[TechNote] How can LDAP connection pooling be configured in WebSphere Application Server with Standalone LDAP repository

How can LDAP connection pooling be configured in WebSphere Application Server with Standalone LDAP repository

Question

WebSphere Application Server Standalone LDAP repository does not provide management for LDAP connection pooling. While the application provider must manage LDAP connections in the application code itself, there are several JVM level properties that can be set to assist in this connection management.

Cause

In some instances, an application making and using its own connections to the LDAP server (for example, IBM Directory Server) might experience slowdowns in performance under heavy load. This is because the connections to LDAP server are not timed out after they are closed.

Answer

To resolve this situation, it is necessary to set parameters at the JVM command line level which define the LDAP connection pooling properties:
For example:
-Dcom.sun.jndi.ldap.connect.pool.maxsize=20
-Dcom.sun.jndi.ldap.connect.pool.prefsize=10
-Dcom.sun.jndi.ldap.connect.pool.timeout=300000
From the WebSphere Application Server Administrative Console:

1. Click on Servers -> Application Servers -> <server_name> -> Process Definition -> Java Virtual Machine ->
   In the 'Generic JVM arguments' field, enter each of the above properties separated with a space.
2. Click OK, save and synchronize the configuration, and then restart the server.

These parameters are documented in the following Java documentation:
http://java.sun.com/products/jndi/tutorial/ldap/connect/config.html