Can a single Witness server monitor 2 clustered environments?

  • 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

  • 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.

    Watch my free SQL Server Tutorials at:
    http://MidnightDBA.com
    Blog Author of:
    DBA Rant – http://www.MidnightDBA.com/DBARant

    Minion Maintenance is FREE:

  • The witness is for database mirroring. The clustered servers monitor each other with a heartbeat to determine if the other is still alive.

  • I assumed he was talking about mirroring. Was I wrong?

    Watch my free SQL Server Tutorials at:
    http://MidnightDBA.com
    Blog Author of:
    DBA Rant – http://www.MidnightDBA.com/DBARant

    Minion Maintenance is FREE:

  • 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

  • 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.

    Watch my free SQL Server Tutorials at:
    http://MidnightDBA.com
    Blog Author of:
    DBA Rant – http://www.MidnightDBA.com/DBARant

    Minion Maintenance is FREE:

  • 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

  • Well again it sounds like we might not be on the same page. The witness I'm talking about is a mirroring witness.

    Watch my free SQL Server Tutorials at:
    http://MidnightDBA.com
    Blog Author of:
    DBA Rant – http://www.MidnightDBA.com/DBARant

    Minion Maintenance is FREE:

Viewing 8 posts - 1 through 7 (of 7 total)

You must be logged in to reply to this topic. Login to reply