Results 1 to 9 of 9
  1. #1
    Join Date
    Jan 2008
    Posts
    96

    Unanswered: active/active cluster in db2

    Hi Folks,

    I have been searching on the internet on how to set up an active/active cluster in db2 similar to Oracle RAC and haven't been able to find a straight answer. Can this be done? If yes, do I need additional software to take care of the database load balancing. I was reading about xkoto's GridSCALE software, is anybody using that?

    Will appreciate your help.

    Thanks

  2. #2
    Join Date
    Jan 2008
    Posts
    96
    Has anybody worked on setting up an active/active cluster in DB2?????

    Thanks

  3. #3
    Join Date
    Aug 2001
    Location
    UK
    Posts
    4,650
    Look through the forum ... within the last week or two, there was a discussion about HA and Marcus_A had mentioned a few lines about xkoto's products.
    Visit the new-look IDUG Website , register to gain access to the excellent content.

  4. #4
    Join Date
    Jan 2008
    Posts
    96
    Thanks Sathyaram_s.

    If anybody else is also looking for that thread:

    http://www.dbforums.com/db2/1635488-...-solution.html

    This means that there is really no way in DB2 to achieve a HA solution with NO downtime at all....

  5. #5
    Join Date
    Feb 2009
    Location
    Germany
    Posts
    23
    Hallo rangupt,

    I think xkoto is not the same as Oracle RAC. RAC has one database and has SGA distributed between the cluster nodes. If data buffer is already in SGA the other node need not to read this buffer from the database file. It reads it from other cluster cache with interconnect. In xkoto each node has its own database. It is mirroring.

  6. #6
    Join Date
    May 2003
    Location
    USA
    Posts
    5,737
    DB2 does not have the equivalent of RAC clustering for scalability (of course RAC doesn't scale very well for OLTP because of the distributed lock manager, but that is another issue). In DB2 clustering for reliability is done with HADR, which is superior to RAC, since RAC has a single point of failure on the shared disk sub-system (and usually the network).

    One thing to keep in mind is that you only need to license DB2 for 100 PVU's on the HADR standby server (which is the equivalent of 1 dual core CPU), regardless of how many CPU's are on the machine.

    Xkoto is a 3rd party tool that provides clustering for reliability and scalability, but it only provides scalability on Select statements. Inserts, Updates, and Deletes are single threaded, whereas Selects can be distributed out to any available server in the gridscale cluster (you usually need a minimum of 3 servers for high availability/scalability and a minimum of 2 if scalability is the only concern and you have maintenance window). Xkoto is somewhat complicated, and reports are that it is not completely bug-free, but it does work well if you have OLTP and need scalability of a mostly read-only database, and you don't have a data warehouse (in which case DB2 DPF would be a better choice).
    M. A. Feldman
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows
    IBM Certified DBA on DB2 for z/OS and OS/390

  7. #7
    Join Date
    Jan 2008
    Posts
    96
    Can DPF combined with HACMP achieve a similar solution?

  8. #8
    Join Date
    May 2003
    Location
    USA
    Posts
    5,737
    I would forget about using HACMP with DPF. You can get scalability with DPF in certain situations on an OLTP database, but those situations are limited, and I would not recommend it the vast majority of cases. There is a reason why DPF is now called InfoSphere Data Warehouse Edition (no longer called DPF) in V9.5.

    SMP machines can be scaled very large in the same frame, and IBM has a machine (ours is Intel based running Linux) where you can have 4 separate machines effectively linked together as one SMP machine, which pretty much covers all the same failures that a RAC system would protect against. So you can start out with one machine and grow it to 4 machines running regular DB2.
    M. A. Feldman
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows
    IBM Certified DBA on DB2 for z/OS and OS/390

  9. #9
    Join Date
    Jan 2008
    Posts
    96
    Thanks Marcus.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •