Mirroring Failover/Failback

I have been using Mirroring now for a while and put the system into
production now after applying SQL sp 1.
We have a setup with a witness, principal and mirror with certificates (the
witness is on a webserver in a different domain, so we can't use integrated
security).
Automatic failover works fine if we take down the principal. But when the
principal is up and running again, no automatic failback occur. If this by
design, or is there something I've missed out in the configuration?
Per SchjetneThe roles for mirroring are soft roles. So, you cannot define a preferred no
de (like you can for a
cluster). If you want to fail back, you have to ask for it (ALTER DATABASE).
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Per Schjetne" <newsuser1@.gdconsult.no> wrote in message
news:uo3Ac4caGHA.3736@.TK2MSFTNGP04.phx.gbl...
>I have been using Mirroring now for a while and put the system into product
ion now after applying
>SQL sp 1.
> We have a setup with a witness, principal and mirror with certificates (th
e witness is on a
> webserver in a different domain, so we can't use integrated security).
> Automatic failover works fine if we take down the principal. But when the
principal is up and
> running again, no automatic failback occur. If this by design, or is there
something I've missed
> out in the configuration?
> Per Schjetne
>|||"Per Schjetne" <newsuser1@.gdconsult.no> wrote in message
news:uo3Ac4caGHA.3736@.TK2MSFTNGP04.phx.gbl...
>I have been using Mirroring now for a while and put the system into
>production now after applying SQL sp 1.
> We have a setup with a witness, principal and mirror with certificates
> (the witness is on a webserver in a different domain, so we can't use
> integrated security).
> Automatic failover works fine if we take down the principal. But when the
> principal is up and running again, no automatic failback occur. If this by
> design, or is there something I've missed out in the configuration?
Sorry, there isn't an option for automatic failback. You will have to do
that manually.
Russ Kaufmann
MVP - Windows Server - Clustering
ClusterHelp.com, a Microsoft Certified Gold Partner
Web http://www.clusterhelp.com
Blog http://msmvps.com/clusterhelp|||If you think about it, failing back will cause all client connections to be
dropped again so you probably don't want SQL Server to decide when is a good
time to fail back. It's probably much better if you pick a time when the
change won't affect too many users.
This posting is provided "AS IS" with no warranties, and confers no rights.
Use of included script samples are subject to the terms specified at
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"Per Schjetne" <newsuser1@.gdconsult.no> wrote in message
news:uo3Ac4caGHA.3736@.TK2MSFTNGP04.phx.gbl...
>I have been using Mirroring now for a while and put the system into
>production now after applying SQL sp 1.
> We have a setup with a witness, principal and mirror with certificates
> (the witness is on a webserver in a different domain, so we can't use
> integrated security).
> Automatic failover works fine if we take down the principal. But when the
> principal is up and running again, no automatic failback occur. If this by
> design, or is there something I've missed out in the configuration?
> Per Schjetne
>|||I agree on that. Is there a way to query any system tables telling me which
database is acting as principal vs mirror? Is the witness aware of this, or
is it just monitoring which server is replying, being able to do a failover?
"Roger Wolter[MSFT]" <rwolter@.online.microsoft.com> wrote in message
news:%23J5%23JJhaGHA.1192@.TK2MSFTNGP04.phx.gbl...
> If you think about it, failing back will cause all client connections to
> be dropped again so you probably don't want SQL Server to decide when is a
> good time to fail back. It's probably much better if you pick a time when
> the change won't affect too many users.
> --
> This posting is provided "AS IS" with no warranties, and confers no
> rights.
> Use of included script samples are subject to the terms specified at
> http://www.microsoft.com/info/cpyright.htm
> "Per Schjetne" <newsuser1@.gdconsult.no> wrote in message
> news:uo3Ac4caGHA.3736@.TK2MSFTNGP04.phx.gbl...
>|||There's an event that you can monitor to be notified when the state changes.
The sys.dm_database_mirroring view can be used to determine the mirroring
state of all the databases of an instance. The
sys.dm_database_mirroring_witnesses can be used from the witness to see
which server is the primary.
This posting is provided "AS IS" with no warranties, and confers no rights.
Use of included script samples are subject to the terms specified at
http://www.microsoft.com/info/cpyright.htm
"Per Schjetne" <newsuser1@.gdconsult.no> wrote in message
news:OLn03SiaGHA.2368@.TK2MSFTNGP03.phx.gbl...
>I agree on that. Is there a way to query any system tables telling me which
>database is acting as principal vs mirror? Is the witness aware of this, or
>is it just monitoring which server is replying, being able to do a
>failover?
>
> "Roger Wolter[MSFT]" <rwolter@.online.microsoft.com> wrote in message
> news:%23J5%23JJhaGHA.1192@.TK2MSFTNGP04.phx.gbl...
>|||That's not exactly correct.
The reason it did not failback, is because that database is no longer the
principal. Failover causes a role reversal. When it fails over to the
mirror, that database is promoted to a principal and begins serving the
database. When the other database comes online, its role is automatically
demoted to mirror and the transactions start flowing back to it.
Mike
http://www.solidqualitylearning.com
Disclaimer: This communication is an original work and represents my sole
views on the subject. It does not represent the views of any other person
or entity either by inference or direct reference.
"Tibor Karaszi" <tibor_please.no.email_karaszi@.hotmail.nomail.com> wrote in
message news:eDV9lIeaGHA.4936@.TK2MSFTNGP05.phx.gbl...
> The roles for mirroring are soft roles. So, you cannot define a preferred
> node (like you can for a cluster). If you want to fail back, you have to
> ask for it (ALTER DATABASE).
> --
> Tibor Karaszi, SQL Server MVP
> http://www.karaszi.com/sqlserver/default.asp
> http://www.solidqualitylearning.com/
>
> "Per Schjetne" <newsuser1@.gdconsult.no> wrote in message
> news:uo3Ac4caGHA.3736@.TK2MSFTNGP04.phx.gbl...
>|||Thanks! Just what I needed. By the way, the correct tablename is:
sys.database_mirroring_witnesses
Per :-)
"Roger Wolter[MSFT]" <rwolter@.online.microsoft.com> wrote in message
news:%23bsLDGkaGHA.3720@.TK2MSFTNGP03.phx.gbl...
> There's an event that you can monitor to be notified when the state
> changes.
> The sys.dm_database_mirroring view can be used to determine the mirroring
> state of all the databases of an instance. The
> sys.dm_database_mirroring_witnesses can be used from the witness to see
> which server is the primary.
> --
> This posting is provided "AS IS" with no warranties, and confers no
> rights.
> Use of included script samples are subject to the terms specified at
> http://www.microsoft.com/info/cpyright.htm
> "Per Schjetne" <newsuser1@.gdconsult.no> wrote in message
> news:OLn03SiaGHA.2368@.TK2MSFTNGP03.phx.gbl...
>