Introduction
Engine Sessions
An iIS process engine generally coordinates the work of a number of applications that perform various activities that comprise a business process. To manage this process flow, the engine needs to maintain sessions with each of the applications involved. Consequently, the first order of business of a client application or application proxy is to establish a session with any engines managing activities to be performed by the corresponding application.
NOTE In the remainder of this
When a client application attempts to open a session with an engine, the engine must verify the authenticity of the application or user. This validation is performed by the engine using logon information provided by the application or user and validation code in the validation registered with the engine. This validation code normally compares information provided by the user with information stored in an organization database.
The session is the mechanism for all communication between a client application and the engine. It is used by the engine to offer activities in a process to different applications or users and to notify them about changes in the status of these activities. It is used by the client application to accept activities to perform and notify the engine when work on an activity is complete.
A session can have the following states:
Session state | Description |
|
|
ACTIVE | A session to which the engine can assign |
| activities and post events. |
SUSPENDED | A session previously active, but now dormant. |
| This state can result from a lost connection |
| between client application and engine, or from |
| explicit action by a system manager or client |
| application user. The engine cannot assign |
| new activities to a suspended session or post |
| events to it. |
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