | Used in conjunction with an empty \fB\-\-pid\fP option: stop tracking all | |
1199 | process IDs (remove all entries from whitelist). | |
1200 | .TP | |
1201 | .BR "\-h, \-\-help" | |
1202 | Show summary of possible options and commands. | |
1203 | .TP | |
1204 | .BR "\-\-list-options" | |
1205 | Simple listing of options | |
1206 | .RE | |
1207 | .PP | |
1208 | ||
5975c30a MD |
1209 | .PP |
1210 | \fBversion\fP | |
1211 | .RS | |
6991b181 | 1212 | Show version information |
6991b181 DG |
1213 | |
1214 | .B OPTIONS: | |
1215 | ||
5975c30a MD |
1216 | .TP |
1217 | .BR "\-h, \-\-help" | |
1218 | Show summary of possible options and commands. | |
1219 | .TP | |
1220 | .BR "\-\-list-options" | |
1221 | Simple listing of options | |
1222 | .RE | |
1223 | .PP | |
6991b181 | 1224 | |
5b4c1410 MD |
1225 | .PP |
1226 | \fBview\fP [SESSION_NAME] [OPTIONS] | |
1227 | .RS | |
1228 | View traces of a tracing session. By default, the babeltrace viewer | |
1229 | will be used for text viewing. If SESSION_NAME is omitted, the session | |
1230 | name is taken from the .lttngrc file. | |
6991b181 DG |
1231 | |
1232 | .B OPTIONS: | |
1233 | ||
5b4c1410 MD |
1234 | .TP |
1235 | .BR "\-h, \-\-help" | |
1236 | Show this help | |
1237 | .TP | |
1238 | .BR "\-\-list-options" | |
1239 | Simple listing of options | |
1240 | .TP | |
1241 | .BR "\-t, \-\-trace-path PATH" | |
1242 | Trace directory path for the viewer | |
1243 | .TP | |
1244 | .BR "\-e, \-\-viewer CMD" | |
1245 | Specify viewer and/or options to use This will completely override the | |
1246 | default viewers so please make sure to specify the full command. The | |
1247 | trace directory path of the session will be appended at the end to the | |
1248 | arguments | |
1249 | .RE | |
1250 | .PP | |
6991b181 | 1251 | |
999ee001 DG |
1252 | .SH "JUL/LOG4J DOMAIN" |
1253 | ||
1254 | This section explains the JUL and LOG4J domain where JUL stands for Java Util | |
1255 | Logging. You can use these by using the \fBliblttng-ust-<domain>-jni.so\fP from | |
1256 | the lttng-ust(3) project. | |
acf47627 DG |
1257 | |
1258 | The LTTng Java Agent uses JNI to link the UST tracer to the Java application | |
1259 | that uses the agent. Thus, it behaves similarly to the UST domain (\-u). When | |
999ee001 DG |
1260 | enabling events, you enable a Logger name that will then be mapped to a default |
1261 | UST tracepoint called \fBlttng_jul:<domain>_event\fP in the | |
1262 | \fBlttng_<domain>_channel\fP. Using the lttng-ctl API, any JUL/LOG4J events | |
1263 | must use the tracepoint event type (same as \-\-tracepoint). | |
acf47627 | 1264 | |
999ee001 DG |
1265 | Because of the default immutable channel, the \fBenable-channel\fP command CAN |
1266 | NOT be used with the JUL and LOG4J domain thus not having any options. | |
acf47627 | 1267 | |
999ee001 DG |
1268 | Also, loglevels are supported. Use \fBlttng enable-event \-h\fP to list them. |
1269 | Wildcards are NOT supported except the "*" meaning all events (same as \-a). | |
acf47627 DG |
1270 | |
1271 | Exactly like the UST domain, if the Java application has the same UID as you, | |
1272 | you can trace it. Same goes for the tracing group accessing root applications. | |
1273 | ||
999ee001 DG |
1274 | Finally, you can list every Logger name that are available from registered |
1275 | applications to the session daemon by using \fBlttng list \-j\fP or \fB\-l\fP. | |
acf47627 | 1276 | |
999ee001 | 1277 | Here is an example on how to use the JUL domain. |
acf47627 DG |
1278 | |
1279 | .nf | |
1280 | $ lttng list -j | |
1281 | [...] | |
1282 | $ lttng create aSession | |
