Sun Microsystems 3 manual Disrupted Sessions, Reconnectioninprogress

	Introduction
Session state	Description
RECONNECTION_IN_PROGRESS	During engine recovery, a previously active
	session that is waiting to be restored to active
	during the engine recovery.

An ACTIVE or SUSPENDED session can be terminated by an application or user, or by a system manager. A RECONNECTION_IN_PROGRESS session can be suspended or terminated by a system manager. A session that has been terminated is deleted from the engine and the engine’s current state database table.

Disrupted Sessions

A session is a two-way communication between client application and engine. Both the client application and the engine maintain an object representing the session. The state of the engine object determines the state of the session. The client application’s session object uses code in the client API to restore the connection when a temporary disruption occurs. (A temporary disruption can be due to network interruptions or engine failure.)

The client session object tests the connection to the engine at regular intervals (refer to the iIS online help for the WFSession.SetPingInterval). When the client session object detects a disruption in the connection between the client application and the engine, it automatically attempts to restore the connection. If the client session object is unsuccessful in restoring the connection within a specified auto reconnect timeout period, it notifies the client application that the connection has been permanently lost. The auto reconnect timeout period is configured in a client application using the WFSession methods SetRetry and SetPingInterval.

Network failure The engine does not know about a network interruption until it touches an engine session object, for example, to post an event or assign an activity. If the engine finds the session disrupted, the engine suspends or terminates the session, depending on the value of the session’s disconnect action property (set using the control parameter to WFEngine.OpenSession or WFSession.SetControl).

Engine failure When a primary engine unit fails, all active sessions are automatically set to RECONNECTION_IN_PROGRESS. During recovery, sessions remain in this state for a specified timeout period (set in the engine’s configuration), waiting for the client sessions to reconnect. During this period, a system administrator can suspend or terminate these sessions.

Chapter 6 Managing Process Execution 159