When a connection error occurs while the PowerCenter Integration Service is acknowledging a checkpoint in the source, the PowerCenter Integration Service fetches and acknowledges the messages in the current checkpoint. The session fails if the PowerCenter Integration Service does not find any message to acknowledge.
If 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 the messages in the current checkpoint.