SQL Server High Availability Questions

SQL Server High Availability Questions

Question: How replication set up impacts to application performance ?
Answer: No issues with latency. You might see it based on throughput. Never seen replication cause the blocking, but user’s cause it.
Question: have you seen issues with an index rebuild causing a delay in the apply?
Answer: Yes, you may see an impact
Question: How you normally initialize the transactional replication backup or snapshot?
Answer: Normally, snapshot as the start.
Question: what happens when the primary database is restored during replication / log shipping?
Answer: Restoring the publisher during replication depends on when the backup was. If you’ve replicated you’ll have to reinitialize. Maybe restoring the publisher from the subscriber. Restoring a primary in log shipping, you can just pause the agent and restore log files form the secondary and apply to the primary, or just switch roles.
Question: is it possible to setup logshipping from SQL 2000 to SQL 2008, 2008 as Standby ReadOnly .
Answer: 2005 to 2008, yes, 2000 to 2008 yes Question: Question regarding the licensing for log shipping – assuming the secondary is only used for this purpose, are SQL Server licenses required for it and the monitor server?
Answer: You do have to have a licensed copy on all the servers. Check with Microsoft to be sure.
Question: What if during the process of setting up log shipping, one log file goes missing..
Answer: There can’t be holes in the trail. You’d have to go back and re-sync.

Question: Can we have more two or more subscribers for a log shipped DB.

Answer: Not prior to Denali. But in Denali AlwaysOn, yes.
Question: what about LS between 2008 to 2005, is it compatible.
Answer: As a general rule, you can’t restore databases or logs down, meaning to previous versions.
Question: Can a DB have both Mirroring as wells as Log shipping?
Answer: Yes
Question: Can you force the mirror to catch up using asynchronous mode without switching it to synchronous to catch up?
Answer: No
Question: How about setting up mirroring from an active/passive SQL cluster?
Answer: Yes, its work as it’s on virtual instance
Question: peer to peer replication: Does it require SQL Enterprise or will Standard work?

Answer: Peer to Peer is Enterprise only.

One thing to point out is that if you set up mirroring in an environment that does not use sql authentication you need to use certificates and set it up manually through T-SQL