4 .\" This code is free software; you can redistribute it and/or modify it
5 .\" under the terms of the GNU General Public License version 2 only, as
6 .\" published by the Free Software Foundation.
7 .\"
8 .\" This code is distributed in the hope that it will be useful, but WITHOUT
9 .\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 .\" FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 .\" version 2 for more details (a copy is included in the LICENSE file that
12 .\" accompanied this code).
13 .\"
14 .\" You should have received a copy of the GNU General Public License version
15 .\" 2 along with this work; if not, write to the Free Software Foundation,
16 .\" Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 .\"
18 .\" Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 .\" or visit www.oracle.com if you need additional information or have any
20 .\" questions.
21 .\"
22 .\" Automatically generated by Pandoc 2.3.1
23 .\"
24 .TH "JCMD" "1" "2018" "JDK 13" "JDK Commands"
25 .hy
26 .SH NAME
27 .PP
28 jcmd \- send diagnostic command requests to a running Java Virtual
29 Machine (JVM)
30 .SH SYNOPSIS
31 .PP
32 \f[CB]jcmd\f[R] [\f[I]pid\f[R] | \f[I]main\-class\f[R]] \f[I]command\f[R]...
33 | \f[CB]PerfCounter.print\f[R] | \f[CB]\-f\f[R] \f[I]filename\f[R]
34 .PP
35 \f[CB]jcmd\f[R] [\f[CB]\-l\f[R]]
36 .PP
37 \f[CB]jcmd\f[R] \f[CB]\-h\f[R]
38 .TP
39 .B \f[I]pid\f[R]
40 When used, the \f[CB]jcmd\f[R] utility sends the diagnostic command
41 request to the process ID for the Java process.
42 .RS
43 .RE
44 .TP
72 .B \f[CB]\-f\f[R] \f[I]filename\f[R]
73 Reads and executes commands from a specified file, \f[I]filename\f[R].
74 .RS
75 .RE
76 .TP
77 .B \f[CB]\-l\f[R]
78 Displays the list of Java Virtual Machine process identifiers that are
79 not running in a separate docker process along with the main class and
80 command\-line arguments that were used to launch the process.
81 If the JVM is in a docker process, you must use tools such as
82 \f[CB]ps\f[R] to look up the PID.
83 .RS
84 .PP
85 \f[B]Note:\f[R]
86 .PP
87 Using \f[CB]jcmd\f[R] without arguments is the same as using
88 \f[CB]jcmd\ \-l\f[R].
89 .RE
90 .TP
91 .B \f[CB]\-h\f[R]
92 Displays the\f[CB]jcmd\f[R] utility\[aq]s command\-line help.
93 .RS
94 .RE
95 .SH DESCRIPTION
96 .PP
97 The \f[CB]jcmd\f[R] utility is used to send diagnostic command requests to
98 the JVM.
99 It must be used on the same machine on which the JVM is running, and
100 have the same effective user and group identifiers that were used to
101 launch the JVM.
102 Each diagnostic command has its own set of arguments.
103 To display the description, syntax, and a list of available arguments
104 for a diagnostic command, use the name of the command as the argument.
105 For example:
106 .RS
107 .PP
108 \f[CB]jcmd\f[R] \f[I]pid\f[R] \f[CB]help\f[R] \f[I]command\f[R]
109 .RE
110 .PP
111 If arguments contain spaces, then you must surround them with single or
112 double quotation marks (\f[CB]\[aq]\f[R] or \f[CB]"\f[R]).
232 .B \f[CB]GC.class_histogram\f[R] [\f[I]options\f[R]]
233 Provides statistics about the Java heap usage.
234 .RS
235 .PP
236 Impact: High \-\-\- depends on Java heap size and content.
237 .PP
238 Permission: \f[CB]java.lang.management.ManagementPermission(monitor)\f[R]
239 .PP
240 \f[B]Note:\f[R]
241 .PP
242 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
243 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
244 .PP
245 \f[I]options\f[R]:
246 .IP \[bu] 2
247 \f[CB]\-all\f[R]: (Optional) Inspects all objects, including unreachable
248 objects (BOOLEAN, false)
249 .RE
250 .TP
251 .B \f[CB]GC.class_stats\f[R] [\f[I]options\f[R]] [\f[I]arguments\f[R]]
252 Provide statistics about Java class meta data.
253 .RS
254 .PP
255 Impact: High \-\-\- depends on Java heap size and content.
256 .PP
257 \f[B]Note:\f[R]
258 .PP
259 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
260 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
261 .PP
262 \f[I]options\f[R]:
263 .IP \[bu] 2
264 \f[CB]\-all\f[R]: (Optional) Shows all columns (BOOLEAN, false)
265 .IP \[bu] 2
266 \f[CB]\-csv\f[R]: (Optional) Prints in CSV (comma\-separated values)
267 format for spreadsheets (BOOLEAN, false)
268 .IP \[bu] 2
269 \f[CB]\-help\f[R]: (Optional) Shows the meaning of all the columns
270 (BOOLEAN, false)
271 .PP
272 \f[I]arguments\f[R]:
340 Impact: Medium
341 .PP
342 Permission: \f[CB]java.lang.management.ManagementPermission(monitor)\f[R]
343 .RE
344 .TP
345 .B \f[CB]GC.run\f[R]
346 Calls \f[CB]java.lang.System.gc()\f[R].
347 .RS
348 .PP
349 Impact: Medium \-\-\- depends on the Java heap size and content.
350 .RE
351 .TP
352 .B \f[CB]GC.run_finalization\f[R]
353 Calls \f[CB]java.lang.System.runFinalization()\f[R].
354 .RS
355 .PP
356 Impact: Medium \-\-\- depends on the Java content.
357 .RE
358 .TP
359 .B \f[CB]JFR.check\f[R] [\f[I]options\f[R]]
360 See \f[B]JFR.check\f[R]
361 [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-DA391CC1\-B5D8\-44F1\-AEDD\-9A534C8DD009]
362 in the Java Flight Recorder Command Reference.
363 .RS
364 .RE
365 .TP
366 .B \f[CB]JFR.configure\f[R] [\f[I]options\f[R]]
367 See \f[B]JFR.configure\f[R]
368 [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-737D234E\-FD69\-4E8E\-A9F7\-06AE073648DD]
369 in the Java Flight Recorder Command Reference.
370 .RS
371 .RE
372 .TP
373 .B \f[CB]JFR.dump\f[R] [\f[I]options\f[R]]
374 See \f[B]JFR.dump\f[R]
375 [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-6EB11926\-4DAF\-4B99\-AF20\-7FCD284EE6C1]
376 in the Java Flight Recorder Command Reference.
377 .RS
378 .RE
379 .TP
380 .B \f[CB]JFR.start\f[R] [\f[I]options\f[R]]
381 See \f[B]JFR.start\f[R]
382 [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-8DC13618\-1515\-4479\-B0FC\-9F4394BE5455]
383 in the Java Flight Recorder Command Reference.
384 .RS
385 .RE
386 .TP
387 .B \f[CB]JFR.stop\f[R] [\f[I]options\f[R]]
388 See \f[B]JFR.stop\f[R]
389 [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-66CC94C8\-8EDF\-4BB6\-8E7A\-49973025D4D9]
390 in the Java Flight Recorder Command Reference.
391 .RS
392 .RE
393 .TP
394 .B \f[CB]JVMTI.agent_load\f[R] [\f[I]arguments\f[R]]
395 Loads JVMTI native agent.
396 .RS
397 .PP
398 Impact: Low
399 .PP
400 Permission: \f[CB]java.lang.management.ManagementPermission(control)\f[R]
401 .PP
402 \f[I]arguments\f[R]:
403 .IP \[bu] 2
404 \f[I]library path\f[R]: Absolute path of the JVMTI agent to load.
405 (STRING, no default value)
406 .IP \[bu] 2
407 \f[I]agent option\f[R]: (Optional) Option string to pass the agent.
