IBM BS029ML - WebSphere Portal Server Self Help Manual page 170

Access control data management service
For improved performance during Portal access control lookups, you should avoid using
LDAP directories configured with nested groups (a group or groups inside a group). If this is
the case and your LDAP directory is not configured with nested groups, then the attributes
shown in Table 5-16 can be modified to allow improved performance during user searches by
limiting the search to the first level of the group.
Table 5-16 Access control data management service
Parameter
accessControlDataManageme
nt.enableNestedGroups
If no nested groups exist in your LDAP or Custom User Registry, the parameter documented
in Table 5-16 can be modified. Consult the Information Center for additional parameters that
can be modified.
Cache Manager Service
Caching is fundamental to the performance of WebSphere Portal Server. For this reason
Portal implements several additional internal caching mechanisms above those found in the
underlying WebSphere Application Server instance. For maximum flexibility the
characteristics of the majority of these cache instances are configurable through the settings
found in the Cache Manager Service. In most environments the default out-of-the-box
settings will suffice, leaving modifications only necessary if a high number of cache misses
are observed for a concerned entry when viewed with Performance Viewer.
However, one important parameter found under the Cache Manager Service property settings
is the cacheglobal.size directive. At first glance this setting would appear to be a catchall for
any caches not specified further on in the file.
Table 5-17 Cache Manager Service
Parameter
cacheglobal.enabled
cacheglobal.size (number of
entries)
cacheglobal.shared
cacheglobal.replacement
cacheglobal.admit-threshold
cacheglobal.lifetime
Under certain conditions typically associated with aggressive load testing, the global cache
can experience thrashing associated with implementing a Least-Recently-Used (LRU)
eviction strategy. A worst case load test scenario, for example, might log in 1000 users, at
which point in time the global cache will become fully occupied. By increasing the
cacheglobal.size value from the 1000 default entries, this problem can be overcome. Careful
consideration should nevertheless be exercised, as additional cache entries will consume
more Java memory. It also follows that Portal cluster deployments support an accumulative
number of entries based on the number of server members participating in the cluster.
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IBM WebSphere Portal V6 Self Help Guide
Default value
true
Default
true
1000
false
moderate
0
Recommended value
false
Recommended
true.
Increase if necessary.
See notes and InfoCenter.
See notes and InfoCenter.
See notes and InfoCenter.
See notes and InfoCenter.