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src/jdk.jcmd/share/man/jcmd.1
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*** 19,29 ****
.\" or visit www.oracle.com if you need additional information or have any
.\" questions.
.\"
.\" Automatically generated by Pandoc 2.3.1
.\"
! .TH "JCMD" "1" "2018" "JDK 13" "JDK Commands"
.hy
.SH NAME
.PP
jcmd \- send diagnostic command requests to a running Java Virtual
Machine (JVM)
--- 19,29 ----
.\" or visit www.oracle.com if you need additional information or have any
.\" questions.
.\"
.\" Automatically generated by Pandoc 2.3.1
.\"
! .TH "JCMD" "1" "2020" "JDK 14" "JDK Commands"
.hy
.SH NAME
.PP
jcmd \- send diagnostic command requests to a running Java Virtual
Machine (JVM)
*** 87,97 ****
Using \f[CB]jcmd\f[R] without arguments is the same as using
\f[CB]jcmd\ \-l\f[R].
.RE
.TP
.B \f[CB]\-h\f[R]
! Displays the\f[CB]jcmd\f[R] utility\[aq]s command\-line help.
.RS
.RE
.SH DESCRIPTION
.PP
The \f[CB]jcmd\f[R] utility is used to send diagnostic command requests to
--- 87,97 ----
Using \f[CB]jcmd\f[R] without arguments is the same as using
\f[CB]jcmd\ \-l\f[R].
.RE
.TP
.B \f[CB]\-h\f[R]
! Displays the \f[CB]jcmd\f[R] utility\[aq]s command\-line help.
.RS
.RE
.SH DESCRIPTION
.PP
The \f[CB]jcmd\f[R] utility is used to send diagnostic command requests to
*** 247,257 ****
\f[CB]\-all\f[R]: (Optional) Inspects all objects, including unreachable
objects (BOOLEAN, false)
.RE
.TP
.B \f[CB]GC.class_stats\f[R] [\f[I]options\f[R]] [\f[I]arguments\f[R]]
! Provide statistics about Java class meta data.
.RS
.PP
Impact: High \-\-\- depends on Java heap size and content.
.PP
\f[B]Note:\f[R]
--- 247,257 ----
\f[CB]\-all\f[R]: (Optional) Inspects all objects, including unreachable
objects (BOOLEAN, false)
.RE
.TP
.B \f[CB]GC.class_stats\f[R] [\f[I]options\f[R]] [\f[I]arguments\f[R]]
! (Deprecated) Provide statistics about Java class meta data.
.RS
.PP
Impact: High \-\-\- depends on Java heap size and content.
.PP
\f[B]Note:\f[R]
*** 355,396 ****
.PP
Impact: Medium \-\-\- depends on the Java content.
.RE
.TP
.B \f[CB]JFR.check\f[R] [\f[I]options\f[R]]
! See \f[B]JFR.check\f[R]
! [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-DA391CC1\-B5D8\-44F1\-AEDD\-9A534C8DD009]
! in the Java Flight Recorder Command Reference.
.RS
.RE
.TP
.B \f[CB]JFR.configure\f[R] [\f[I]options\f[R]]
! See \f[B]JFR.configure\f[R]
! [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-737D234E\-FD69\-4E8E\-A9F7\-06AE073648DD]
! in the Java Flight Recorder Command Reference.
.RS
.RE
.TP
.B \f[CB]JFR.dump\f[R] [\f[I]options\f[R]]
! See \f[B]JFR.dump\f[R]
! [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-6EB11926\-4DAF\-4B99\-AF20\-7FCD284EE6C1]
! in the Java Flight Recorder Command Reference.
.RS
.RE
.TP
.B \f[CB]JFR.start\f[R] [\f[I]options\f[R]]
! See \f[B]JFR.start\f[R]
! [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-8DC13618\-1515\-4479\-B0FC\-9F4394BE5455]
! in the Java Flight Recorder Command Reference.
.RS
.RE
.TP
.B \f[CB]JFR.stop\f[R] [\f[I]options\f[R]]
! See \f[B]JFR.stop\f[R]
! [https://www.oracle.com/pls/topic/lookup?ctx=en/java/javase/11/tools&id=JFRCR\-GUID\-66CC94C8\-8EDF\-4BB6\-8E7A\-49973025D4D9]
! in the Java Flight Recorder Command Reference.
.RS
.RE
.TP
.B \f[CB]JVMTI.agent_load\f[R] [\f[I]arguments\f[R]]
Loads JVMTI native agent.