408 (STRING, no default value)
409 .RE
410 .TP
411 .B \f[CB]JVMTI.data_dump\f[R]
|
4 .\" This code is free software; you can redistribute it and/or modify it
5 .\" under the terms of the GNU General Public License version 2 only, as
6 .\" published by the Free Software Foundation.
7 .\"
8 .\" This code is distributed in the hope that it will be useful, but WITHOUT
9 .\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 .\" FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 .\" version 2 for more details (a copy is included in the LICENSE file that
12 .\" accompanied this code).
13 .\"
14 .\" You should have received a copy of the GNU General Public License version
15 .\" 2 along with this work; if not, write to the Free Software Foundation,
16 .\" Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 .\"
18 .\" Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 .\" or visit www.oracle.com if you need additional information or have any
20 .\" questions.
21 .\"
22 .\" Automatically generated by Pandoc 2.3.1
23 .\"
24 .TH "JCMD" "1" "2020" "JDK 14" "JDK Commands"
25 .hy
26 .SH NAME
27 .PP
28 jcmd \- send diagnostic command requests to a running Java Virtual
29 Machine (JVM)
30 .SH SYNOPSIS
31 .PP
32 \f[CB]jcmd\f[R] [\f[I]pid\f[R] | \f[I]main\-class\f[R]] \f[I]command\f[R]...
33 | \f[CB]PerfCounter.print\f[R] | \f[CB]\-f\f[R] \f[I]filename\f[R]
34 .PP
35 \f[CB]jcmd\f[R] [\f[CB]\-l\f[R]]
36 .PP
37 \f[CB]jcmd\f[R] \f[CB]\-h\f[R]
38 .TP
39 .B \f[I]pid\f[R]
40 When used, the \f[CB]jcmd\f[R] utility sends the diagnostic command
41 request to the process ID for the Java process.
42 .RS
43 .RE
44 .TP
72 .B \f[CB]\-f\f[R] \f[I]filename\f[R]
73 Reads and executes commands from a specified file, \f[I]filename\f[R].
74 .RS
75 .RE
76 .TP
77 .B \f[CB]\-l\f[R]
78 Displays the list of Java Virtual Machine process identifiers that are
79 not running in a separate docker process along with the main class and
80 command\-line arguments that were used to launch the process.
81 If the JVM is in a docker process, you must use tools such as
82 \f[CB]ps\f[R] to look up the PID.
83 .RS
84 .PP
85 \f[B]Note:\f[R]
86 .PP
87 Using \f[CB]jcmd\f[R] without arguments is the same as using
88 \f[CB]jcmd\ \-l\f[R].
89 .RE
90 .TP
91 .B \f[CB]\-h\f[R]
92 Displays the \f[CB]jcmd\f[R] utility\[aq]s command\-line help.
93 .RS
94 .RE
95 .SH DESCRIPTION
96 .PP
97 The \f[CB]jcmd\f[R] utility is used to send diagnostic command requests to
98 the JVM.
99 It must be used on the same machine on which the JVM is running, and
100 have the same effective user and group identifiers that were used to
101 launch the JVM.
102 Each diagnostic command has its own set of arguments.
103 To display the description, syntax, and a list of available arguments
104 for a diagnostic command, use the name of the command as the argument.
105 For example:
106 .RS
107 .PP
108 \f[CB]jcmd\f[R] \f[I]pid\f[R] \f[CB]help\f[R] \f[I]command\f[R]
109 .RE
110 .PP
111 If arguments contain spaces, then you must surround them with single or
112 double quotation marks (\f[CB]\[aq]\f[R] or \f[CB]"\f[R]).
