The following tuning parameters are specific to the Solaris operating
system. Because the Solaris operating system is not a WebSphere Application
Server product, be aware that it can change and results vary.
About this task
On the Solaris operating system, WebSphere Application Server runs
on the Sun Hotspot Java virtual machine (JVM). It is important to use the
correct tuning parameters with the Sun JVM to utilize its performance optimizing
features. Refer to the
Tuning Java virtual machines topic for more information about tuning the JVM.
Also, consider the following parameters that are specific to the Solaris
operating system to ensure that WebSphere Application Server has enough resources.
Procedure
Configure the following settings or variables according to your
tuning needs:
- Solaris file descriptors (ulimit)
- Description: Specifies the maximum number of open files supported.
If the value of this parameter is too low, a Too many files open error
is displayed in the WebSphere Application Server stderr.log file.
- How to view or set: Check the UNIX reference pages on the ulimit command
for the syntax of different shells. For the KornShell (ksh) shell use the ulimit
-n 1024 command. Use the ulimit -a command to display the current
settings. Use the ulimit -n 2000 command to set the values.
- Default value: None
- Recommended value: 8000
- Solaris TCP_TIME_WAIT_INTERVAL
- Solaris TCP_FIN_WAIT_2_FLUSH_INTERVAL
- Solaris TCP_KEEPALIVE_INTERVAL
- Solaris kernel semsys:seminfo_semopm
- Description: An entry in the /etc/system file
can exist for this tuning parameter. This number is the maximum value of System
V semaphore operations per semop call. The default value for this option is
too low for highly concurrent systems.
- How to view or set: Set this parameter through the /etc/system entry: semsys:seminfo_semopm
= 200
- Default value: None
- Recommended value: 200 (100 is appropriate for most systems, but
200 might be needed in some cases.)
- Connection backlog
- Large page support
Using large pages can
reduce the CPU overhead of managing a large JVM heap.
With Solaris
9, large page support is provided by default. No operating system or JVM parameters
are necessary to make use of large pages for the JVM heap.
With Solaris
8, the Intimate Shared Memory (ISM) feature must be utilized to provide large
page support. See the http://java.sun.com/docs/hotspot/ism.ht Web site for instructions to enable large page support.
Results
This tuning procedure improves the performance of WebSphere Application
Server on the Solaris operating system.
What to do next
After tuning your operating system for performance, consult other
tuning topics for various tuning tips.