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ADF Application Module Pooling

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1. An application module pool is a collection of application module instances of the same type.

2. This pool of application module instances is shared by multiple browser clients whose typical "think time" between submitting web pages allows optimizing the number of application module components to be effectively smaller than the total number of active users working on the system.

3. That is, twenty users visiting the web site from their browser might be able to be serviced by 5 or 10 application module instances instead of having as many application module instances as you have browser users.

4. As a performance optimization, when an instance of an application module is returned to the pool in "managed state" mode, the pool tracks session references to the application module.
The application module instance is still in the pool and available for use, but it would prefer to be used by the same session that was using it the last time because maintaining this so-called "session affinity" improves performance.

5. So, at any one moment in time, the instances of application modules in the pool are logically partitioned into three groups, reflecting their state:
    -  Unconditionally available for use
    -  Available for use, but referenced for session affinity reuse by an active user session
    -  Unavailable, as it's currently in use.

6. Basically speaking, Oracle ADF application works with two pools
     - Application Module pool and Database Connection pool.
   Application pool allows to optimize application work on middle tier, while Database pool cares  about database  connections

Activation and Passivation in ADF

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