Several features describe the relationship between a client application and the PAS for OpenEdge environment. For example:
A client application can have connections to multiple PAS for OpenEdge instances simultaneously.
A session-free client application can connect specifically to one OE ABL Web application running a given business application on a single PAS for OpenEdge instance or to multiple PAS for OpenEdge instances running the same business application using a DNS load balancing service.
How the the session manager of a PAS for OpenEdge instance allocates server sessions to service client requests that it receives depends on the application model that the client uses to connect to the PAS for OpenEdge instance.
Note: Just as you must write the business application according to the application model (or models) that it supports, you must accordingly to write the client application to access and manage responses from PAS for OpenEdge.
A PAS for OpenEdge business application can manage transactions in a number of ways. The transaction management mechanism used by PAS for OpenEdge sessions is completely transparent to the client. The client has no direct control over the transaction mechanics used by the PAS for OpenEdge business application, but the business application implements a transaction model that works with the application model that it expects to run in.
A client application can have connections to multiple PAS for OpenEdge instances simultaneously.