759 lines
23 KiB
Groff
759 lines
23 KiB
Groff
'\" t
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.\" Copyright (c) 2004, 2015, Oracle and/or its affiliates. All rights reserved.
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.\"
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.\" Title: jstat
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.\" Language: English
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.\" Date: 03 March 2015
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.\" SectDesc: Monitoring Tools
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.\" Software: JDK 8
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.\" Arch: generic
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.\" Part Number: E38209-04
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.\" Doc ID: JSSOR
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.\"
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.if n .pl 99999
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.TH "jstat" "1" "03 March 2015" "JDK 8" "Monitoring Tools"
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.\" -----------------------------------------------------------------
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.\" * Define some portability stuff
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.\" -----------------------------------------------------------------
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.\" http://bugs.debian.org/507673
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.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.ie \n(.g .ds Aq \(aq
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.el .ds Aq '
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.\" -----------------------------------------------------------------
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.\" * set default formatting
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.\" -----------------------------------------------------------------
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.\" disable hyphenation
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.nh
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.\" disable justification (adjust text to left margin only)
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.ad l
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.\" -----------------------------------------------------------------
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.\" * MAIN CONTENT STARTS HERE *
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.\" -----------------------------------------------------------------
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.SH "NAME"
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jstat \- Monitors Java Virtual Machine (JVM) statistics\&. This command is experimental and unsupported\&.
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.SH "SYNOPSIS"
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.sp
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.if n \{\
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.RS 4
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.\}
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.nf
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\fBjstat\fR [ \fIgeneralOption\fR | \fIoutputOptions vmid\fR [ \fIinterval\fR[s|ms] [ \fIcount \fR] ]
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.fi
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.if n \{\
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.RE
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.\}
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.PP
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\fIgeneralOption\fR
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.RS 4
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A single general command\-line option
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\fB\-help\fR
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or
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\fB\-options\fR\&. See General Options\&.
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.RE
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.PP
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\fIoutputOptions\fR
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.RS 4
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One or more output options that consist of a single
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\fBstatOption\fR, plus any of the
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\fB\-t\fR,
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\fB\-h\fR, and
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\fB\-J\fR
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options\&. See Output Options\&.
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.RE
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.PP
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\fIvmid\fR
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.RS 4
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Virtual machine identifier, which is a string that indicates the target JVM\&. The general syntax is the following:
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.sp
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.if n \{\
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.RS 4
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.\}
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.nf
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\fB[protocol:][//]lvmid[@hostname[:port]/servername]\fR
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.fi
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.if n \{\
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.RE
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.\}
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The syntax of the
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\fBvmid\fR
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string corresponds to the syntax of a URI\&. The
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\fBvmid\fR
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string can vary from a simple integer that represents a local JVM to a more complex construction that specifies a communications protocol, port number, and other implementation\-specific values\&. See Virtual Machine Identifier\&.
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.RE
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.PP
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\fIinterval\fR [s|ms]
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.RS 4
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Sampling interval in the specified units, seconds (s) or milliseconds (ms)\&. Default units are milliseconds\&. Must be a positive integer\&. When specified, the
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\fBjstat\fR
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command produces its output at each interval\&.
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.RE
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.PP
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\fIcount\fR
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.RS 4
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Number of samples to display\&. The default value is infinity which causes the
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\fBjstat\fR
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command to display statistics until the target JVM terminates or the
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\fBjstat\fR
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command is terminated\&. This value must be a positive integer\&.
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.RE
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.SH "DESCRIPTION"
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.PP
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The
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\fBjstat\fR
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command displays performance statistics for an instrumented Java HotSpot VM\&. The target JVM is identified by its virtual machine identifier, or
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\fBvmid\fR
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option\&.
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.SH "VIRTUAL MACHINE IDENTIFIER"
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.PP
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The syntax of the
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\fBvmid\fR
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string corresponds to the syntax of a URI:
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.sp
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.if n \{\
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.RS 4
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.\}
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.nf
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\fB[protocol:][//]lvmid[@hostname[:port]/servername]\fR
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.fi
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.if n \{\
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.RE
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.\}
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.PP
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\fIprotocol\fR
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.RS 4
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The communications protocol\&. If the
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\fIprotocol\fR
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value is omitted and a host name is not specified, then the default protocol is a platform\-specific optimized local protocol\&. If the
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\fIprotocol\fR
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value is omitted and a host name is specified, then the default protocol is
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\fBrmi\fR\&.