232 .B \f[CB]GC.class_histogram\f[R] [\f[I]options\f[R]]
233 Provides statistics about the Java heap usage.
234 .RS
235 .PP
236 Impact: High \-\-\- depends on Java heap size and content.
237 .PP
238 Permission: \f[CB]java.lang.management.ManagementPermission(monitor)\f[R]
239 .PP
240 \f[B]Note:\f[R]
241 .PP
242 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
243 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
244 .PP
245 \f[I]options\f[R]:
246 .IP \[bu] 2
247 \f[CB]\-all\f[R]: (Optional) Inspects all objects, including unreachable
248 objects (BOOLEAN, false)
249 .RE
250 .TP
251 .B \f[CB]GC.class_stats\f[R] [\f[I]options\f[R]] [\f[I]arguments\f[R]]
252 (Deprecated) Provide statistics about Java class meta data.
253 .RS
254 .PP
255 Impact: High \-\-\- depends on Java heap size and content.
256 .PP
257 \f[B]Note:\f[R]
258 .PP
259 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
260 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
261 .PP
262 \f[I]options\f[R]:
263 .IP \[bu] 2
264 \f[CB]\-all\f[R]: (Optional) Shows all columns (BOOLEAN, false)
265 .IP \[bu] 2
266 \f[CB]\-csv\f[R]: (Optional) Prints in CSV (comma\-separated values)
267 format for spreadsheets (BOOLEAN, false)
268 .IP \[bu] 2
269 \f[CB]\-help\f[R]: (Optional) Shows the meaning of all the columns
270 (BOOLEAN, false)
271 .PP
272 \f[I]arguments\f[R]:
340 Impact: Medium
341 .PP
342 Permission: \f[CB]java.lang.management.ManagementPermission(monitor)\f[R]
343 .RE
344 .TP
345 .B \f[CB]GC.run\f[R]
346 Calls \f[CB]java.lang.System.gc()\f[R].
347 .RS
348 .PP
349 Impact: Medium \-\-\- depends on the Java heap size and content.
350 .RE
351 .TP
352 .B \f[CB]GC.run_finalization\f[R]
353 Calls \f[CB]java.lang.System.runFinalization()\f[R].
354 .RS
355 .PP
356 Impact: Medium \-\-\- depends on the Java content.
357 .RE
358 .TP
359 .B \f[CB]JFR.check\f[R] [\f[I]options\f[R]]
360 Show information about a running flight recording
361 .RS
362 .PP
363 Impact: Low
364 .PP
365 \f[B]Note:\f[R]
366 .PP
367 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
368 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
369 If no parameters are entered, information for all active recordings is
370 shown.
371 .PP
372 \f[I]options\f[R]:
373 .IP \[bu] 2
374 \f[CB]name\f[R]: (Optional) Name of the flight recording.
375 (STRING, no default value)
376 .IP \[bu] 2
377 \f[CB]verbose\f[R]: (Optional) Flag for printing the event settings for
378 the recording (BOOLEAN, false)
379 .RE
380 .TP
381 .B \f[CB]JFR.configure\f[R] [\f[I]options\f[R]]
382 Set the parameters for a flight recording
383 .RS
384 .PP
385 Impact: Low
386 .PP
387 \f[B]Note:\f[R]
388 .PP
389 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
390 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
391 If no parameters are entered, the current settings are displayed.
392 .PP
393 \f[I]options\f[R]:
394 .IP \[bu] 2
395 \f[CB]globalbuffercount\f[R]: (Optional) Number of global buffers.
396 This option is a legacy option: change the \f[CB]memorysize\f[R] parameter
397 to alter the number of global buffers.
398 This value cannot be changed once JFR has been initalized.
399 (STRING, default determined by the value for \f[CB]memorysize\f[R])
400 .IP \[bu] 2
401 \f[CB]globalbuffersize\f[R]: (Optional) Size of the global buffers, in
402 bytes.
403 This option is a legacy option: change the \f[CB]memorysize\f[R] parameter
404 to alter the size of the global buffers.
405 This value cannot be changed once JFR has been initalized.
406 (STRING, default determined by the value for \f[CB]memorysize\f[R])
407 .IP \[bu] 2
408 \f[CB]maxchunksize\f[R]: (Optional) Maximum size of an individual data
409 chunk in bytes if one of the following suffixes is not used: \[aq]m\[aq]
410 or \[aq]M\[aq] for megabytes OR \[aq]g\[aq] or \[aq]G\[aq] for
411 gigabytes.
