This topic describes how to tune the HP-UX operating system to
optimize the performance of your WebSphere Application Server. Because the
HP-UX operating system is not a WebSphere Application Server product, be
aware that it can change and results vary
Before you begin
On the HP-UX operating system, WebSphere Application Server runs
on the Java virtual machine (JVM), which is based on the technology of Sun
HotSpot JVM. Properly tuning this JVM significantly affects WebSphere Application
Server performance by fully utilizing its performance optimizing characteristics.
See the
Tuning Java virtual machines topic
for details on setting up the JVM on the HP-UX system. It is also important
to change some parameters that are specific to the HP-UX operating system
to prevent WebSphere Application Server from being deprived of resources.
About this task
When you have a performance concern, check the operating system settings
to determine if they are appropriate for your application.
Procedure
- Configure the following settings and variables according to your
tuning needs:
- Tuning the HP operating system with the DB2 type 2 JDBC driver
When
using the type 2 Java Database Connectivity (JDBC) driver on the HP operating
system with DB2, you can increase the performance of WebSphere Application
Server by preallocating the DB2 trace segment. Perform the following steps:
- Before starting application server, switch to the user that is associated
with the DB2 instance.
- Run the db2trc alloc command.
- Start application server.
Usage note: Use the type 4 driver for best performance
and compatibility.
Another issue with the type 2 JDBC driver on the
HP operating system is code page conversion. Creating the database using the
UTF-8 code set avoids this problem and significantly increases performance.
See the database documentation for instructions on creating databases with
a specific code set. Refer to DB2 tuning parameters for
information about DB2 tuning parameters.
- The HP performance tuning parameters
Modify HP-UX 11i settings
to significantly improve WebSphere Application Server performance. For additional
information about the HP performance tuning parameters, see Performance: Resources for learning.
- Java virtual machine (JVM) virtual page size
- Description: Sets the JVM instruction and data page sizes to 64
MB to improve performance.
- How to view or set: Use the WASHOME/java/bin/SYSTEM_ARCH_PATH/java command.
The command output provides the current operating system characteristics of
the process executable.
- Default value: 4 MB, if not assigned
- Recommended value: 64 MB
- HP-UX 11i TCP_CONN_REQUEST_MAX
- Description: Specifies the maximum number of connection requests
that the operating system can queue when the server does not have available
threads. When high connection rates occur, a large backlog of TCP/IP connection
requests builds up and client connections are dropped. Adjust this setting
when clients start to time out after waiting to connect. Verify this situation
by issuing the netstat -p tcp command. Look for the following value:
connect requests dropped due to full queue
- How to view or set: Set this parameter by using the ndd -set
/dev/tcp tcp_conn_request_max 8192 command.
- Default value: 4096
- Recommended value: In most cases the default is sufficient. Consider
adjusting this value to 8192, if the default proves inadequate.
- HP-UX 11i kernel parameter recommendations
Refer
to the table of kernel parameters shown in the "Preparing HP-UX systems for
installation" topic in the information center for your Version 6.1 WebSphere
Application Server product.
- TCP_KEEPALIVE_INTERVAL
- TCP_KEEPALIVES_KILL
- Keeping current with the operating system and Java
patches is one of the most important things you can do to optimize the performance
of a server. For the latest Java patches, visit the following Web site:
HP-UX
Patch Information
Also, for the latest operating system quality
pack, visit the following Web site:
Support Plus: Quality Pack Bundles
Results
This tuning procedure improves performance of WebSphere Application
Server on the HP-UX operating system.
What to do next
After tuning your operating system for performance, consult the other
tuning topics for various tuning tips.