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.TH "JHSDB" "1" "2018" "JDK 13" "JDK Commands"
.hy
.SH NAME
.PP
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)
.SH SYNOPSIS
.PP
\f[CB]jhsdb\f[R] \f[CB]clhsdb\f[R] [\f[CB]\-\-pid\f[R] \f[I]pid\f[R] |
\f[CB]\-\-exe\f[R] \f[I]executable\f[R] \f[CB]\-\-core\f[R]
\f[I]coredump\f[R]]
.PP
\f[CB]jhsdb\f[R] \f[CB]debugd\f[R] [\f[I]options\f[R]] (\f[I]pid\f[R] |
\f[I]executable\f[R] \f[I]coredump\f[R]) [\f[I]server\-id\f[R]]
.PP
\f[CB]jhsdb\f[R] \f[CB]hsdb\f[R] [\f[CB]\-\-pid\f[R] \f[I]pid\f[R] |
\f[CB]\-\-exe\f[R] \f[I]executable\f[R] \f[CB]\-\-core\f[R]
\f[I]coredump\f[R]]
.PP
\f[CB]jhsdb\f[R] \f[CB]jstack\f[R] [\f[CB]\-\-pid\f[R] \f[I]pid\f[R] |
\f[CB]\-\-exe\f[R] \f[I]executable\f[R] \f[CB]\-\-core\f[R]
\f[I]coredump\f[R]] [\f[I]options\f[R]]
.PP
\f[CB]jhsdb\f[R] \f[CB]jmap\f[R] [\f[CB]\-\-pid\f[R] \f[I]pid\f[R] |
\f[CB]\-\-exe\f[R] \f[I]executable\f[R] \f[CB]\-\-core\f[R]
\f[I]coredump\f[R]] [\f[I]options\f[R]]
.PP
\f[CB]jhsdb\f[R] \f[CB]jinfo\f[R] [\f[CB]\-\-pid\f[R] \f[I]pid\f[R] |
\f[CB]\-\-exe\f[R] \f[I]executable\f[R] \f[CB]\-\-core\f[R]
\f[I]coredump\f[R]] [\f[I]options\f[R]]
.PP
\f[CB]jhsdb\f[R] \f[CB]jsnap\f[R] [\f[I]options\f[R]] [\f[CB]\-\-pid\f[R]
\f[I]pid\f[R] | \f[CB]\-\-exe\f[R] \f[I]executable\f[R] \f[CB]\-\-core\f[R]
\f[I]coredump\f[R]]
.TP
.B \f[I]pid\f[R]
The process ID to which the \f[CB]jhsdb\f[R] tool should attach.
The process must be a Java process.
To get a list of Java processes running on a machine, use the
\f[CB]ps\f[R] command or, if the JVM processes are not running in a
separate docker instance, the \f[B]jps\f[R] command.
.RS
.PP
\f[B]Note:\f[R] JDK 10 has added support for using the Attach API when
attaching to Java processes running in a separate docker process.
However, the \f[CB]jps\f[R] command 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 \f[CB]ps\f[R] to look up
the PID of the JVM.
.RE
.TP
.B \f[I]server\-id\f[R]
An optional unique ID to use when multiple debug servers are running on
the same remote host.
.RS
.RE
.TP
.B \f[I]executable\f[R]
The Java executable file from which the core dump was produced.
.RS
.RE
.TP
.B \f[I]coredump\f[R]
The core file to which the \f[CB]jhsdb\f[R] tool should attach.
.RS
.RE
.TP
.B \f[I]options\f[R]
The command\-line options for a \f[CB]jhsdb\f[R] mode.
See \f[B]Common Options for jhsdb Modes\f[R], \f[B]Options for the debugd
Mode\f[R], \f[B]Options for the jinfo Mode\f[R], \f[B]Options for the jmap
Mode\f[R], \f[B]Options for the jmap Mode\f[R], \f[B]Options for the
jstack Mode\f[R], and \f[B]Options for the jsnap Mode\f[R].
.RS
.RE
.PP
\f[B]Note:\f[R]
.PP
Either the \f[I]pid\f[R] or the pair of \f[I]executable\f[R] and
\f[I]core\f[R] files must be provided.
.SH DESCRIPTION
.PP
You can use the \f[CB]jhsdb\f[R] 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.
.PP
\f[B]Note:\f[R]
.PP
Attaching the \f[CB]jhsdb\f[R] tool to a live process will cause the
process to hang and the process will probably crash when the debugger
detaches.