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.RE
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.PP
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\fIlvmid\fR
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.RS 4
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The local virtual machine identifier for the target JVM\&. The
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\fBlvmid\fR
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is a platform\-specific value that uniquely identifies a JVM on a system\&. The
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\fBlvmid\fR
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is the only required component of a virtual machine identifier\&. The
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\fBlvmid\fR
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is typically, but not necessarily, the operating system\*(Aqs process identifier for the target JVM process\&. You can use the
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\fBjps\fR
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command to determine the
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\fBlvmid\fR\&. Also, you can determine the
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\fBlvmid\fR
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on Solaris, Linux, and OS X platforms with the
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\fBps\fR
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command, and on Windows with the Windows Task Manager\&.
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.RE
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.PP
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\fIhostname\fR
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.RS 4
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A hostname or IP address that indicates the target host\&. If the
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\fIhostname\fR
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value is omitted, then the target host is the local host\&.
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.RE
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.PP
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\fIport\fR
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.RS 4
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The default port for communicating with the remote server\&. If the
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\fIhostname\fR
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value is omitted or the
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\fIprotocol\fR
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value specifies an optimized, local protocol, then the
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\fIport\fR
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value is ignored\&. Otherwise, treatment of the
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\fBport\fR
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parameter is implementation\-specific\&. For the default
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\fBrmi\fR
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protocol, the port value indicates the port number for the rmiregistry on the remote host\&. If the
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\fIport\fR
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value is omitted and the
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\fIprotocol\fR
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value indicates
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\fBrmi\fR, then the default rmiregistry port (1099) is used\&.
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.RE
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.PP
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\fIservername\fR
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.RS 4
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The treatment of the
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\fBservername\fR
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parameter depends on implementation\&. For the optimized local protocol, this field is ignored\&. For the
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\fBrmi\fR
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protocol, it represents the name of the RMI remote object on the remote host\&.
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.RE
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.SH "OPTIONS"
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.PP
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The
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\fBjstat\fR
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command supports two types of options, general options and output options\&. General options cause the
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\fBjstat\fR
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command to display simple usage and version information\&. Output options determine the content and format of the statistical output\&.
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.PP
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All options and their functionality are subject to change or removal in future releases\&.
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.SS "General Options"
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.PP
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If you specify one of the general options, then you cannot specify any other option or parameter\&.
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.PP
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\-help
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.RS 4
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Displays a help message\&.
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.RE
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.PP
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\-options
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.RS 4
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Displays a list of static options\&. See Output Options\&.
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.RE
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.SS "Output Options"
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.PP
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If you do not specify a general option, then you can specify output options\&. Output options determine the content and format of the
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\fBjstat\fR
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command\*(Aqs output, and consist of a single
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\fBstatOption\fR, plus any of the other output options (\fB\-h\fR,
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\fB\-t\fR, and
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\fB\-J\fR)\&. The
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\fBstatOption\fR
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must come first\&.
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.PP
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Output is formatted as a table, with columns that are separated by spaces\&. A header row with titles describes the columns\&. Use the
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\fB\-h\fR
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option to set the frequency at which the header is displayed\&. Column header names are consistent among the different options\&. In general, if two options provide a column with the same name, then the data source for the two columns is the same\&.
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.PP
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Use the
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\fB\-t\fR
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option to display a time stamp column, labeled Timestamp as the first column of output\&. The Timestamp column contains the elapsed time, in seconds, since the target JVM started\&. The resolution of the time stamp is dependent on various factors and is subject to variation due to delayed thread scheduling on heavily loaded systems\&.
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.PP
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Use the interval and count parameters to determine how frequently and how many times, respectively, the
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\fBjstat\fR
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command displays its output\&.
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.PP
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\fBNote:\fR
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Do not to write scripts to parse the
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\fBjstat\fR
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command\*(Aqs output because the format might change in future releases\&. If you write scripts that parse
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\fBjstat\fR
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command output, then expect to modify them for future releases of this tool\&.
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.PP
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\-\fIstatOption\fR
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.RS 4
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Determines the statistics information the
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\fBjstat\fR
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command displays\&. The following lists the available options\&. Use the
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\fB\-options\fR
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general option to display the list of options for a particular platform installation\&. See Stat Options and Output\&.
