JHSDB(1)                         JDK Commands                         JHSDB(1)

NAME
       jhsdb - attach to a Java process or launch a postmortem debugger to
       analyze the content of a core dump from a crashed Java Virtual Machine
       (JVM)

SYNOPSIS
       jhsdb clhsdb [--pid pid | --exe executable --core coredump]

       jhsdb hsdb [--pid pid | --exe executable --core coredump]

       jhsdb debugd (--pid pid | --exe executable --core coredump) [options]

       jhsdb jstack (--pid pid | --exe executable --core coredump | --connect
       [server-id@]debugd-host) [options]

       jhsdb jmap (--pid pid | --exe executable --core coredump | --connect
       [server-id@]debugd-host) [options]

       jhsdb jinfo (--pid pid | --exe executable --core coredump | --connect
       [server-id@]debugd-host) [options]

       jhsdb jsnap (--pid pid | --exe executable --core coredump | --connect
       [server-id@]debugd-host) [options]

       pid    The process ID to which the jhsdb tool should attach.  The
              process must be a Java process.  To get a list of Java processes
              running on a machine, use the ps command or, if the JVM
              processes are not running in a separate docker instance, the jps
              command.

       executable
              The Java executable file from which the core dump was produced.

       coredump
              The core file to which the jhsdb tool should attach.

       [server-id@]debugd-host
              An optional server ID and the address of the remote debug server
              (debugd).

       options
              The command-line options for a jhsdb mode.  See Options for the
              debugd Mode, Options for the jstack Mode, Options for the jmap
              Mode, Options for the jinfo Mode, and Options for the jsnap
              Mode.

       Note:

       Either the pid or the pair of executable and core files or the
       [server-id@]debugd-host must be provided for debugd, jstack, jmap,
       jinfo and jsnap modes.

DESCRIPTION
       You can use the jhsdb tool to attach to a Java process or to launch a
       postmortem debugger to analyze the content of a core-dump from a
       crashed Java Virtual Machine (JVM).  This command is experimental and
       unsupported.

       Note:

       Attaching the jhsdb tool to a live process will cause the process to
       hang and the process will probably crash when the debugger detaches.

       The jhsdb tool can be launched in any one of the following modes:

       jhsdb clhsdb
              Starts the interactive command-line debugger.

       jhsdb hsdb
              Starts the interactive GUI debugger.

       jhsdb debugd
              Starts the remote debug server.

       jhsdb jstack
              Prints stack and locks information.

       jhsdb jmap
              Prints heap information.

       jhsdb jinfo
              Prints basic JVM information.

       jhsdb jsnap
              Prints performance counter information.

       jhsdb command --help
              Displays the options available for the command.

OPTIONS FOR THE DEBUGD MODE
       --serverid server-id
              An optional unique ID for this debug server.  This is required
              if multiple debug servers are run on the same machine.

       --rmiport port
              Sets the port number to which the RMI connector is bound.  If
              not specified a random available port is used.

       --registryport port
              Sets the RMI registry port.  This option overrides the system
              property 'sun.jvm.hotspot.rmi.port'.  If not specified, the
              system property is used.  If the system property is not set, the
              default port 1099 is used.

       --hostname hostname
              Sets the hostname the RMI connector is bound.  The value could
              be a hostname or an IPv4/IPv6 address.  This option overrides
              the system property 'java.rmi.server.hostname'.  If not
              specified, the system property is used.  If the system property
              is not set, a system hostname is used.

OPTIONS FOR THE JINFO MODE
       --flags
              Prints the VM flags.

       --sysprops
              Prints the Java system properties.

       no option
              Prints the VM flags and the Java system properties.

OPTIONS FOR THE JMAP MODE
       no option
              Prints the same information as Solaris pmap.

       --heap Prints the java heap summary.

       --binaryheap
              Dumps the java heap in hprof binary format.

       --dumpfile name
              The name of the dumpfile.

       --histo
              Prints the histogram of java object heap.

       --clstats
              Prints the class loader statistics.

       --finalizerinfo
              Prints the information on objects awaiting finalization.

OPTIONS FOR THE JSTACK MODE
       --locks
              Prints the java.util.concurrent locks information.

       --mixed
              Attempts to print both java and native frames if the platform
              allows it.

OPTIONS FOR THE JSNAP MODE
       --all  Prints all performance counters.

JDK 17                               2021                             JHSDB(1)