.PP
The \f[CB]jhsdb\f[R] tool can be launched in any one of the following
modes:
.TP
.B \f[CB]jhsdb\ clhsdb\f[R]
Starts the interactive command\-line debugger.
.RS
.RE
.TP
.B \f[CB]jhsdb\ debugd\f[R]
Starts the remote debug server.
.RS
.RE
.TP
.B \f[CB]jhsdb\ hsdb\f[R]
Starts the interactive GUI debugger.
.RS
.RE
.TP
.B \f[CB]jhsdb\ jstack\f[R]
Prints stack and locks information.
.RS
.RE
.TP
.B \f[CB]jhsdb\ jmap\f[R]
Prints heap information.
.RS
.RE
.TP
.B \f[CB]jhsdb\ jinfo\f[R]
Prints basic JVM information.
.RS
.RE
.TP
.B \f[CB]jhsdb\ jsnap\f[R]
Prints performance counter information.
.RS
.RE
.SH COMMON OPTIONS FOR JHSDB MODES
.PP
In addition to any required \f[CB]jstack\f[R], \f[CB]jmap\f[R],
\f[CB]jinfo\f[R] or \f[CB]jsnap\f[R] mode specific options, the
\f[CB]pid\f[R], \f[CB]exe\f[R], or \f[CB]core\f[R] options must be provided
for all modes.
The following options are available for all modes.
.TP
.B \f[CB]\-\-pid\f[R]
The process ID of the hanging process.
.RS
.RE
.TP
.B \f[CB]\-\-exe\f[R]
The executable file name.
.RS
.RE
.TP
.B \f[CB]\-\-core\f[R]
The core dump file name.
.RS
.RE
.TP
.B \f[CB]\-\-help\f[R]
Displays the options available for the command.
.RS
.RE
.SH OPTIONS FOR THE DEBUGD MODE
.TP
.B \f[I]server\-id\f[R]
An optional unique ID for this debug server.
This is required if multiple debug servers are run on the same machine.
.RS
.RE
.SH OPTIONS FOR THE JINFO MODE
.PP
Without specified options, the \f[CB]jhsdb\ jinfo\f[R] prints both flags
and properties.
.TP
.B \f[CB]\-\-flags\f[R]
Prints the VM flags.
.RS
.RE
.TP
.B \f[CB]\-\-sysprops\f[R]
Prints the Java system properties.
.RS
.RE
.TP
.B no option
Prints the VM flags and the Java system properties.
.RS
.RE
.SH OPTIONS FOR THE JMAP MODE
.PP
In addition to the following mode specific options, the \f[CB]pid\f[R],
\f[CB]exe\f[R], or \f[CB]core\f[R] options described in \f[B]Common Options
for jhsdb Modes\f[R] must be provided.
.TP
.B no option
Prints the same information as Solaris \f[CB]pmap\f[R].
.RS
.RE
.TP
.B \f[CB]\-\-heap\f[R]
Prints the \f[CB]java\f[R] heap summary.
.RS
.RE
.TP
.B \f[CB]\-\-binaryheap\f[R]
Dumps the \f[CB]java\f[R] heap in \f[CB]hprof\f[R] binary format.
.RS
.RE
.TP
.B \f[CB]\-\-dumpfile\f[R]
Prints the name of the dumpfile.
.RS
.RE
.TP
.B \f[CB]\-\-histo\f[R]
Prints the histogram of \f[CB]java\f[R] object heap.
.RS
.RE
.TP
.B \f[CB]\-\-clstats\f[R]
Prints the class loader statistics.
.RS
.RE
.TP
.B \f[CB]\-\-finalizerinfo\f[R]
Prints the information on objects awaiting finalization.
.RS
.RE
.SH OPTIONS FOR THE JSTACK MODE
.PP
In addition to the following mode specific options, the \f[CB]pid\f[R],
\f[CB]exe\f[R], or \f[CB]core\f[R] options described in \f[B]Common Options
for jhsdb Modes\f[R] must be provided.
.TP
.B \f[CB]\-\-locks\f[R]
Prints the \f[CB]java.util.concurrent\f[R] locks information.
.RS
.RE
.TP
.B \f[CB]\-\-mixed\f[R]
Attempts to print both \f[CB]java\f[R] and native frames if the platform
allows it.
.RS
.RE
.SH OPTIONS FOR THE JSNAP MODE
.PP
In addition to the following mode specific option, the \f[CB]pid\f[R],
\f[CB]exe\f[R], or \f[CB]core\f[R] options described in \f[B]Common Options
for jhsdb Modes\f[R] must be provided.
.TP
.B \f[CB]\-\-all\f[R]
Prints all performance counters.
.RS
.RE