HP-UX Programmer's Guide for Java 2

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modify your HTML pages to specify use of the Runtime Plug-in for HP-UX, Java Edition,
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GC log-rotation support
Prior to SDK 1.4.2.23, when using GC logging options (for example, -Xverbosegc or
-Xloggc), GC data is written to a single file of unlimited size. Starting with SDK
1.4.2.23, the JVM supports generation of multiple GC log files and rotates through the
specified number of files. This allows for easier archiving of GC data and helps limit
the amount of disk space consumed by the GC log. Log rotation is also supported when
using zero-preparation Xverbosegc.
To enable log rotation, use the following option together with -Xverbosegc, -Xloggc,
or zero-preparation Xverbosegc:
-XX:GCLogLimits=M,N
M is a non-negative integer for the number of GC records per file. Each GC record
corresponds to a GC event. A value of 0 specifies an unlimited number of records per
file. N is a non-negative integer for the maximum number of files. A value of 0 specifies
an unlimited number of files.
When using this option, both M and N are required. If this option is not specified, then
the default behavior is to write a single GC log file with unlimited size.
When rotation is in effect, a sequence number is appended to the the GC filename (0
through N-1). (Examples of file names are: filename.0, filename.1, and filename.2.)
With log rotation, when the specified maximum number of files (N) is reached, logging
cycles back to the first file in the sequence (filename.0), overwriting old GC data with
new data. If the maximum number of files (N) is never reached, then no log rotation
occurs.
Examples:
Rotate between two log files, each with a maximum of 100,000 GC records:
-XX:GCLogLimits=100000,2
Maintain an unlimited number of smaller files, each with a maximum of 1,000 GC
records:
-XX:GCLogLimits=1000,0
ThreadDumpPath support
By default, sending the Java process a SIGQUIT signal results in a thread dump being
written to stdout. Starting with the SDK 1.4.2.25 release, the -XX:ThreadDumpPath=
<path/filename>option can be used to specify the thread dump file name or a
directory where the thread dump is created.
GC log-rotation support 93