Failover Clusters on SQL 2000 or 2005

Discussion of open issues, suggestions and bugs regarding usage of dbExpress drivers for SQL Server in Delphi and C++Builder
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sparkz
Posts: 9
Joined: Thu 15 May 2008 17:01

Failover Clusters on SQL 2000 or 2005

Post by sparkz » Thu 15 May 2008 17:11

Can someone tell me if this driver will work with SQL Server (2000 or 2005) when failover clustering is implemented on the database.

Microsoft documentation talks about cluster aware drivers but I don't know if that applies to dbExpress?

I have a user which has SQL Server 2000 with failover clustering and things seem to stop working when the failover switches databases. This could be a setup issue but I just need to know if there is anything about the driver which would prevent this from working or if any parameters are missing?

Hope that makes sense.

Thanks

sparkz
Posts: 9
Joined: Thu 15 May 2008 17:01

Post by sparkz » Thu 15 May 2008 23:03

To put it simpler.

Does the fact that dbexpsda.dll uses sqloledb.dll mean that it complies with the Microsoft Failover Clustering standards/requirements?

Or isn't dbExpress compatible?

Thanks

Antaeus
Posts: 2098
Joined: Tue 14 Feb 2006 10:14

Post by Antaeus » Fri 16 May 2008 08:51

As far as I know, Failover Clustering is transparent for clients when connecting through a Virtual Server.
DbxSda supports setting the Failover Partner for Database Mirroring. There is the information about setting this option in the Readme.html file that is located in the DbxSda installation directory.

sparkz
Posts: 9
Joined: Thu 15 May 2008 17:01

Post by sparkz » Fri 16 May 2008 09:56

Thanks for that. I assume it must be a failover setup issue.

sparkz
Posts: 9
Joined: Thu 15 May 2008 17:01

Post by sparkz » Mon 09 Jun 2008 10:38

From what I can gather here is that the Microsoft drivers must be doing something which the Core Labs ones aren't. It's odd the Microsoft web site specifically mentions "cluster aware" drivers.

Our developing partner, who just uses purely Microsoft technology, doesn't have any problems when a failover switch is made. We, using the dbExpress driver, do though.

We seem to end up taking to an empty database. No errors are generated and subsequent queries just return no data?!

The "Failover Partner" you mention is for a different setup and as far as I'm aware isn't applicable here.

Is Core Labs stance here that it's just happy to have non cluster aware drivers? Whatever that means! :?

Antaeus
Posts: 2098
Joined: Tue 14 Feb 2006 10:14

Post by Antaeus » Thu 12 Jun 2008 07:04

We will deeply investigate this issue in the nearest time.

sparkz
Posts: 9
Joined: Thu 15 May 2008 17:01

Post by sparkz » Thu 12 Jun 2008 09:58

Thanks for that

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