August 11, 2008 at 6:38 am
I have a question about setup. If I have two server environments, both clustered for failover, can a single witness server monitor both? I have 2 2-way boxes clustered and 2 4-way boxes as separate sql environments. I can get a single 2 way box to host the witness server for these. Will I be setting up 2 witness servers on the one single box, or will I have a single witness server monitor 2 environments?
Also, can the witness server be virtualized? Good idea or not?
Thanks
Bob
Bob
Not a downstroke, fistpicker
August 11, 2008 at 9:09 am
Well your witness shouldn't know anything at all about the clusters so that doesn't matter. And y, a server can witness as many scenarios as you need it to. And as long as the environment is very stable, I think virtual is a fine way to go for your witness.
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August 11, 2008 at 9:23 am
The witness is for database mirroring. The clustered servers monitor each other with a heartbeat to determine if the other is still alive.
August 11, 2008 at 9:30 am
I assumed he was talking about mirroring. Was I wrong?
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August 11, 2008 at 10:00 am
No, I was under the assumption that the witness server monitored the clusters and provided the heartbeat. I knew it was for mirroring, but I thought it also was for failover. They just handle each other for failover?
Bob
Not a downstroke, fistpicker
August 11, 2008 at 10:09 am
No, the witness is just there to prevent the splitbrain scenario where each node could think it's supposed to be the primary. The witness is a tiebreaker of sorts.
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August 11, 2008 at 11:11 am
Explain the "splitbrain" thing a bit if you can.
The goal is to run a 4 way that can fail over to another 4 way. That's the extent of the high availabilty desire. No replication or mirroring I guess. Does the witness server play a role in that setup, and can it handle 2 environments, say a prod1 and prod2 clusters housing different applications?
Bob
Not a downstroke, fistpicker
August 11, 2008 at 11:39 am
Well again it sounds like we might not be on the same page. The witness I'm talking about is a mirroring witness.
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