412 This value cannot be changed once JFR has been initialized.
413 (STRING, 12M)
414 .IP \[bu] 2
415 \f[CB]memorysize\f[R]: (Optional) Overall memory size, in bytes if one of
416 the following suffixes is not used: \[aq]m\[aq] or \[aq]M\[aq] for
417 megabytes OR \[aq]g\[aq] or \[aq]G\[aq] for gigabytes.
418 This value cannot be changed once JFR has been initialized.
419 (STRING, 10M)
420 .IP \[bu] 2
421 \f[CB]repositorypath\f[R]: (Optional) Path to the location where
422 recordings are stored until they are written to a permanent file.
423 (STRING, The default location is the temporary directory for the
424 operating system.
425 On Linux operating systems, the temporary directory is \f[CB]/tmp\f[R].
426 On Windwows, the temporary directory is specified by the \f[CB]TMP\f[R]
427 environment variable.)
428 .IP \[bu] 2
429 \f[CB]stackdepth\f[R]: (Optional) Stack depth for stack traces.
430 Setting this value greater than the default of 64 may cause a
431 performance degradation.
432 This value cannot be changed once JFR has been initialized.
433 (LONG, 64)
434 .IP \[bu] 2
435 \f[CB]thread_buffer_size\f[R]: (Optional) Local buffer size for each
436 thread in bytes if one of the following suffixes is not used:
437 \[aq]k\[aq] or \[aq]K\[aq] for kilobytes or \[aq]m\[aq] or \[aq]M\[aq]
438 for megabytes.
439 Overriding this parameter could reduce performance and is not
440 recommended.
441 This value cannot be changed once JFR has been initialized.
442 (STRING, 8k)
443 .IP \[bu] 2
444 \f[CB]samplethreads\f[R]: (Optional) Flag for activating thread sampling.
445 (BOOLEAN, true)
446 .RE
447 .TP
448 .B \f[CB]JFR.dump\f[R] [\f[I]options\f[R]]
449 Write data to a file while a flight recording is running
450 .RS
451 .PP
452 Impact: Low
453 .PP
454 \f[B]Note:\f[R]
455 .PP
456 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
457 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
458 No options are required.
459 The recording continues to run after the data is written.
460 .PP
461 \f[I]options\f[R]:
462 .IP \[bu] 2
463 \f[CB]begin\f[R]: (Optional) Specify the time from which recording data
464 will be included in the dump file.
465 The format is specified as local time.
466 (STRING, no default value)
467 .IP \[bu] 2
468 \f[CB]end\f[R]: (Optional) Specify the time to which recording data will
469 be included in the dump file.
470 The format is specified as local time.
471 (STRING, no default value)
472 .RS 2
473 .PP
474 \f[B]Note:\f[R] For both \f[CB]begin\f[R] and \f[CB]end\f[R], the time must
475 be in a format that can be read by java.time.LocalTime::parse(STRING),
476 java.time.LocalDateTime::parse(STRING) or
477 java.time.Instant::parse(STRING).
478 For example, "13:20:15", "2020\-03\-17T09:00:00" or
479 "2020\-03\-17T09:00:00Z".
480 .PP
481 \f[B]Note:\f[R] \f[CB]begin\f[R] and \f[CB]end\f[R] times correspond to the
482 timestamps found within the recorded information in the flight recording
483 data.
484 .PP
485 Another option is to use a time relative to the current time that is
486 specified by a negative integer followed by "s", "m" or "h".
487 For example, "\-12h", "\-15m" or "\-30s"
488 .RE
489 .IP \[bu] 2
490 \f[CB]filename\f[R]: (Optional) Name of the file to which the flight
491 recording data is dumped.
492 If no filename is given, a filename is generated from the PID and the
493 current date.
494 The filename may also be a directory in which case, the filename is
495 generated from the PID and the current date in the specified directory.
496 (STRING, no default value)
497 .IP \[bu] 2
498 \f[CB]maxage\f[R]: (Optional) Length of time for dumping the flight
499 recording data to a file.
500 (INTEGER followed by \[aq]s\[aq] for seconds \[aq]m\[aq] for minutes or
501 \[aq]h\[aq] for hours, no default value)
502 .IP \[bu] 2
503 \f[CB]maxsize\f[R]: (Optional) Maximum size for the amount of data to dump
504 from a flight recording in bytes if one of the following suffixes is not
505 used: \[aq]m\[aq] or \[aq]M\[aq] for megabytes OR \[aq]g\[aq] or
506 \[aq]G\[aq] for gigabytes.
507 (STRING, no default value)
508 .IP \[bu] 2
509 \f[CB]name\f[R]: (Optional) Name of the recording.
510 If no name is given, data from all recordings is dumped.
511 (STRING, no default value)
512 .IP \[bu] 2
513 \f[CB]path\-to\-gc\-root\f[R]: (Optional) Flag for saving the path to
514 garbage collection (GC) roots at the time the recording data is dumped.
515 The path information is useful for finding memory leaks but collecting
516 it can cause the application to pause for a short period of time.
517 Turn on this flag only when you have an application that you suspect has
518 a memory leak.
519 (BOOLEAN, false)
520 .RE
521 .TP
522 .B \f[CB]JFR.start\f[R] [\f[I]options\f[R]]
523 Start a flight recording
524 .RS
525 .PP
526 Impact: Low
527 .PP
528 \f[B]Note:\f[R]
529 .PP
530 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
531 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
532 If no parameters are entered, then a recording is started with default
533 values.
534 .PP
535 \f[I]options\f[R]:
536 .IP \[bu] 2
537 \f[CB]delay\f[R]: (Optional) Length of time to wait before starting to
538 record (INTEGER followed by \[aq]s\[aq] for seconds \[aq]m\[aq] for
539 minutes or \[aq]h\[aq] for hours, 0s)
540 .IP \[bu] 2
541 \f[CB]disk\f[R]: (Optional) Flag for also writing the data to disk while
542 recording (BOOLEAN, true)
543 .IP \[bu] 2
544 \f[CB]dumponexit\f[R]: (Optional) Flag for writing the recording to disk
545 when the Java Virtual Machine (JVM) shuts down.
546 If set to \[aq]true\[aq] and no value is given for \f[CB]filename\f[R],
547 the recording is written to a file in the directory where the process
548 was started.
549 The file name is a system\-generated name that contains the process ID,
550 the recording ID and the current time stamp.
551 (For example: \f[CB]id\-1\-2019_12_12_10_41.jfr\f[R]) (BOOLEAN, false)
552 .IP \[bu] 2
553 \f[CB]duration\f[R]: (Optional) Length of time to record.
554 Note that \f[CB]0s\f[R] means forever (INTEGER followed by \[aq]s\[aq] for
555 seconds \[aq]m\[aq] for minutes or \[aq]h\[aq] for hours, 0s)
556 .IP \[bu] 2
557 \f[CB]filename\f[R]: (Optional) Name of the file to which the flight
558 recording data is written when the recording is stopped.
559 If no filename is given, a filename is generated from the PID and the
560 current date and is placed in the directory where the process was
561 started.
562 The filename may also be a directory in which case, the filename is
563 generated from the PID and the current date in the specified directory.
564 (STRING, no default value)
565 .IP \[bu] 2
566 \f[CB]maxage\f[R]: (Optional) Maximum time to keep the recorded data on
567 disk.
568 This parameter is valid only when the \f[CB]disk\f[R] parameter is set to
569 \f[CB]true\f[R].
