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 setting up the JVM on the HP-UX
system information. 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
whether 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.
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. Read the DB2
tuning parameters information.
- 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 the performance: resources for learning information.
- 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. Adjust 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.
- TCP_KEEPALIVE_INTERVAL
- TCP_KEEPALIVES_KILL
- Keep current with the operating system and Java patches to optimize the
performance of a server.
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.