.RS
--- 355,644 ----
.PP
Impact: Medium \-\-\- depends on the Java content.
.RE
.TP
.B \f[CB]JFR.check\f[R] [\f[I]options\f[R]]
! Show information about a running flight recording
.RS
+ .PP
+ Impact: Low
+ .PP
+ \f[B]Note:\f[R]
+ .PP
+ The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
+ \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
+ If no parameters are entered, information for all active recordings is
+ shown.
+ .PP
+ \f[I]options\f[R]:
+ .IP \[bu] 2
+ \f[CB]name\f[R]: (Optional) Name of the flight recording.
+ (STRING, no default value)
+ .IP \[bu] 2
+ \f[CB]verbose\f[R]: (Optional) Flag for printing the event settings for
+ the recording (BOOLEAN, false)
.RE
.TP
.B \f[CB]JFR.configure\f[R] [\f[I]options\f[R]]
! Set the parameters for a flight recording
.RS
+ .PP
+ Impact: Low
+ .PP
+ \f[B]Note:\f[R]
+ .PP
+ The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
+ \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
+ If no parameters are entered, the current settings are displayed.
+ .PP
+ \f[I]options\f[R]:
+ .IP \[bu] 2
+ \f[CB]globalbuffercount\f[R]: (Optional) Number of global buffers.
+ This option is a legacy option: change the \f[CB]memorysize\f[R] parameter
+ to alter the number of global buffers.
+ This value cannot be changed once JFR has been initalized.
+ (STRING, default determined by the value for \f[CB]memorysize\f[R])
+ .IP \[bu] 2
+ \f[CB]globalbuffersize\f[R]: (Optional) Size of the global buffers, in
+ bytes.
+ This option is a legacy option: change the \f[CB]memorysize\f[R] parameter
+ to alter the size of the global buffers.
+ This value cannot be changed once JFR has been initalized.
+ (STRING, default determined by the value for \f[CB]memorysize\f[R])
+ .IP \[bu] 2
+ \f[CB]maxchunksize\f[R]: (Optional) Maximum size of an individual data
+ chunk in bytes if one of the following suffixes is not used: \[aq]m\[aq]
+ or \[aq]M\[aq] for megabytes OR \[aq]g\[aq] or \[aq]G\[aq] for
+ gigabytes.
+ This value cannot be changed once JFR has been initialized.
+ (STRING, 12M)
+ .IP \[bu] 2
+ \f[CB]memorysize\f[R]: (Optional) Overall memory size, in bytes if one of
+ the following suffixes is not used: \[aq]m\[aq] or \[aq]M\[aq] for
+ megabytes OR \[aq]g\[aq] or \[aq]G\[aq] for gigabytes.
+ This value cannot be changed once JFR has been initialized.
+ (STRING, 10M)
+ .IP \[bu] 2
+ \f[CB]repositorypath\f[R]: (Optional) Path to the location where
+ recordings are stored until they are written to a permanent file.
+ (STRING, The default location is the temporary directory for the
+ operating system.
+ On Linux operating systems, the temporary directory is \f[CB]/tmp\f[R].
+ On Windwows, the temporary directory is specified by the \f[CB]TMP\f[R]
+ environment variable.)
+ .IP \[bu] 2
+ \f[CB]stackdepth\f[R]: (Optional) Stack depth for stack traces.
+ Setting this value greater than the default of 64 may cause a
+ performance degradation.
+ This value cannot be changed once JFR has been initialized.
+ (LONG, 64)
+ .IP \[bu] 2
+ \f[CB]thread_buffer_size\f[R]: (Optional) Local buffer size for each
+ thread in bytes if one of the following suffixes is not used:
+ \[aq]k\[aq] or \[aq]K\[aq] for kilobytes or \[aq]m\[aq] or \[aq]M\[aq]
+ for megabytes.
+ Overriding this parameter could reduce performance and is not
+ recommended.
+ This value cannot be changed once JFR has been initialized.
+ (STRING, 8k)
+ .IP \[bu] 2
+ \f[CB]samplethreads\f[R]: (Optional) Flag for activating thread sampling.
+ (BOOLEAN, true)
.RE
.TP
.B \f[CB]JFR.dump\f[R] [\f[I]options\f[R]]
! Write data to a file while a flight recording is running
.RS
+ .PP
+ Impact: Low
+ .PP
+ \f[B]Note:\f[R]
+ .PP
+ The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
+ \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
+ No options are required.
+ The recording continues to run after the data is written.
