The log shipping primary database %s.%s has backup threshold of %d minutes and has not performed a backup log operation for %d minutes. Check agent log and log shipping monitor information.
1. The Message 14420 does not necessarly indicate a problm with logshipping. And this message mostly occur when monitor server is configured. This message generally occured when the differnce between t-log backup and the current time on the monitor server is the greater than the time is set for backup threshold.
2. Ensure the transaction log backup happend on the primary server. If the t-log backup fails then also above error will occur.
3. You may set incorrect value for the backup alert.
4. The date and time of monitor server is different from the date and time of primary server.
5. The logshipping copy job is run on the primary server and may not update the entry in the msdb database at monitor server in the log_shipping_primaries table.
14421 Error :
The log shipping secondary database %s.%s has restore threshold of %d minutes and is out of sync. No restore was performed for %d minutes. Restored latency is %d minutes. Check agent log and logshipping monitor information.
The message doesn't necessarly indicate a problm with logshipping.
1. This may occur restore job on the secondary server is failing.
2. You may set out of sync alert is wrong.