(Dist) Tune HP-UX systems

Tune the HP-UX operating system to optimize the performance of the WebSphere Application Server. 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 setting up the JVM on the HP-UX system information. It is also important to change some parameters 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 whether they are appropriate for the application.

Tasks

• Configure the following settings and variables according to your tuning needs:
  • Tune 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 application server, switch to the user associated with the DB2 instance.

    2. Run the db2trc alloc command.

    3. Start application server.

    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 WAS 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: 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 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 Prepare HP-UX systems for installation topic in the information center.

  • TCP_KEEPALIVE_INTERVAL
    • Description: Determines the interval between probes.
    • How to view or 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.
    • How to view or set: Use the ndd command to determine the current value or to set the value. For example:

      ndd -set /dev/tcp tcp_keepalives_kill 1
      

    • Default value: 1
    • Recommended value: 1

• Keep current with the operating system and Java patches to optimize the performance of a server.

This tuning procedure improves performance of WAS on the HP-UX operating system.

What to do next

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

Tune Windows systems

Tune Linux systems

Tune AIX systems

Tune Solaris systems

Tune the IBM virtual machine for Java

DB2 tuning parameters

Performance: Resources for learning