Synchronization Phase
In this phase, the --jnlsync process must be run at regular intervals using a cron job. The --jnlsync process has the following steps:
a. If the source has taken a checkpoint since the previous jnlsync operation, copy the source checkpoint to target(s) and rollforward.
Note: This requires the target installation(s) to be shut down.
b. Close the current journal file and create a new file.
c. Copy the new journal files from the source to target(s).
d. Apply the journaled transactions to the target database(s).
Target node databases are in the INCR_RFP state. In this state, user connections are accepted and only SELECT operations are allowed. Update operations are not allowed and will fail. Any target database connections will cause the --jnlsync step to fail with appropriate error messages. This is a soft failure because subsequent invocations will attempt to roll forward all the unprocessed journals. The sync step on the target(s) will connect with the source if there is some window with no user connections. If the source fails, the target will be caught up when it is designated as the new source.
Last modified date: 08/29/2024