+ .PP
+ \f[I]options\f[R]:
+ .IP \[bu] 2
+ \f[CB]begin\f[R]: (Optional) Specify the time from which recording data
+ will be included in the dump file.
+ The format is specified as local time.
+ (STRING, no default value)
+ .IP \[bu] 2
+ \f[CB]end\f[R]: (Optional) Specify the time to which recording data will
+ be included in the dump file.
+ The format is specified as local time.
+ (STRING, no default value)
+ .RS 2
+ .PP
+ \f[B]Note:\f[R] For both \f[CB]begin\f[R] and \f[CB]end\f[R], the time must
+ be in a format that can be read by java.time.LocalTime::parse(STRING),
+ java.time.LocalDateTime::parse(STRING) or
+ java.time.Instant::parse(STRING).
+ For example, "13:20:15", "2020\-03\-17T09:00:00" or
+ "2020\-03\-17T09:00:00Z".
+ .PP
+ \f[B]Note:\f[R] \f[CB]begin\f[R] and \f[CB]end\f[R] times correspond to the
+ timestamps found within the recorded information in the flight recording
+ data.
+ .PP
+ Another option is to use a time relative to the current time that is
+ specified by a negative integer followed by "s", "m" or "h".
+ For example, "\-12h", "\-15m" or "\-30s"
+ .RE
+ .IP \[bu] 2
+ \f[CB]filename\f[R]: (Optional) Name of the file to which the flight
+ recording data is dumped.
+ If no filename is given, a filename is generated from the PID and the
+ current date.
+ The filename may also be a directory in which case, the filename is
+ generated from the PID and the current date in the specified directory.
+ (STRING, no default value)
+ .IP \[bu] 2
+ \f[CB]maxage\f[R]: (Optional) Length of time for dumping the flight
+ recording data to a file.
+ (INTEGER followed by \[aq]s\[aq] for seconds \[aq]m\[aq] for minutes or
+ \[aq]h\[aq] for hours, no default value)
+ .IP \[bu] 2
+ \f[CB]maxsize\f[R]: (Optional) Maximum size for the amount of data to dump
+ from a flight recording in bytes if one of the following suffixes is not
+ used: \[aq]m\[aq] or \[aq]M\[aq] for megabytes OR \[aq]g\[aq] or
+ \[aq]G\[aq] for gigabytes.
+ (STRING, no default value)
+ .IP \[bu] 2
+ \f[CB]name\f[R]: (Optional) Name of the recording.
+ If no name is given, data from all recordings is dumped.
+ (STRING, no default value)
+ .IP \[bu] 2
+ \f[CB]path\-to\-gc\-root\f[R]: (Optional) Flag for saving the path to
+ garbage collection (GC) roots at the time the recording data is dumped.
+ The path information is useful for finding memory leaks but collecting
+ it can cause the application to pause for a short period of time.
+ Turn on this flag only when you have an application that you suspect has
+ a memory leak.
+ (BOOLEAN, false)
.RE
.TP
.B \f[CB]JFR.start\f[R] [\f[I]options\f[R]]
! Start a flight recording
.RS
+ .PP
+ Impact: Low
+ .PP
+ \f[B]Note:\f[R]
+ .PP
+ The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
+ \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
+ If no parameters are entered, then a recording is started with default
+ values.
+ .PP
+ \f[I]options\f[R]:
+ .IP \[bu] 2
+ \f[CB]delay\f[R]: (Optional) Length of time to wait before starting to
+ record (INTEGER followed by \[aq]s\[aq] for seconds \[aq]m\[aq] for
+ minutes or \[aq]h\[aq] for hours, 0s)
+ .IP \[bu] 2
+ \f[CB]disk\f[R]: (Optional) Flag for also writing the data to disk while
+ recording (BOOLEAN, true)
+ .IP \[bu] 2
+ \f[CB]dumponexit\f[R]: (Optional) Flag for writing the recording to disk
+ when the Java Virtual Machine (JVM) shuts down.
+ If set to \[aq]true\[aq] and no value is given for \f[CB]filename\f[R],
+ the recording is written to a file in the directory where the process
+ was started.
+ The file name is a system\-generated name that contains the process ID,
+ the recording ID and the current time stamp.
+ (For example: \f[CB]id\-1\-2019_12_12_10_41.jfr\f[R]) (BOOLEAN, false)
+ .IP \[bu] 2
+ \f[CB]duration\f[R]: (Optional) Length of time to record.
