The Database Event Channel (DEC) does not normally require any attention from developers: its default configuration is suited to most applications. A different configuration may be required for application-specific tuning. The main objective of configuring DEC is to control the flow of events from the database to the BPM Events engine, so that it provides optimal performance. Please note that except for the basic database access configuration parameters (already set in the Business Process Server configuration file), the following is only a tuning issue. In its default configuration, the DEC works fine for most applications.
The Database Event Channel involves two event queues:
Database event queue. Producers: event-generating components, like BP Server. Consumers: BPM Events DEC adapter (and other subscriber components, like BPM Process Store).
BPM Events entry queue. Producer: the DEC adapter of BPM Events. Consumer: BPM Events rule engine.
The configuration parameters (in oebpsdb.properties) used in configuring DEC are:
oebps.db.<dbname>.url specifies the URL of the data source from which to receive the events.
oebps.db.<dbname>.user specifies the name of the user of the database.
oebps.db.<dbname>.password specifies the password for the user of the database.
The configuration parameters (in bpmevents.conf) used in configuring DEC are:
bpmevents.server.eventsource.eventbatchsize specifies the maximum number of events that are pulled from the database at each fetch (query) operation.
bpmevents.server.eventsource.sleeptime specifies the sleeptime when there are no events in the BPMEvents table.
bpmevents.server.eventsource.sleeptime.whenevents specifies the sleeptime when there are more events in the BPMEvents table.
Database event queue. Producers: event-generating components, like BP Server. Consumers: BPM Events DEC adapter (and other subscriber components, like BPM Process Store).