NRDBMessageRetriever

Renamed from NRDBReaderV2. The purpose of this engine is to connect to NRDB, retrieve a batch of new unread messages from NRDB and create corresponding records in NRDB_MESSAGE_TYPE table.

NRDBMessageTypeHandler

Renamed from NRDBMessageReaderV2. The purpose of this engine is to pick unhandled messages from the NRDB_MESSAGE_TYPE table and handle them according to their code. For outgoing messages, an NRDBMessageSender is created and the message is send to NRDB. For incoming messages, we invoke a stored procedure on NRDB side and then process the result according to the nrdb message type code.

NRDBMessageTypeHandlerWithoutConnection

Essentially a clone of the NRDBMessageTypeHandler (see above) with all connection details removed. The engine will read unhandled messages from the NRDB_MESSAGE_TYPE table and handle them according to their code. There is no distinction between incoming and outgoing messages, in each case the message’s processResult() method is invoked directly. No NRDBMessageSender is created and no stored procedures are invoked.

The purpose of this engine is to test the NRDB process. To use the engine from a test environment, a new entry can be inserted manually into the NRDB_MESSAGE_TYPE table. Note that it is important to insure that the details of this entry are correct according to the expected outcome of processing these messages. For example, if an entry is created with code 105, that message’s processResult() function will create a new NpExportFlowNO object and invoke the NP_EXPORT workflow.

Note that for this engine, the mandatory engine parameters are ENGINE_KEY and engine_name.