Tuning HP-UX systems

This page describes how to tune the HP-UX operating system to optimize the performance of the WAS. Because the HP-UX operating system is not a WAS product, be aware that it can change and results vary

On the HP-UX operating system, WAS runs on the JVM, which is based on the technology of Sun HotSpot JVM. Properly tuning this JVM significantly affects WAS performance by fully utilizing its performance optimizing characteristics.

See the Tuning the IBM virtual machine for Java 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 WAS from being deprived of resources.

When we have a performance concern, check the operating system settings to determine if they are appropriate for the application.

 

• Set the following settings and variables according to the tuning needs:

  • Tuning the HP operating system with the DB2 type 2 JDBC driver When using the type 2 JDBC driver on the HP operating system with DB2, we can increase the performance of WAS by preallocating the DB2 trace segment. Perform the following steps:

    1. Before starting appserver, switch to the user that is associated with the DB2 instance.

    2. Run the db2trc alloc command.

    3. Start appserver.

    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 WAS performance. For additional information about the HP performance tuning parameters, see Performance: Links.

  • JVM virtual page size

    • Description: Sets the JVM instruction and data page sizes to 64 MB to improve performance.

    • To 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: 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

    • To 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

    • Description: Determines the interval between probes.

    • To set: Use the ndd command to determine the current value or to set the value. For example:

      ndd -set /dev/tcp tcp_keepalive_interval 7200000
      

    • Default value: None

    • Recommended value: 7200000 milliseconds

  • TCP_KEEPALIVES_KILL

    • Description: Determines the maximum number of times to probe before dropping.

    • To set: Use the ndd command to determine the current value or to set the value. For example:

      ndd -set /dev/tcp tcp_keepalives_kill 5000
      

    • Default value: 1

    • Recommended value: 5000 milliseconds

• Keeping current with the operating system and Java patches is one of the most important things we 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 WAS on the HP-UX operating system.

 

Next steps

After tuning the operating system for performance, consult the other tuning topics for various tuning tips.

 

Related tasks

Tuning Windows systems
Tuning Linux systems
Tuning AIX systems
Tuning Solaris systems