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.sp
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\fBclass\fR: Displays statistics about the behavior of the class loader\&.
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.sp
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\fBcompiler\fR: Displays statistics about the behavior of the Java HotSpot VM Just\-in\-Time compiler\&.
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.sp
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\fBgc\fR: Displays statistics about the behavior of the garbage collected heap\&.
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.sp
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\fBgccapacity\fR: Displays statistics about the capacities of the generations and their corresponding spaces\&.
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.sp
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\fBgccause\fR: Displays a summary about garbage collection statistics (same as
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\fB\-gcutil\fR), with the cause of the last and current (when applicable) garbage collection events\&.
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.sp
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\fBgcnew\fR: Displays statistics of the behavior of the new generation\&.
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.sp
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\fBgcnewcapacity\fR: Displays statistics about the sizes of the new generations and its corresponding spaces\&.
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.sp
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\fBgcold\fR: Displays statistics about the behavior of the old generation and metaspace statistics\&.
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.sp
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\fBgcoldcapacity\fR: Displays statistics about the sizes of the old generation\&.
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.sp
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\fBgcmetacapacity\fR: Displays statistics about the sizes of the metaspace\&.
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.sp
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\fBgcutil\fR: Displays a summary about garbage collection statistics\&.
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.sp
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\fBprintcompilation\fR: Displays Java HotSpot VM compilation method statistics\&.
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.RE
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.PP
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\-h \fIn\fR
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.RS 4
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Displays a column header every
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\fIn\fR
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samples (output rows), where
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\fIn\fR
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is a positive integer\&. Default value is 0, which displays the column header the first row of data\&.
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.RE
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.PP
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\-t
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.RS 4
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Displays a timestamp column as the first column of output\&. The time stamp is the time since the start time of the target JVM\&.
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.RE
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.PP
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\-J\fIjavaOption\fR
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.RS 4
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Passes
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\fBjavaOption\fR
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to the Java application launcher\&. For example,
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\fB\-J\-Xms48m\fR
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sets the startup memory to 48 MB\&. For a complete list of options, see
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java(1)\&.
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.RE
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.SS "Stat Options and Output"
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.PP
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The following information summarizes the columns that the
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\fBjstat\fR
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command outputs for each
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\fIstatOption\fR\&.
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.PP
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\-class \fIoption\fR
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.RS 4
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Class loader statistics\&.
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.sp
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\fBLoaded\fR: Number of classes loaded\&.
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.sp
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\fBBytes\fR: Number of kBs loaded\&.
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.sp
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\fBUnloaded\fR: Number of classes unloaded\&.
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.sp
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\fBBytes\fR: Number of Kbytes unloaded\&.
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.sp
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\fBTime\fR: Time spent performing class loading and unloading operations\&.
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.RE
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.PP
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\-compiler \fIoption\fR
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.RS 4
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Java HotSpot VM Just\-in\-Time compiler statistics\&.
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.sp
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\fBCompiled\fR: Number of compilation tasks performed\&.
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.sp
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\fBFailed\fR: Number of compilations tasks failed\&.
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.sp
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\fBInvalid\fR: Number of compilation tasks that were invalidated\&.
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.sp
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\fBTime\fR: Time spent performing compilation tasks\&.
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.sp
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\fBFailedType\fR: Compile type of the last failed compilation\&.
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.sp
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\fBFailedMethod\fR: Class name and method of the last failed compilation\&.
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.RE
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.PP
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\-gc \fIoption\fR
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.RS 4
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Garbage\-collected heap statistics\&.
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.sp
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\fBS0C\fR: Current survivor space 0 capacity (kB)\&.
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.sp
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\fBS1C\fR: Current survivor space 1 capacity (kB)\&.
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.sp
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\fBS0U\fR: Survivor space 0 utilization (kB)\&.
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.sp
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\fBS1U\fR: Survivor space 1 utilization (kB)\&.
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.sp
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\fBEC\fR: Current eden space capacity (kB)\&.
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.sp
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\fBEU\fR: Eden space utilization (kB)\&.
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.sp
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\fBOC\fR: Current old space capacity (kB)\&.
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.sp
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\fBOU\fR: Old space utilization (kB)\&.
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.sp
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\fBMC\fR: Metaspace capacity (kB)\&.
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.sp
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\fBMU\fR: Metacspace utilization (kB)\&.
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.sp
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\fBCCSC\fR: Compressed class space capacity (kB)\&.
