When a connection error occurs while the PowerCenter Integration Service is acknowledging a checkpoint in the source, the PowerCenter Integration Service fetches all messages from the source in the current checkpoint. It fetches the messages in one partition. If the PowerCenter Integration Service detects new messages that it did not process before the connection failed, it processes messages in two transactions. The first transaction includes all the messages which were processed just before the connection failed. The second transaction includes new messages and messages that were not processed.

When the connection error occurs while the PowerCenter Integration Service is fetching messages from the source, the PowerCenter Integration Service issues a real-time commit to the target before it fetches all the messages from the source in the current checkpoint.