+ Note that \f[CB]0s\f[R] means forever (INTEGER followed by \[aq]s\[aq] for
+ seconds \[aq]m\[aq] for minutes or \[aq]h\[aq] for hours, 0s)
+ .IP \[bu] 2
+ \f[CB]filename\f[R]: (Optional) Name of the file to which the flight
+ recording data is written when the recording is stopped.
+ If no filename is given, a filename is generated from the PID and the
+ current date and is placed in the directory where the process was
+ started.
+ The filename may also be a directory in which case, the filename is
+ generated from the PID and the current date in the specified directory.
+ (STRING, no default value)
+ .IP \[bu] 2
+ \f[CB]maxage\f[R]: (Optional) Maximum time to keep the recorded data on
+ disk.
+ This parameter is valid only when the \f[CB]disk\f[R] parameter is set to
+ \f[CB]true\f[R].
+ Note \f[CB]0s\f[R] means forever.
+ (INTEGER followed by \[aq]s\[aq] for seconds \[aq]m\[aq] for minutes or
+ \[aq]h\[aq] for hours, 0s)
+ .IP \[bu] 2
+ \f[CB]maxsize\f[R]: (Optional) Maximum size of the data to keep on disk in
+ bytes if one of the following suffixes is not used: \[aq]m\[aq] or
+ \[aq]M\[aq] for megabytes OR \[aq]g\[aq] or \[aq]G\[aq] for gigabytes.
+ This parameter is valid only when the \f[CB]disk\f[R] parameter is set to
+ \[aq]true\[aq].
+ The value must not be less than the value for the \f[CB]maxchunksize\f[R]
+ parameter set with the \f[CB]JFR.configure\f[R] command.
+ (STRING, 0 (no maximum size))
+ .IP \[bu] 2
+ \f[CB]name\f[R]: (Optional) Name of the recording.
+ If no name is provided, a name is generated.
+ Make note of the generated name that is shown in the response to the
+ command so that you can use it with other commands.
+ (STRING, system\-generated default name)
+ .IP \[bu] 2
+ \f[CB]path\-to\-gc\-root\f[R]: (Optional) Flag for saving the path to
+ garbage collection (GC) roots at the end of a recording.
+ The path information is useful for finding memory leaks but collecting
+ it is time consuming.
+ Turn on this flag only when you have an application that you suspect has
+ a memory leak.
+ If the \f[CB]settings\f[R] parameter is set to \[aq]profile\[aq], then the
+ information collected includes the stack trace from where the potential
+ leaking object was allocated.
+ (BOOLEAN, false)
+ .IP \[bu] 2
+ \f[CB]settings\f[R]: (Optional) Name of the settings file that identifies
+ which events to record.
+ To specify more than one file, separate the names with a comma
+ (\[aq],\[aq]).
+ Include the path if the file is not in \f[CB]JAVA\-HOME\f[R]/lib/jfr.
+ The following profiles are included with the JDK in the
+ \f[CB]JAVA\-HOME\f[R]/lib/jfr directory: \[aq]default.jfc\[aq]: collects a
+ predefined set of information with low overhead, so it has minimal
+ impact on performance and can be used with recordings that run
+ continuously; \[aq]profile.jfc\[aq]: Provides more data than the
+ \[aq]default.jfc\[aq] profile, but with more overhead and impact on
+ performance.
+ Use this configuration for short periods of time when more information
+ is needed.
+ Use \f[CB]none\f[R] to start a recording without a predefined
+ configuration file.
+ (STRING, \f[CB]JAVA\-HOME\f[R]/lib/jfr/default.jfc)
.RE
.TP
.B \f[CB]JFR.stop\f[R] [\f[I]options\f[R]]
! Stop a flight recording
.RS
+ .PP
+ Impact: Low
+ .PP
+ \f[B]Note:\f[R]
+ .PP
+ The \f[I]options\f[R] must be specified using either \f[I]key\f[R] or
+ \f[I]key\f[R]\f[CB]=\f[R]\f[I]value\f[R] syntax.
+ If no parameters are entered, then no recording is stopped.
+ .PP
+ \f[I]options\f[R]:
+ .IP \[bu] 2
+ \f[CB]filename\f[R]: (Optional) Name of the file to which the recording is
+ written when the recording is stopped.
+ If no path is provided, the data from the recording is discarded.
+ (STRING, no default value)
+ .IP \[bu] 2
+ \f[CB]name\f[R]: (Optional) Name of the recording (STRING, no default
+ value)
.RE
.TP
.B \f[CB]JVMTI.agent_load\f[R] [\f[I]arguments\f[R]]
Loads JVMTI native agent.
.RS
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