3 questions on database mirroring

  • Has anyone received an answer on the "Alter Database 1456" error. I am having the same problem. It appears as my databases are mirrored but the witness connection fails.

  • I've helped out a few people in person with this problem, and every time it came down to there being some configuration that was wrong on their end.

    My advice is to check everything.

    1. Make sure the witness is litening on the assigned port. Remember that if you telnet into the port, that only shows that soemthing is listening on the port. It may not be your endpoint. Use netstat to verify.

    2. Make sure that the endpoint is started and in the role of either witness or all.

    3. Make sure that there are no other endpoints on any instances on the server trying to use the same port.

    4. Make sure that remote conenctions are enabled and that the tcp protocol is enabled.

    5. Make sure that the servers can ping each other and correctly resolve the FQDN's.

    6. Check the hosts file on all servers for any entries with the other servers' names or FQDN.

    7. Make sure the port is not being blocked by the firewall.

    8. Make sure all servers are using the same domain account for the SQL Server service account or explicit permissions have been granted to connect to the endpoint or certificate authentication has been set up.

    9. If using certificate authentication make sure that the certificates are not expired.

    10. Make sure all endpoints are using the same encryption protocol.

    11. Check network latency between the instances.

    Also when posting about this issue, please be sure to indicate what your SQL builds are.


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