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Restarting the Process Server clears the caches so if code is deployed and it is required that
the change is recognized immediately, the Process Server can be restarted, or the PO cache
can be reset through the Process Admin console under the Manage Caches link.
A related configuration setting is the number of objects in the cache. Two configuration flags
in 00Static.xml file can manage this value:
► 500
► 500
For low volume environments with relatively few process applications and coaches, this value
may be sufficient. However, for more complex environments with many process applications
or coaches, increase this value so that the process applications and coaches are held in the
cache of their initial use. This step can improve response time when accessing these process
applications and coaches. For example, increase each of these values to 1500.
When the cache is “cold” after a restart, initial coach load times might take longer until the
cache is populated.
The effectiveness of these caches can be monitored through the Instrumentation Page in the
Process Admin console, which indicates how many cache hits and misses occurred. For
more detailed analysis, obtain Instrumentation logs from this page, and which can be
analyzed by IBM Support through a PMR to determine whether further cache-size increases
are warranted.
The UCP column in the Manage Caches page of the Process Admin console can also be
used to monitor how effectively the cache is working for a particular runtime server. The
Process Admin console has online help that describes the column headings and their
meanings.
User group membership information is also stored in a cache so a company with a large
LDAP user and group population may require a larger setting for LDAP caches to avoid a
performance impact when user/group information is accessed, such as during authorization
validation for task assignment, login to Process Portal, or refreshing the Task List in Process
Portal.
Cache settings for memory-constrained environments
In a memory-constrained environment, such as when using a 32-bit JVM, a beneficial
approach might be to reduce the size of some caches. An example is the number of
snapshots that are cached for a single branch in the Process Center. For very large process
applications, reducing this value can reduce JVM heap memory usage. Reduce the following
value to accomplish this goal:
64
Similarly, for a Process Server in a memory-constrained environment, reducing the Branch
Manager cache size can reduce heap memory for large process apps. The Branch Manager
cache contains metadata about the contents of snapshots in memory, and is used to improve
performance of certain operations. It is controlled by the configuration flag:
64
The default value is 64. If process applications are particularly large, reducing this value might
be necessary, particularly for runtime servers where a new branch is created for each
deployed snapshot.
Chapter 4. Performance tuning and configuration 61