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.