Optimizing the group member cache heap size

To tune the group member caching, use the group-member-cache-memory-optimized and group-member-cache-max-size settings in the appropriate 100Custom.xml file. Because setting these properties might reduce the performance, it is recommended to consider them only if you are struggling with the current heap size and cannot make the heap larger.

Procedure

To reduce the heap usage, you can set the group-member-cache-memory-optimized property to true, which causes the cache objects to be stored with a reduced memory allocation. However, the drawback is that additional object conversions are needed when objects are retrieved from the cache, which could reduce performance.
For example:
```
<server merge="mergeChildren">                 
    <group-member-cache-memory-optimized merge="replace">true</group-member-cache-memory-optimized>
</server>
```
To limit the number of groups that are held in the GroupMembers cache, you can set the group-member-cache-max-size property. When the limit is reached, the least recently used (LRU) group will be replaced when a cache miss occurs.
For example, to limit the cache to 200 groups:
```
<server merge="mergeChildren">
    <group-member-cache-max-size merge="replace">200</group-member-cache-max-size>
</server>
```
Important: The actual memory size of the cache will depend on the size of the groups that are cached.