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.sp
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\fBCCSU\fR: Compressed class space used (kB)\&.
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.sp
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\fBYGC\fR: Number of young generation garbage collection events\&.
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.sp
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\fBYGCT\fR: Young generation garbage collection time\&.
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.sp
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\fBFGC\fR: Number of full GC events\&.
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.sp
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\fBFGCT\fR: Full garbage collection time\&.
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.sp
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\fBGCT\fR: Total garbage collection time\&.
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.RE
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.PP
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\-gccapacity \fIoption\fR
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.RS 4
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Memory pool generation and space capacities\&.
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.sp
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\fBNGCMN\fR: Minimum new generation capacity (kB)\&.
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.sp
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\fBNGCMX\fR: Maximum new generation capacity (kB)\&.
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.sp
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\fBNGC\fR: Current new generation capacity (kB)\&.
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.sp
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\fBS0C\fR: Current survivor space 0 capacity (kB)\&.
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.sp
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\fBS1C\fR: Current survivor space 1 capacity (kB)\&.
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.sp
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\fBEC\fR: Current eden space capacity (kB)\&.
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.sp
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\fBOGCMN\fR: Minimum old generation capacity (kB)\&.
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.sp
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\fBOGCMX\fR: Maximum old generation capacity (kB)\&.
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.sp
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\fBOGC\fR: Current old generation capacity (kB)\&.
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.sp
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|
\fBOC\fR: Current old space capacity (kB)\&.
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.sp
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\fBMCMN\fR: Minimum metaspace capacity (kB)\&.
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.sp
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\fBMCMX\fR: Maximum metaspace capacity (kB)\&.
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.sp
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|
\fBMC\fR: Metaspace capacity (kB)\&.
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.sp
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|
\fBCCSMN\fR: Compressed class space minimum capacity (kB)\&.
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.sp
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|
\fBCCSMX\fR: Compressed class space maximum capacity (kB)\&.
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.sp
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\fBCCSC\fR: Compressed class space capacity (kB)\&.
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.sp
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|
\fBYGC\fR: Number of young generation GC events\&.
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.sp
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\fBFGC\fR: Number of full GC events\&.
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.RE
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.PP
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\-gccause \fIoption\fR
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.RS 4
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This option displays the same summary of garbage collection statistics as the
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\fB\-gcutil\fR
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option, but includes the causes of the last garbage collection event and (when applicable) the current garbage collection event\&. In addition to the columns listed for
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\fB\-gcutil\fR, this option adds the following columns\&.
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.sp
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|
\fBLGCC\fR: Cause of last garbage collection
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.sp
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\fBGCC\fR: Cause of current garbage collection
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.RE
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.PP
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\-gcnew \fIoption\fR
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.RS 4
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New generation statistics\&.
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.sp
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\fBS0C\fR: Current survivor space 0 capacity (kB)\&.
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.sp
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\fBS1C\fR: Current survivor space 1 capacity (kB)\&.
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.sp
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|
\fBS0U\fR: Survivor space 0 utilization (kB)\&.
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.sp
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|
\fBS1U\fR: Survivor space 1 utilization (kB)\&.
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.sp
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\fBTT\fR: Tenuring threshold\&.
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.sp
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\fBMTT\fR: Maximum tenuring threshold\&.
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.sp
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\fBDSS\fR: Desired survivor size (kB)\&.
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.sp
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\fBEC\fR: Current eden space capacity (kB)\&.
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.sp
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\fBEU\fR: Eden space utilization (kB)\&.
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.sp
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\fBYGC\fR: Number of young generation GC events\&.
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.sp
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\fBYGCT\fR: Young generation garbage collection time\&.
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.RE
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.PP
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\-gcnewcapacity \fIoption\fR
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.RS 4
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New generation space size statistics\&.
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.sp
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\fBNGCMN\fR: Minimum new generation capacity (kB)\&.
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.sp
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\fBNGCMX\fR: Maximum new generation capacity (kB)\&.
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.sp
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\fBNGC\fR: Current new generation capacity (kB)\&.
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.sp
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|
\fBS0CMX\fR: Maximum survivor space 0 capacity (kB)\&.
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.sp
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\fBS0C\fR: Current survivor space 0 capacity (kB)\&.
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.sp
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\fBS1CMX\fR: Maximum survivor space 1 capacity (kB)\&.
