You use the
jmap command to print details of a specified process. This command is experimental and unsupported.
jmap [options] pid
This represents the
jmap command-line options. See Options for the jmap Command.
The process ID for which the information specified by the
options 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
ps command or, if the JVM processes are not running in a separate docker instance, the jps command.
Note:JDK 10 has added support for using the Attach API when attaching to Java processes running in a separate docker process. However, the
jpscommand will not list the JVM processes that are running in a separate docker instance. If you are trying to connect a Linux host with a Virtual Machine that is in a docker container, you must use tools such as
psto look up the PID of the JVM.
jmap command prints details of a specified running process.
This command is unsupported and might not be available in future releases of the JDK. On Windows Systems where the
dbgeng.dll file isn’t present, the Debugging Tools for Windows must be installed to make these tools work. The
PATH environment variable should contain the location of the
jvm.dll file that’s used by the target process or the location from which the core dump file was produced.
Options for the jmap Command
Connects to a running process and prints class loader statistics of Java heap.
Connects to a running process and prints information on objects awaiting finalization.
Connects to a running process and prints a histogram of the Java object heap. If the
live suboption is specified, it then counts only live objects.
-dump:dump options pid
Connects to a running process and dumps the Java heap. The
dump options include:
live — When specified, dumps only the live objects; if not specified, then dumps all objects in the heap.
format=b — Dumps the Java heap,. in
hprof binary format
file=filename — Dumps the heap to
jmap -dump:live,format=b,file=heap.bin pid