Usage: jmap -clstats to connect to running process and print class loader statistics jmap -finalizerinfo to connect to running process and print information on objects awaiting finalization jmap -histo[:[]] to connect to running process and print histogram of java object heap jmap -dump: to connect to running process and dump java heap jmap -? -h --help to print this help message dump-options: live dump only live objects (takes precedence if both "live" and "all" are specified) all dump all objects in the heap (default if one of "live" or "all" is not specified) format=b binary format file= dump heap to gz= If specified, the heap dump is written in gzipped format using the given compression level. 1 (recommended) is the fastest, 9 the strongest compression. Example: jmap -dump:live,format=b,file=heap.bin histo-options: live count only live objects (takes precedence if both "live" and "all" are specified) all count all objects in the heap (default if one of "live" or "all" is not specified) file= dump data to parallel= Number of parallel threads to use for heap inspection: 0 (the default) means let the VM determine the number of threads to use 1 means use one thread (disable parallelism). For any other value the VM will try to use the specified number of threads, but might use fewer. Example: jmap -histo:live,file=/tmp/histo.data