Oracle^® Business Intelligence Server Administration Guide > Clustering Oracle BI Servers >

Performance Considerations

This section describes characteristics of the Cluster Server that may influence the performance of clustered Oracle BI Servers. You should consider these points when implementing the Cluster Server.

• Sessions are assigned to an Oracle BI Server when the session is established. A session is assigned to the server with the fewest sessions. As a result, the load on Oracle BI Servers can vary and Oracle BI Servers brought online into an operational cluster may not receive work for some time.
• Because each Oracle BI Server maintains its own local query results cache, back-end databases may receive the same query from multiple Oracle BI Servers even though the result is cached. If you are using cluster aware caching, queries that are explicitly seeded through a cache seeding iBot are shared across nodes in the cluster. For more information, see Oracle Business Intelligence Enterprise Edition Deployment Guide.
• Because each Oracle BI Server maintains its own local query results cache, Oracle BI Servers that are brought online into an operational cluster may respond to queries more slowly while their local cache is being populated.
• Because each Oracle BI Server has an independent copy of each repository and hence its own back-end connection pools, back-end databases may experience as many as N*M connections, where N is the number of active servers in the cluster and M is the maximum sessions allowed in the connection pool of a single repository. Therefore, it may be appropriate to reduce the maximum number of sessions configured in session pools.