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