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 theps
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 inhprof
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.