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.sp
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\fBS1C\fR: Current survivor space 1 capacity (kB)\&.
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.sp
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\fBECMX\fR: Maximum eden space capacity (kB)\&.
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.sp
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\fBEC\fR: Current eden space capacity (kB)\&.
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.sp
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\fBYGC\fR: Number of young generation GC events\&.
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.sp
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\fBFGC\fR: Number of full GC events\&.
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.RE
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.PP
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\-gcold \fIoption\fR
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.RS 4
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Old generation and metaspace behavior statistics\&.
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.sp
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\fBMC\fR: Metaspace capacity (kB)\&.
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.sp
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\fBMU\fR: Metaspace utilization (kB)\&.
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.sp
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\fBCCSC\fR: Compressed class space capacity (kB)\&.
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.sp
|
|
\fBCCSU\fR: Compressed class space used (kB)\&.
|
|
.sp
|
|
\fBOC\fR: Current old space capacity (kB)\&.
|
|
.sp
|
|
\fBOU\fR: Old space utilization (kB)\&.
|
|
.sp
|
|
\fBYGC\fR: Number of young generation GC events\&.
|
|
.sp
|
|
\fBFGC\fR: Number of full GC events\&.
|
|
.sp
|
|
\fBFGCT\fR: Full garbage collection time\&.
|
|
.sp
|
|
\fBGCT\fR: Total garbage collection time\&.
|
|
.RE
|
|
.PP
|
|
\-gcoldcapacity \fIoption\fR
|
|
.RS 4
|
|
Old generation size statistics\&.
|
|
.sp
|
|
\fBOGCMN\fR: Minimum old generation capacity (kB)\&.
|
|
.sp
|
|
\fBOGCMX\fR: Maximum old generation capacity (kB)\&.
|
|
.sp
|
|
\fBOGC\fR: Current old generation capacity (kB)\&.
|
|
.sp
|
|
\fBOC\fR: Current old space capacity (kB)\&.
|
|
.sp
|
|
\fBYGC\fR: Number of young generation GC events\&.
|
|
.sp
|
|
\fBFGC\fR: Number of full GC events\&.
|
|
.sp
|
|
\fBFGCT\fR: Full garbage collection time\&.
|
|
.sp
|
|
\fBGCT\fR: Total garbage collection time\&.
|
|
.RE
|
|
.PP
|
|
\-gcmetacapacity \fIoption\fR
|
|
.RS 4
|
|
Metaspace size statistics\&.
|
|
.sp
|
|
\fBMCMN\fR: Minimum metaspace capacity (kB)\&.
|
|
.sp
|
|
\fBMCMX\fR: Maximum metaspace capacity (kB)\&.
|
|
.sp
|
|
\fBMC\fR: Metaspace capacity (kB)\&.
|
|
.sp
|
|
\fBCCSMN\fR: Compressed class space minimum capacity (kB)\&.
|
|
.sp
|
|
\fBCCSMX\fR: Compressed class space maximum capacity (kB)\&.
|
|
.sp
|
|
\fBYGC\fR: Number of young generation GC events\&.
|
|
.sp
|
|
\fBFGC\fR: Number of full GC events\&.
|
|
.sp
|
|
\fBFGCT\fR: Full garbage collection time\&.
|
|
.sp
|
|
\fBGCT\fR: Total garbage collection time\&.
|
|
.RE
|
|
.PP
|
|
\-gcutil \fIoption\fR
|
|
.RS 4
|
|
Summary of garbage collection statistics\&.
|
|
.sp
|
|
\fBS0\fR: Survivor space 0 utilization as a percentage of the space\*(Aqs current capacity\&.
|
|
.sp
|
|
\fBS1\fR: Survivor space 1 utilization as a percentage of the space\*(Aqs current capacity\&.
|
|
.sp
|
|
\fBE\fR: Eden space utilization as a percentage of the space\*(Aqs current capacity\&.
|
|
.sp
|
|
\fBO\fR: Old space utilization as a percentage of the space\*(Aqs current capacity\&.
|
|
.sp
|
|
\fBM\fR: Metaspace utilization as a percentage of the space\*(Aqs current capacity\&.
|
|
.sp
|
|
\fBCCS\fR: Compressed class space utilization as a percentage\&.
|
|
.sp
|
|
\fBYGC\fR: Number of young generation GC events\&.
