What is an Oracle Directory Server Instance?

Each Oracle directory server instance is also called an LDAP server instance.

1. The Oracle Internet Directory listener/dispatcher sends the request to the Oracle directory server which, in turn creates server processes. 
   
2. A server process handles an LDAP operation request and connects to the Oracle database instance to access the directory store
   
3. The directory server handles the client request by generating one server process for each operation.
   

The number of server processes created is determined by the configuration parameter ORCLSERVERPROCS. The default is 1 (one). 

Database connections from each server process are spawned as needed, depending on the value set for the configuration parameter ORCLMAXCC. The number of database connections spawned by each server is equal to ORCLMAXCC + (ORCLMAXCC/2) + 1. The default value of ORCLMAXCC in configset0 is 2. The server processes communicate with the data server by way of Oracle Net Services. an Oracle Net Services Listener/Dispatcher relays the request to the Oracle Database.