KB8780: How does the connection caching feature interact with the connection mapping feature in MicroStrategy Intelligence Server

Strategy Intelligence Server uses connection caching in order to reuse warehouse database connections. This minimizes the overhead associated with repeatedly connecting to and disconnecting from the warehouse database.
 
Refer to the following Strategy Knowledge Base document for details on the connection caching settings in Strategy Intelligence Server:
 

• KB5598  - What are the 'Connection lifetime' and 'Connection Idle Timeout' options under the Database Connection Caching section in Strategy Intelligence Server?

Connection mapping is the process of mapping Strategy users to database connections and database logins. It is set in the Project Configuration editor in Strategy Desktop. If no connection mapping is set for a Strategy user, the default connection map is used for that user. Refer to the following Strategy Knowledge Base technical note for details on setting up connection mapping in Strategy Intelligence Server:
 

• KB20740  - What is Connection Mapping and how is it configured in Strategy Developer?

The 'Database Connection Monitor' interface in Strategy Developer displays the parameters of the open connections to the database. These parameters include Connection ID, Status (busy or cached), Database Instance, Database Connection, User Name and Database Login. The following is a screen-shot of how the 'Database Connection Monitor' interface appears in Strategy Developer:
 

 
The following points depict the interaction between connection caching and connection mapping:
 

1. A user assigned with a connection map may not use a connection cached for another user unless both users have the exact same connection mapping. Instead, a new connection will be created. A distinct connection map is characterized by its Database Instance - Database Login combination.
    
   
2. The Database Connection Monitor displays the number of Database Connections (cached or busy) connected to the warehouse database at any time. The displayed connections may be greater than the number of connections specified in Database Instance Manager > Database Instance > Job Prioritization. The latter setting only controls the number of busy connections to the database, i.e. the concurrent connections in use.
    
   
3. The maximum number of possible Database Connections that can be concurrently connected to the warehouse is equivalent to the number of distinct connection maps multiplied by the number of connections specified in Database Instance Manager > Database Instance > Job Prioritization.
    
   
4. Each Database Connections within the Database Connection Monitor (cached or busy) in multi-process mode corresponds to one M8MULPRC/MJMulPrc_64 process running on the Strategy Intelligence Server machine (or on the Strategy Developer machine, if using 2-tier mode).