|
|
.sp
|
|
\fBYGCT\fR: Young generation garbage collection time\&.
|
|
.sp
|
|
\fBFGC\fR: Number of full GC events\&.
|
|
.sp
|
|
\fBFGCT\fR: Full garbage collection time\&.
|
|
.sp
|
|
\fBGCT\fR: Total garbage collection time\&.
|
|
.RE
|
|
.PP
|
|
\-printcompilation \fIoption\fR
|
|
.RS 4
|
|
Java HotSpot VM compiler method statistics\&.
|
|
.sp
|
|
\fBCompiled\fR: Number of compilation tasks performed by the most recently compiled method\&.
|
|
.sp
|
|
\fBSize\fR: Number of bytes of byte code of the most recently compiled method\&.
|
|
.sp
|
|
\fBType\fR: Compilation type of the most recently compiled method\&.
|
|
.sp
|
|
\fBMethod\fR: Class name and method name identifying the most recently compiled method\&. Class name uses slash (/) instead of dot (\&.) as a name space separator\&. Method name is the method within the specified class\&. The format for these two fields is consistent with the HotSpot
|
|
\fB\-XX:+PrintCompilation\fR
|
|
option\&.
|
|
.RE
|
|
.SH "EXAMPLES"
|
|
.PP
|
|
This section presents some examples of monitoring a local JVM with an
|
|
\fIlvmid\fR
|
|
of 21891\&.
|
|
.SS "The gcutil Option"
|
|
.PP
|
|
This example attaches to lvmid 21891 and takes 7 samples at 250 millisecond intervals and displays the output as specified by the \-\fBgcutil\fR
|
|
option\&.
|
|
.PP
|
|
The output of this example shows that a young generation collection occurred between the third and fourth sample\&. The collection took 0\&.078 seconds and promoted objects from the eden space (E) to the old space (O), resulting in an increase of old space utilization from 66\&.80% to 68\&.19%\&. Before the collection, the survivor space was 97\&.02% utilized, but after this collection it is 91\&.03% utilized\&.
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
|
|
\fBjstat \-gcutil 21891 250 7\fR
|
|
\fB S0 S1 E O M CCS YGC YGCT FGC FGCT GCT \fR
|
|
\fB 0\&.00 97\&.02 70\&.31 66\&.80 95\&.52 89\&.14 7 0\&.300 0 0\&.000 0\&.300\fR
|
|
\fB 0\&.00 97\&.02 86\&.23 66\&.80 95\&.52 89\&.14 7 0\&.300 0 0\&.000 0\&.300\fR
|
|
\fB 0\&.00 97\&.02 96\&.53 66\&.80 95\&.52 89\&.14 7 0\&.300 0 0\&.000 0\&.300\fR
|
|
\fB 91\&.03 0\&.00 1\&.98 68\&.19 95\&.89 91\&.24 8 0\&.378 0 0\&.000 0\&.378\fR
|
|
\fB 91\&.03 0\&.00 15\&.82 68\&.19 95\&.89 91\&.24 8 0\&.378 0 0\&.000 0\&.378\fR
|
|
\fB 91\&.03 0\&.00 17\&.80 68\&.19 95\&.89 91\&.24 8 0\&.378 0 0\&.000 0\&.378\fR
|
|
\fB 91\&.03 0\&.00 17\&.80 68\&.19 95\&.89 91\&.24 8 0\&.378 0 0\&.000 0\&.378\fR
|
|
.fi
|
|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.SS "Repeat the Column Header String"
|
|
.PP
|
|
This example attaches to lvmid 21891 and takes samples at 250 millisecond intervals and displays the output as specified by
|
|
\fB\-gcnew\fR
|
|
option\&. In addition, it uses the
|
|
\fB\-h3\fR
|
|
option to output the column header after every 3 lines of data\&.
|
|
.PP
|
|
In addition to showing the repeating header string, this example shows that between the second and third samples, a young GC occurred\&. Its duration was 0\&.001 seconds\&. The collection found enough active data that the survivor space 0 utilization (S0U) would have exceeded the desired survivor Size (DSS)\&. As a result, objects were promoted to the old generation (not visible in this output), and the tenuring threshold (TT) was lowered from 31 to 2\&.
|
|
.PP
|
|
Another collection occurs between the fifth and sixth samples\&. This collection found very few survivors and returned the tenuring threshold to 31\&.
