Tuning access to the LDAP server

Set the context pool parameters to improve the performance of concurrent access to an LDAP server.

About this task

The context pool is used in virtual member manager to improve the performance of concurrent access to an LDAP server. Use the Integrated Solutions Console on the deployment manager. You can also edit values in the wimconfig.xml file stored here:

C:\ProgramFiles\IBM\WebSphere\AppServer\profiles\ST_Advanced_Profile\config
			\cells\machineNameCell\wim\config\wimconfig.xml
Note: The following instructions contain settings that were tested in IBM® labs. Adjust these settings as needed for your specific environment.

Procedure

  1. In the Integrated Solutions Console for the deployment manager, click Security > Global security.
  2. Under User account repository, select Federated repositories from the Available realm definitions field and click Configure.
  3. Under Related items, click Manage repositories.
  4. Select the configured LDAP repository.
  5. Under Additional properties, click Performance.
  6. Set the following context pool parameters:
    Table 1. Performance parameters
    Parameter Description
    Maximum size (maxPoolSize): 200 Specifies the maximum number of live Connections. If there is no available connection in the pool when the request is submitted, the request waits the number of milliseconds specified in poolTimeOut. After this amount of time has passed, if no connection is available and the current number of live Connections is less than the maxPoolSize, a new connection is created. If the total number of live Connections is equal to or larger than maxPoolSize, an exception is thrown.
    (Can be set only in the wimconfig.xml file) poolWaitTime="5000" Specifies the number of seconds a connection can exist in the connection pool. When requesting a connection from the pool, if this connection already exists in the pool for more than the time defined by poolWaitTime, this connection is closed and a new connection is created for the request. After the connection is used it is returned to the pool.

    If this parameter is set to 0, a new connection is created for each request and no connection are put into the pool for reuse. If this parameter is set to -1 or any negative number, the connection does not expire and is reused until the connection is turned off (for example by a firewall or a socket timeout). The default value is -1.
    Preferred size (prefPoolSize): 20 Specifies the preferred number of context instances that the context pool will maintain. Context instances that are in use and those that are idle contribute to this number. When there is a request for the use of a pooled context instance and the pool size is less than the preferred size, the context pool creates and uses a new pooled context instance regardless of whether an idle connection is available. When a request finishes with a pooled context instance and the pool size is greater than the preferred size, the context pool closes and removes the pooled context instance from the pool.

    The valid range for this parameter is from 0 to 100. Setting the value of this parameter to 0 means that there is no preferred size and a request for a pooled context instance results in a newly created context instance only if no idle ones are available. The default value is 3.

    Cache the attributes Cache size: 80000 Specifies the number of LDAP attributes that are cached by the server.
    Cache the search results Cache size: 80000 Specifies the number of LDAP search results that are cached by the server.
  7. Save the changes.