REPLJNLCLOSED, Replication in jeopardy as journaling for database file ddd. Current region seqno is xxx[XXX] and system seqno is yyy[YYY]
GT.M run-time warning: This message indicates that GT.M turned OFF journaling and switched replication from ON to WAS_ON on the specified database. Other preceding messages identify the cause (for example, lack of disk space while writing to journal file, permissions issue while auto-switching to new journal files,and so on). The message also displays the region and journal sequence numbers. From this point, replicating updates on the primary to the secondary might or might not work depending on the backlog on the primary until replication/journaling gets turned back ON.
First, correct the cause (lack of disk space, permission issues, and so on) that turned journaling OFF.
Execute the MUPIP SET REPLICATION=ON or MUPIP BACKUP REPLICATION=ON command to turn replication (and journaling) ON and switch to a new set of journal files. This command can work while processes are concurrently updating the database and causes GTM to journal subsequent updates in both the journal file and journal pool (rather than only in the journal pool as it does when replication is in the WAS_ON state).
Execute the MUPIP REPLIC -SOURCE -SHOWBACKLOG command. Note down the value of "sequence number of last transaction written to journal pool".
Execute the above command at regular intervals and note down the value of "sequence number of last transaction sent by source server."
If the "sequence number of last transaction sent by source server" is greater than "sequence number of last transaction written to journal pool", it means that the source server successfully sent all journal records during the time interval when journaling was turned OFF. In this case, no further action is required.
On the other hand, if the "sequence number of last transaction sent by source server" is less than "sequence number of last transaction written to journal pool" and reports the same value across repeated SHOWBACKLOG commands, then check the source server log file for any error messages - most likely a NOPREVLINK error from the source server. This means the source server could not locate the corresponding journal records required from the journal files to replicate a particular sequence number and therefore, it failed to synchronize the primary and secondary. In this case, take an online backup of the primary, restore it on the secondary and start the secondary with the UPDATERESYNC qualifier to synchronize the secondary with the primary.