Configuring the Partition Cache
The COM+ partitions feature includes a partition cache. This cache stores user-to-partition mappings and is designed to avoid repetitive Active Directory access.
Changing Cache Size
The partition cache consists of three tables, whose size can be modified to enhance performance. These tables consist of the number of SID entries in the cache, the number of OU entries in the cache, and the number of partition entries in the cache.
To change these table sizes, administrators can modify the values of a registry key. The registry key and its values are as follows:
HKLM\SOFTWARE\Microsoft\COM3\PartitionCache
| Key values | Description |
|---|---|
| NumSidEntries |
Contains the REG_DWORD value for the number of SID entries in the cache (default=512). This value should be set to a value greater than the number of unique identities that a machine will be servicing in the cache invalidation time window. |
| NumNameEntries |
Contains the REG_DWORD value for the number of OU name entries in the cache (default=64). This value should be set to a value greater than the number of unique OU names that a machine will be servicing in the cache invalidation time window. |
| NumPartitionEntries |
Contains the REG_DWORD value for the number of partition entries in the cache (default=1024). In the cache invalidation time window, the DWORD value should be set to a number greater than the number of unique partitions that a machine will be servicing. This is because a component's context can include a partition ID for a partition that does not reside on that machine. |
| EntryExpiration |
Contains the REG_DWORD value for the tick count (each tick = ~7 minutes) until a cache entry becomes invalid (default=4 (~28 minutes)). |
Flushing the Cache
Because COM+ caches the default partition for users, you might want to call this method after changing the default partition for a user in the Active Directory. Administrators can do this programmatically by calling the FlushPartitionCache method.