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JMAP

Section: JDK Commands (1)
Updated: 2023
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NAME

jmap- print details of a specified process

SYNOPSIS

B]Note:R] This command is experimental and unsupported.

V]jmapR] [I]optionsR]] I]pidR]

I]optionsR]: This represents the V]jmapR] comman-line options. See B]Options for the jmap CommandR].
I]pidR]: The process ID for which the information specified by the I]optionsR] is to be printed. The process must be a Java process. To get a list of Java processes running on a machine, use either the V]psR] command or, if the JVM processes are not running in a separate docker instance, the B]jpsR] command.

DESCRIPTION

The V]jmapR] command prints details of a specified running process.

B]Note:R]

This command is unsupported and might not be available in future releases of the JDK. On Windows Systems where the V]dbgeng.dllR] file isn[aq]t present, the Debugging Tools for Windows must be installed to make these tools work. The V]PATHR] environment variable should contain the location of the V]jvm.dllR] file that[aq]s used by the target process or the location from which the core dump file was produced.

OPTIONS FOR THE JMAP COMMAND

V-clstatsR] I]pidR]

Connects to a running process and prints class loader statistics of Java heap.

V-finalizerinfoR] I]pidR]

Connects to a running process and prints information on objects awaiting finalization.

V-histoR][V]:liveR]] I]pidR]

Connects to a running process and prints a histogram of the Java object heap. If the V]liveR] suboption is specified, it then counts only live objects.

V-dump:R]I]dump_optionsR] I]pidR]

Connects to a running process and dumps the Java heap. The I]dump_optionsR] include:

[bu]: V]liveR]- When specified, dumps only the live objects; if not specified, then dumps all objects in the heap.
[bu]: V]format=bR]- Dumps the Java heap in V]hprofR] binary format
[bu]: V]file=R]I]filenameR]- Dumps the heap to I]filenameR]

Example: V]jmap-dump:live,format=b,file=heap.binR] I]pidR]