NonStop Server for Java 6.0 Tools Reference Pages

(-Xss512k). You can use this option to increase the stack size if you experience stack overflow
exceptions. The default units for n are bytes; n must be greater than 1000 bytes. To modify the
meaning of n, append either the letter k (or K) to indicate kilobytes, or the letter m (or M) to indicate
megabytes. For example, –Xss10240 and –Xss10k are equal.
-Xincgc
Specifies using the incremental low-pause garbage collector. This option is supported but using it can
lead to about a 10% decrease in garbage collection performance.
Deviations from Nonstandard Java Options
-Xmsn
Specifies the initial size, in bytes, of the memory-allocation pool. The default value is implementation
specific; the value is about 3.6 megabytes.
HP Extensions to Standard Java Options
-nsjversion
Prints the NonStop Server for Java 6.0 build version.
HP Extensions to NonStandard Java Options
-Xabend
Turns on the abend option to abort the process instead of exiting with a non-zero exit code. If the NonStop Server
for Java 6.0 application runs as a Pathway server, you can enable this option to alert Pathmon to restart the server
after the NonStop Server for Java 6.0 application dies.
-XX:GuaranteeFreeHeapSizeAfterGC=<number>
Prevents excessive garbage collection (GC) activity in Java applications that have not been tuned well with respect
to GC. If the application uses almost all of the memory heap and the Java virtual machine is unable to collect much
garbage, excessive GC activity might occur to satisfy the demand for allocation of new objects. This activity may
result in a busy CPU in which the Java application is executing. To prevent this occurrence, use the
-XX:GuaranteeFreeHeapSizeAfterGC=<number> option, where <number> is specified in bytes,
kilobytes (k), or megabytes (m). After a GC, if the Java virtual machine cannot free the heap size more than the
value specified with the GuaranteeFreeHeapSizeAfterGC option, the Java virtual machine throws an
OutOfMemoryError.
-XX:+ForceStopableMode
Forces the Java process stop mode to 1 (stoppable) when a Java thread transitions to native state.
Under certain rare conditions, the Java Virtual Machine (JVM) can incorrectly be running in unstoppable mode,
which can result in a processor halt if the JVM process hits a trap or exception.
Normally, the process stop mode is set to unstoppable by privileged code when the code is run, and set back to
stoppable mode on exit to the calling routine. While Java itself does not run in privileged mode when executing
Java bytecodes, Java application code as well as the JVM can make calls to native code or system APIs that run
privileged code. If any of these privileged routines do not reset the stop mode on exit, it can result in a processor
halt if a trap occurs. Enable this flag to avoid a processor halt in case the stop mode has been set incorrectly by
privileged code. Some applications may see performance degradation when this flag is enabled.