JCO Client Pool 

You can get a JCO client out of the client pool of clients by using the method getJCOClientPoolEntry(). The methods returns a JCOClientPoolEntry object that contains a JCO client. Every time the getJCOClientPoolEntry() method is called, a new JCOClientPoolEntry object is returned. However, the contained JCO client can be the same, depending on the pool contents. After getting the pool entry, the application extracts the JCO clientby calling the method getClient(). After calling all the necessary function modules, the JCO client has to be released to the pool again by calling the release() method. When the JCO client is released, it is available for the method getJCOClientPoolEntry() again.

The JCO client service provides one pool of JCO clients for a combination of user, JCO destination and HTTP session. The JCO client service creates different pools for the same user, if he accesses different JCO destinations or is logged in from different browser, with different HTTP sessions.