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
|
|
\fBjstat \-gcnew \-h3 21891 250\fR
|
|
\fB S0C S1C S0U S1U TT MTT DSS EC EU YGC YGCT\fR
|
|
\fB 64\&.0 64\&.0 0\&.0 31\&.7 31 31 32\&.0 512\&.0 178\&.6 249 0\&.203\fR
|
|
\fB 64\&.0 64\&.0 0\&.0 31\&.7 31 31 32\&.0 512\&.0 355\&.5 249 0\&.203\fR
|
|
\fB 64\&.0 64\&.0 35\&.4 0\&.0 2 31 32\&.0 512\&.0 21\&.9 250 0\&.204\fR
|
|
\fB S0C S1C S0U S1U TT MTT DSS EC EU YGC YGCT\fR
|
|
\fB 64\&.0 64\&.0 35\&.4 0\&.0 2 31 32\&.0 512\&.0 245\&.9 250 0\&.204\fR
|
|
\fB 64\&.0 64\&.0 35\&.4 0\&.0 2 31 32\&.0 512\&.0 421\&.1 250 0\&.204\fR
|
|
\fB 64\&.0 64\&.0 0\&.0 19\&.0 31 31 32\&.0 512\&.0 84\&.4 251 0\&.204\fR
|
|
\fB S0C S1C S0U S1U TT MTT DSS EC EU YGC YGCT\fR
|
|
\fB 64\&.0 64\&.0 0\&.0 19\&.0 31 31 32\&.0 512\&.0 306\&.7 251 0\&.204\fR
|
|
|
|
.fi
|
|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.SS "Include a Time Stamp for Each Sample"
|
|
.PP
|
|
This example attaches to lvmid 21891 and takes 3 samples at 250 millisecond intervals\&. The
|
|
\fB\-t\fR
|
|
option is used to generate a time stamp for each sample in the first column\&.
|
|
.PP
|
|
The Timestamp column reports the elapsed time in seconds since the start of the target JVM\&. In addition, the
|
|
\fB\-gcoldcapacity\fR
|
|
output shows the old generation capacity (OGC) and the old space capacity (OC) increasing as the heap expands to meet allocation or promotion demands\&. The old generation capacity (OGC) has grown from 11,696 kB to 13,820 kB after the eighty\-first full garbage collection (FGC)\&. The maximum capacity of the generation (and space) is 60,544 kB (OGCMX), so it still has room to expand\&.
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
|
|
\fBTimestamp OGCMN OGCMX OGC OC YGC FGC FGCT GCT\fR
|
|
\fB 150\&.1 1408\&.0 60544\&.0 11696\&.0 11696\&.0 194 80 2\&.874 3\&.799\fR
|
|
\fB 150\&.4 1408\&.0 60544\&.0 13820\&.0 13820\&.0 194 81 2\&.938 3\&.863\fR
|
|
\fB 150\&.7 1408\&.0 60544\&.0 13820\&.0 13820\&.0 194 81 2\&.938 3\&.863\fR
|
|
|
|
.fi
|
|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.SS "Monitor Instrumentation for a Remote JVM"
|
|
.PP
|
|
This example attaches to lvmid 40496 on the system named remote\&.domain using the
|
|
\fB\-gcutil\fR
|
|
option, with samples taken every second indefinitely\&.
|
|
.PP
|
|
The lvmid is combined with the name of the remote host to construct a
|
|
\fIvmid\fR
|
|
of
|
|
\fB40496@remote\&.domain\fR\&. This vmid results in the use of the
|
|
\fBrmi\fR
|
|
protocol to communicate to the default
|
|
\fBjstatd\fR
|
|
server on the remote host\&. The
|
|
\fBjstatd\fR
|
|
server is located using the
|
|
\fBrmiregistry\fR
|
|
command on
|
|
\fBremote\&.domain\fR
|
|
that is bound to the default port of the
|
|
\fBrmiregistry\fR
|
|
command (port 1099)\&.
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
|
|
\fBjstat \-gcutil 40496@remote\&.domain 1000\fR
|
|
\fB\fI\&.\&.\&. output omitted\fR\fR
|
|
|
|
.fi
|
|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.SH "SEE ALSO"
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
java(1)
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
jps(1)
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
jstatd(1)
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
rmiregistry(1)
|
|
.RE
|
|
.br
|
|
'pl 8.5i
|
|
'bp
|