Hello Folks,
We have SAP running on SQL Server. We have configured HA using Availability Groups with Listeners. Since SAP is HA aware and works on listener based Always On Configuration, it gives us the flexibility to do a Synchronous replication using automatic failover. Also we switch between Active and Passive Instances every maintenance window.
Now some which we are unable to do on a regular basis is a DBCC check as some of our databases are very large and a DBCC check puts enormous load on the server causing performance issues. Unfortunately we are unable to find any window where the load is less which can allow us to run these checks. We do with Physical Only for now but I want to run full DBCC checks as these are very critical applications.
I read that with SQL Server 2012, DBCC checks are possible on the passive node if we make them readable. I have the following concerns.
- We have Sync replication, will DBCC put a lock on the transaction logs causing the transaction log to grow and the system getting out of sync. If yes, how does this locking work, will it be only on the table or object for which it is doing a DBCC or nothing will replicate. I know I can test this on a test system but there is no way for me to replicate the transactions we hit in production and I will hate any surprise in production.
- I will switch active to passive every month so both the nodes are in sync. but do you see any other issues with this practice.
- Anything else you think will be useful here.
Yogi