Using Q Replication with DB2's HADR

About two years ago, I posted a video showing how to use SQL Replication with HADR.  Lately, I've gotten a bunch of requests to do something similar for Q Replication and HADR.  The good news is that I don't have to :)  there's now a white paper called Using Q Replication with HADR on IBM's developerWorks.  It provides very clear information about best practices, considerations, etc..  I've got a few highlights here.

• Q Replication must always work with the Primary HADR database.

• Have an MQ queue manager for each system running DB2 with HADR.
• • Why? The best practice is to have your queue managers co-located with Q Replication.
  • Your active queue manager will always be the one running where the Primary HADR database is.

• Use WebSphere MQ multi-instance queue managers.
• • This gives you primary and standby queue managers.
  • A shared disk is required.

• Virtual IP addresses (VIPs) cannot be used with MQ or HADR.
• • However, VIPs can be used for client access of DB2.
  • Client reroute or VIP for clients is a decision made independent of Q Replication.

• Tivoli System Automation (TSA) can detect and control the location and operation of Q Replication and MQ.

If you need a picture to help visualize how these fit together, here's one and there are more in the white paper:

I also see two areas I think could use a little more detail:

• Virtual IP addresses
• • Of course, there's a good IBM Technote with information about HADR and VIPs.  That information is applicable to Q Replication with HADR.

• TSA
• • I would like to see more guidance on this.  My understanding is that this may be in the works for an update of the white paper.

Why Use Both Q Replication and HADR?

You can see the answer in the picture above.  A company uses Q Replication to provide continuous availability, Active-Active Databases, or Dual Warehouses across multiple sites.  They then use HADR to provide a local HA or DR solution for one or more of the active sites.   

If those both sound like the same thing to you :)  see the post titled DR, HA, and Continuous Availability - What's the Difference?

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