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GertjanA's avatar
GertjanA
Moderator
7 years ago

EV12.3 - SQL AlwaysOn - question on configuration

Hello all,

Initially I as glad to read I could use AlwaysOn in combination with EV, even if it ment a bit additional work for the DBA's. During pre-configuration however, we ran into issues with the Deployment Scanner not being able to consistently connect to the listener. After thorough reading, it turns out the SQL best practices guide has this line: 

Do not employ Multi-Subnet Failover clustering; this is currently not supported.

Guess what....

We have 2 Datacenters. Each has a 2 node SQL cluster. The cluster in the active DC was supposed to 'always on' with the passive DC. The listener however is defined twice. one ip is online on sql, 1  is offline. DNS however has 2 entries. As you understand, Deployment Scanner connects using DNS, which fails very now and then due to incorrect lookup.

We're now looking at reconfiguring SQL (using mirroring), but still prefer a HA/AO setup.

I have been thinking about using the ip-address of the active DC, that however would result in having a custmo (most likely not supported) setup.

The question therefor is: when will this be in the product? Is it on the roadmap? Will it be EV13/14, or perhaps 12.4 or 12.5

Any response from a Veritas guru will be appreciated.

  • DanIhrig's avatar
    DanIhrig
    Level 2
    7 years ago

    Hi Gertjan,

    A DBA at a client site used this solution: The AAG may be configured without Multi-Subnet Failover (even though the servers are different DCs). Only impact is that it will take an extra few minutes during failover as the clients must wait longer for the listener DNS entry to update.

    -Dan

     

  • CConsult's avatar
    CConsult
    Moderator
    7 years ago

    Hello Gertjan,

    https://www.veritas.com/support/en_US/doc/11765145-121370456-0/v111469849-121370456

    Using SQL AlwaysOn availability groups

    Enterprise Vault supports SQL AlwaysOn availability groups. You can use the procedures described in this chapter to implement availability groups in your Enterprise Vault environment.

    Before you implement SQL AlwaysOn availability groups, see the recommendations in the Enterprise Vault SQL Best Practices Guide on the Veritas Support website:

    http://www.veritas.com/docs/000021697

    page 43 ff

    • GertjanA's avatar
      GertjanA
      Moderator
      7 years ago

      Hello CC.

      If you look at that last guide (SQL guide for 12.3), you will see this statement on page 44.

      Do not employ Multi-Subnet Failover clustering; this is currently not supported.

      As I have multisubnet, I cannot use A-O. I do not want to run an unsupported configuration as you understand.

      We've asked Veritas support, and they came back with "it is on the roadmap, it is unknown when or in which version it will be available, escalate to your BCAM". that's what we did :-)

      • CConsult's avatar
        CConsult
        Moderator
        7 years ago

        now I see your commentary from before :)

        So the problem is, that you have two listener IPs/Names and EV does not always resolve the active cluster.

        Well if it is not supported...but nice to know its on the roadmap.