This chapter contains general information about real-time processing. Real-time processing behavior depends on the real-time source. Exceptions are noted in this chapter or are described in the corresponding product documentation.
You can use PowerCenter to process data in real time. Real-time processing is on-demand processing of data from real-time sources. A real-time session reads, processes, and writes data to targets continuously. By default, a session reads and writes bulk data at scheduled intervals unless you configure the session for real-time processing.
To process data in real time, the data must originate from a real-time source. Real-time sources include JMS, WebSphere MQ, TIBCO, webMethods, MSMQ, SAP, and web services. You might want to use real-time processing for processes that require immediate access to dynamic data, such as financial data.
To understand real-time processing with PowerCenter, you need to be familiar with the following concepts:
Real-time data.
Real-time data includes messages and messages queues, web services messages, and changes from a PowerExchange change data capture source. Real-time data originates from a real-time source.
Real-time sessions.
A real-time session is a session that processes real-time source data. A session is real-time if the Integration Service generates a real-time flush based on the flush latency configuration and all transformations propagate the flush to the targets. Latency is the period of time from when source data changes on a source to when a session writes the data to a target.
Real-time properties.
Real-time properties determine when the Integration Service processes the data and commits the data to the target.
Terminating conditions.
Terminating conditions determine when the Integration Service stops reading data from the source and ends the session if you do not want the session to run continuously.
Flush latency.
Flush latency determines how often the Integration Service flushes real-time data from the source.
Commit type.
The commit type determines when the Integration Service commits real-time data to the target.
Message recovery.
If the real-time session fails, you can recover messages. When you enable message recovery for a real-time session, the Integration Service stores source messages or message IDs in a recovery file or table. If the session fails, you can run the session in recovery mode to recover messages the Integration Service could not process.
