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 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 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. 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. 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.
- 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 website:
HP-UX
Patch Information
Also, for the latest operating system
quality
pack, visit the following website:
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.