Recently, I was pulled into a gig to help troubleshoot an windows failover cluster service issue that was hindering an availability group. Just to give a little background information its a two node windows cluster with two replicas the availability groups are using synchronous mirroring. Once, this was resolved we had a critical database that was behind on synchronization because one of the two replicas (cluster node) was down. This lead to the following question. When will my replica by synchronized?
This question was easy to answer with database mirroring. We could pull up the database mirroring monitor. We don’t have an database replica monitor GUI tool built into SSMS. Lucky for us, its not that hard with availability groups. We just have to use performance monitor. You will see below there is an perfmon collection called “SQLServer:Database Replica” that comes in handy for us.
Above, you can see that this secondary replica which is back online is synchronizing as its receiving log bytes and the Recovery Queue shown in the performance monitor is also reducing as the synchronization process is catching up. According to MSDN Recovery Queue is the Amount of log records in the log files of the secondary replica that has not yet been redone.