Recommendations for Resource Recovery Services

WebSphere Application Server for z/OS requires the use of the Resource Recovery Services Attach Facility (RRSAF) of DB2, which in turn requires that Resource Recovery Services (RRS) be set up. If you do not have RRS set up, the Customization Dialog helps you do this. See Using the Customization Dialog.

When setting up RRS, consider the following:

  1. You may have already configured RRS for z/OS to exploit WLM-managed DB2 Stored Procedures address spaces. However, if DB2 is the only RRS-compliant resource manager participating in transactional commits, optimizations will cause the system to bypass RRS usage of the system logger. This means that, while your installation may have configured RRS, your log streams might have just minimal activity. WebSphere Application Server for z/OS is an RRS-compliant resource manager and will participate in transactional commits with DB2. Thus, WebSphere Application Server for z/OS will require RRS to start writing data to its system logger log streams. You might need to adjust the size of your log streams.
  2. The Object Transaction Service in WebSphere Application Server for z/OS cannot detect when it has been restarted in a different logging group, which affects transaction recovery. We recommend you use automatic restart management (ARM) to control restart locations.
  3. For structure sizes, we recommend the following for initial setup values. Through experience, you may need to adjust these:
    Recommended size of log streams
    Log stream Initial size Size
    RM.DATA 1 MB 1 MB
    MAIN.UR 5 MB 50 MB
    DELAYED.UR 5 MB 50 MB
    RESTART 1 MB 5 MB
    ARCHIVE 5 MB 50 MB


    Check the MAXBUFSIZE on your log streams. If the size is too small, you may encounter DB2 failures.

Details about resource recovery are in z/OS MVS Programming: Resource Recovery. Details about the RRS Attach Facility are in DB2 for OS/390 Application Programming and SQL Guide.




Searchable topic ID:   cinsrrsset
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
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