Overview
One of the core components of the iProcess Engine is the messaging system. This is used to deliver instructions from:
| • | all the TIBCO iProcess Workspaces to the background process |
| • | the Background process to the foreground processes |
Because of the potentially high volume of transactions in a TIBCO iProcess Engine system, there can be a large number of instructions trying to be passed from TIBCO iProcess Workspaces to the background to be processed. To prevent messages being lost or held up for long periods of time, a message queuing system is used so that all messages sent from TIBCO iProcess Workspaces or the background can be sent to a message queue. Once it is in the queue, the message has an assured delivery mechanism where it will be dequeued as system resources permit.
The message queues also ensure that a message instruction is only processed once (unless a transaction rollback occurs - see Transaction Management of Messages) and is processed even if system resources fail because it is retried when the system is running again. For example, in the case for banking transactions, a message to update a bank account must only be performed once and must be performed at some point even if the system has failed.
The iProcess Suite currently supports two message queuing systems:
| • | iProcess database queues (for the UNIX DB2 and Windows SQL Server versions) |
| • | Oracle AQ (for the UNIX Oracle and Windows Oracle versions) |
Both control the delivery and storage of iProcess messages.