Each AppServer consists of an AppServer broker and one or more AppServer agents. An AppServer agent is a single ABL Virtual Machine (AVM) instance running on an AppServer. Each AppServer agent executes ABL procedures on behalf of AppServer clients, including ABL and Open Clients (Java, .NET, and Web services clients).
An AppServer can support clients using two different session models, which are dependent on its operating mode:
Session-managed — Includes stateless, state-aware, and state-reset operating modes. These operating modes maintain a single session and connection between the AppServer and the client for all client requests.
Session-free — Includes only the state-free operating mode. This operating mode maintains no session or connection between the AppServer and the client. In this operating mode, the AppServer treats any request from a client as independent from all other requests. As a result, some SESSION handle attributes in the ABL application have no valid meaning, or they provide different information.
The AppServer supports these session models for supported AppServer clients.
For more information, see OpenEdge Application Server: Developing AppServer Applications.
Session-managed — Includes stateless, state-aware, and state-reset operating modes. These operating modes maintain a single session and connection between the AppServer and the client for all client requests.