The journal switch mode makes intermittent use of the network communications for the transmission of journals and control information. The journal is transferred to the secondary when the journal is complete and writing switches to a new journal.
The benefit is to provide journal shipping with a minimum demand on your network and processor capacity. You can control journal file size by using the
A journal switch secondary is synchronized when it is replaying the last complete journal. As long as a secondary is connected to the primary and communications are working, the secondary knows the current journal on the primary so that it can accurately report the state of the secondary in relation to the primary.