Database Reference
In-Depth Information
Select heap size
Set the values of
-Xms
and
-Xmx
to around 80 percent of the available physical
memory on a server. The remaining 20 percent memory is left for the operating sys-
tem and other processes. Setting the value of
-Xmx
to a very high value will result in
a slower majorGC that occurs less frequently. Setting too high values for a JVM heap
size can cause wasted memory and performance impact during a majorGC. Please
note that on a 32-bit OS server(s) a JVM can only use a maximum 2.5 GB.
Garbage collection tool - JVisualVM
JVisualVM
is a GUI-based JVM monitoring, troubleshooting, and profiling tool that
can be used to diagnose JVM performance, JVM garbage collection processes to
tune JVM parameters for an application platform such as Oracle SOA Suite. The
JVisualVM tool is part of JDK Version 6 that combines several JVM utilities such as
JConsole, jstat, jinfo, jstack, and jmap under one roof.
To start the JVisualVM, go to the
bin
directory of the JDK install and invoke
the
jvisualvm
application. The Java Visual VM tool provides a view of all the
Java parameters set for a WebLogic server environment, as shown in the following
screenshot:
