ExecutionPlan Configuration

Connection mode

During the execution of a plan the execution may be moved to a number of execution hosts (boundaries). This can create an arbitrarily big connection tree as the plan desires it. All these execution boundaries are connected in pairs. The type of connection can be configure to one of the two:

• KeepAlive

  In this case the connection is made and is kept open until the completion of the execution of the connected boundary. Since this connection is only used to pass execution data in the beginning of the connection and then the results of the execution when the boundary is about to complete, in the meantime the connection remains idle. Control data are not send through this channel but through a different one.

• Callback

  In this case the connection is made, the party that initialized the connection sends the execution details nad the connection is then closed. The accepting party then when it is ready to send back the execution results connects back to a specific callback address the caller supplied to report the results. A timeout can also be set when using this connection mode after which the connection is considered inactive and the initiating party stops waiting for results from the listener.

Event Choking

By default while an plan is executed, a number of progress reporting events are emitted by the Plan Elements. For any reasons the client may not want to be informed of such events. There is the option of disabling these events through the plan configuration class. The two types of events that can be choked by the execution engine are:

• Progress reporting events
• Performance reporting events