570 Note \f[CB]0s\f[R] means forever.
571 (INTEGER followed by \[aq]s\[aq] for seconds \[aq]m\[aq] for minutes or
572 \[aq]h\[aq] for hours, 0s)
573 .IP \[bu] 2
574 \f[CB]maxsize\f[R]: (Optional) Maximum size of the data to keep on disk in
575 bytes if one of the following suffixes is not used: \[aq]m\[aq] or
576 \[aq]M\[aq] for megabytes OR \[aq]g\[aq] or \[aq]G\[aq] for gigabytes.
577 This parameter is valid only when the \f[CB]disk\f[R] parameter is set to
578 \[aq]true\[aq].
579 The value must not be less than the value for the \f[CB]maxchunksize\f[R]
580 parameter set with the \f[CB]JFR.configure\f[R] command.
581 (STRING, 0 (no maximum size))
582 .IP \[bu] 2
583 \f[CB]name\f[R]: (Optional) Name of the recording.
584 If no name is provided, a name is generated.
585 Make note of the generated name that is shown in the response to the
586 command so that you can use it with other commands.
587 (STRING, system\-generated default name)
588 .IP \[bu] 2
589 \f[CB]path\-to\-gc\-root\f[R]: (Optional) Flag for saving the path to
590 garbage collection (GC) roots at the end of a recording.
591 The path information is useful for finding memory leaks but collecting
592 it is time consuming.
593 Turn on this flag only when you have an application that you suspect has
594 a memory leak.
595 If the \f[CB]settings\f[R] parameter is set to \[aq]profile\[aq], then the
596 information collected includes the stack trace from where the potential
597 leaking object was allocated.
598 (BOOLEAN, false)
599 .IP \[bu] 2
600 \f[CB]settings\f[R]: (Optional) Name of the settings file that identifies
601 which events to record.
602 To specify more than one file, separate the names with a comma
603 (\[aq],\[aq]).
604 Include the path if the file is not in \f[CB]JAVA\-HOME\f[R]/lib/jfr.
605 The following profiles are included with the JDK in the
606 \f[CB]JAVA\-HOME\f[R]/lib/jfr directory: \[aq]default.jfc\[aq]: collects a
607 predefined set of information with low overhead, so it has minimal
608 impact on performance and can be used with recordings that run
609 continuously; \[aq]profile.jfc\[aq]: Provides more data than the
610 \[aq]default.jfc\[aq] profile, but with more overhead and impact on
611 performance.
612 Use this configuration for short periods of time when more information
613 is needed.
614 Use \f[CB]none\f[R] to start a recording without a predefined
615 configuration file.
616 (STRING, \f[CB]JAVA\-HOME\f[R]/lib/jfr/default.jfc)
617 .RE
618 .TP
619 .B \f[CB]JFR.stop\f[R] [\f[I]options\f[R]]
620 Stop a flight recording
621 .RS
622 .PP
623 Impact: Low
624 .PP
625 \f[B]Note:\f[R]
626 .PP
627 The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
628 \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
629 If no parameters are entered, then no recording is stopped.
630 .PP
631 \f[I]options\f[R]:
632 .IP \[bu] 2
633 \f[CB]filename\f[R]: (Optional) Name of the file to which the recording is
634 written when the recording is stopped.
635 If no path is provided, the data from the recording is discarded.
636 (STRING, no default value)
637 .IP \[bu] 2
638 \f[CB]name\f[R]: (Optional) Name of the recording (STRING, no default
639 value)
640 .RE
641 .TP
642 .B \f[CB]JVMTI.agent_load\f[R] [\f[I]arguments\f[R]]
643 Loads JVMTI native agent.
644 .RS
645 .PP
646 Impact: Low
647 .PP
648 Permission: \f[CB]java.lang.management.ManagementPermission(control)\f[R]
649 .PP
650 \f[I]arguments\f[R]:
651 .IP \[bu] 2
652 \f[I]library path\f[R]: Absolute path of the JVMTI agent to load.
653 (STRING, no default value)
654 .IP \[bu] 2
655 \f[I]agent option\f[R]: (Optional) Option string to pass the agent.
656 (STRING, no default value)
657 .RE
658 .TP
659 .B \f[CB]JVMTI.data_dump\f[R]
|