The Resource Manager is a component that manages the resources available to and exposed by an OGSA-DAI server and the accessing of these from the OGSA-DAI persistence and configuration components (in particular a resource state DAO). Resource managers are an extensibility point in OGSA-DAI - developers may develop their own.

Deploying a resource manager in OGSA-DAI is described in Section 18.5, “Resource manager”.

The Activity Manager (also termed the Activity Specification Manager) is a component that manages the activities available to an OGSA-DAI server and the accessing of these from the OGSA-DAI persistence and configuration components (in particular an activity specification DAO). Activity managers are an extensibility point in OGSA-DAI - developers may develop their own.

Deploying an activity manager in OGSA-DAI is described in Section 18.6, “Activity manager”.

The Common Components Configuration Manager is a component that manages the configuration of common OGSA-DAI components and the accessing of this configuration from the OGSA-DAI persistence and configuration components (in particular a common components configuration DAO). Common components configuration managers are an extensibility point in OGSA-DAI - developers may develop their own.

Deploying a common components configuration manager in OGSA-DAI is described in Section 18.7, “Common components configuration manager”.

The Persistence Manager is a component that manages the persistence and configuration of OGSA-DAI components. It is a layer which interacts with persistence media so shielding information about persistence media from the rest of an OGSA-DAI server. It is an extensibility point which by default supports configuration from and persistence via text files but developers are free to implemnt their own.

A persistence manager provides three DAOs or data access objects which are responsible for configuring and persisting the three main classes of OGSA-DAI object:

When OGSA-DAI starts up it creates the persistence manager, resource, activity and common components configuration managers. It then ensures that each manager gets a reference to the associated DAO to handle all persistence and configuration.

Deploying a persistence manager in OGSA-DAI is described in Section 18.4, “Persistence manager”.