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:
- 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.
- WebSphere Application Server for z/OS has no significant impact on the
RM.DATA log.
- Depending on the transaction policies of both the client and container,
you may not see any activity in the MAIN.UR log. This lack of activity is
not a problem.
- Depending on the transactional policy defined for your containers, you
may see much more activity in your DELAYED.UR log stream than in the MAIN.UR
log stream.
All RRS transaction logging for WebSphere Application Server
for z/OS will occur solely in the DELAYED.UR log stream. You may still want
to configure your MAIN.UR log stream so that it can handle a production workload,
in case you deploy a new container or the WebSphere Application Server for
z/OS infrastructure changes.
- WebSphere Application Server for z/OS has no significant impact on the
RESTART log.
- There is no reason to change your policy about the ARCHIVE log. Though
optional, we suggest you use the ARCHIVE log. It has a small negative effect
on performance. Set the retention period for the log as you would normally.
- 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.
- 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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