1283 | $ lttng enable-event -s aSession -j MyCustomLoggerName | |
1284 | $ lttng start | |
1285 | .fi | |
1286 | ||
1287 | More information can be found in the lttng-ust documentation, see | |
1288 | java-util-logging.txt | |
1289 | .PP | |
1290 | ||
c206d957 | 1291 | .SH "EXIT VALUES" |
b107a0b1 | 1292 | .PP |
6b8f2e64 DG |
1293 | On success 0 is returned and a positive value on error. Value of 1 means a command |
1294 | error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that | |
1295 | something went wrong during the command. | |
c206d957 | 1296 | |
6b8f2e64 | 1297 | Any other value above 10, please refer to |
b107a0b1 | 1298 | .BR "<lttng/lttng-error.h>" |
6b8f2e64 DG |
1299 | for a detailed list or use lttng_strerror() to get a human readable string of |
1300 | the error code. | |
c206d957 | 1301 | .PP |
b107a0b1 | 1302 | |
6991b181 DG |
1303 | .SH "ENVIRONMENT VARIABLES" |
1304 | ||
1305 | .PP | |
1306 | Note that all command line options override environment variables. | |
1307 | .PP | |
1308 | ||
1309 | .PP | |
05833633 | 1310 | .IP "LTTNG_SESSIOND_PATH" |
c9e32613 DG |
1311 | Allows one to specify the full session daemon binary path to lttng command line |
1312 | tool. You can also use \-\-sessiond-path option having the same effect. | |
b107a0b1 MD |
1313 | .PP |
1314 | ||
516f6cbe JG |
1315 | .PP |
1316 | .IP "LTTNG_SESSION_CONFIG_XSD_PATH" | |
1317 | Set the path in which the \fBsession.xsd\fP session configuration schema may be | |
1318 | found. | |
1319 | .PP | |
1320 | ||
6991b181 | 1321 | .SH "SEE ALSO" |
6b8f2e64 DG |
1322 | .BR babeltrace(1), |
1323 | .BR lttng-ust(3), | |
1324 | .BR lttng-sessiond(8), | |
1325 | .BR lttng-relayd(8), | |
464bd4b0 | 1326 | .BR lttng-crash(1), |
b107a0b1 | 1327 | |
6991b181 DG |
1328 | .SH "BUGS" |
1329 | ||
b107a0b1 | 1330 | .PP |
6991b181 | 1331 | If you encounter any issues or usability problem, please report it on our |
6b8f2e64 | 1332 | mailing list <lttng-dev@lists.lttng.org> to help improve this project or |
eb82f91d | 1333 | at https://bugs.lttng.org which is a bug tracker. |
b107a0b1 MD |
1334 | .PP |
1335 | ||
6991b181 DG |
1336 | .SH "CREDITS" |
1337 | ||
1338 | .PP | |
c9e32613 | 1339 | lttng is distributed under the GNU General Public License version 2. See the file |
6991b181 DG |
1340 | COPYING for details. |
1341 | .PP | |
1342 | A Web site is available at http://lttng.org for more information on the LTTng | |
1343 | project. | |
1344 | .PP | |
1345 | You can also find our git tree at http://git.lttng.org. | |
1346 | .PP | |
1347 | Mailing lists for support and development: <lttng-dev@lists.lttng.org>. | |
1348 | .PP | |
1349 | You can find us on IRC server irc.oftc.net (OFTC) in #lttng. | |
1350 | .PP | |
1351 | .SH "THANKS" | |
1352 | ||
1353 | .PP | |
1354 | Thanks to Yannick Brosseau without whom this project would never have been so | |
1355 | lean and mean! Also thanks to the Ericsson teams working on tracing which | |
fa072eae | 1356 | helped us greatly with detailed bug reports and unusual test cases. |
6991b181 DG |
1357 | |
1358 | Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA | |
1359 | maintainer) and Jon Bernard for our Debian packages. | |
1360 | ||
1361 | Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de | |
1362 | Montreal for the LTTng journey. | |
c9e32613 | 1363 | .PP |
6991b181 DG |
1364 | .SH "AUTHORS" |
1365 | ||
1366 | .PP | |
1367 | lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and | |
1368 | David Goulet. More people have since contributed to it. It is currently | |
9b22d135 | 1369 | maintained by Jérémie Galarneau <jeremie.galarneau@efficios.com>. |
6991b181 | 1370 | .PP |