5 Replies Latest reply: Dec 5, 2012 12:16 PM by LaserSoft RSS

    RAC One Node vrs Oracle Fail Safe

    Jimbo
      What's the difference between RAC One Node and Oracle Failsafe ?

      To my mind, RAC One Node seems to be basically the same active / passive cluster model as FailSafe ( some refer to it as cold failover by RAC One Node ). Failsafe is specifically for the Windows environment ( as in integrates with Microsoft Cluster Services ).

      Does RAC One Node, operate in the same way as RAC in that it can sit on top of any cluster solution ( i.e. Oracle Clusterware or any other 3rd party clustering solution ) ? If so then I am thinking that RAC One Node on top of Microdoft Cluster Server effectively gives the same thing as Fail Safe !

      Of course it may be that RAC One Node canot sit on top of Microsoft Cluster Services ?

      Any thoughts ?
        • 1. Re: RAC One Node vrs Oracle Fail Safe
          Levi Pereira
          From my point of view considering HA, here's the main difference between these two products:

          Oracle Fail Safe
          * Could Failover

          Oracle RAC One Node:
          * Could Failover
          * Omotion ("Hot" Failover) (it's a transparent failover even using One Instance)

          The Omotion allows you to move the Oracle RAC One Node instance from one node to another in the cluster. There are several reasons you may want to move the instance such as the node is overloaded so you need to balance the workload by moving the instance, or you need to do some operating system maintenance on the node however you want to eliminate the outage for application users by moving the instance to another node in the cluster.


          http://www.oracle.com/technetwork/products/clustering/overview/ug-raconenode-2009-130760.pdf?ssSourceSiteId=otncn
          • 2. Re: RAC One Node vrs Oracle Fail Safe
            Jimbo
            Seems to make sense. To ask an obvious question that I think I know the answer to -

            If you have Instance A & B on Server Node 1 ( in a 3 node cluster ), with RAC One Node could you on failure of Server Node 1, move Instance A to Server Node 2 and Instance B to Server Node 3 ( or do both have to move to the same node because they started off sharing a node ? )

            Jim
            • 3. Re: RAC One Node vrs Oracle Fail Safe
              Levi Pereira
              Jimbo wrote:
              Seems to make sense. To ask an obvious question that I think I know the answer to -

              If you have Instance A & B on Server Node 1 ( in a 3 node cluster ), with RAC One Node could you on failure of Server Node 1, move Instance A to Server Node 2 and Instance B to Server Node 3 ( or do both have to move to the same node because they started off sharing a node ? )
              With RAC one node you MUST have only one Instance Active a time. (during Failover (omotion) you will see in short time two instance target/destination one in each node to perform live migration).

              About where instance will run: This depend of your ServerPool.
              If you serverpool have configured (e.g node1,node2,node3) the instance can move to any node or you can specify the node in that serverpool

              With RAC One Node instances "float around" inside the Serverpool. (i.e they are not exclusive from a node, but it's exclusive from serverpool)

              Defining the number of servers or instances preferred for the application. Oracle Clusterware automatically allocates resources up to the number specified as long as they are physically available, and relocates a resource to another node as necessary.

              http://docs.oracle.com/cd/E11882_01/install.112/e25666/srvpool.htm#BHBBGEIE

              Regards,
              Levi Pereira
              • 4. Re: RAC One Node vrs Oracle Fail Safe
                Jimbo
                Thanks for the info Levi
                • 5. Re: RAC One Node vrs Oracle Fail Safe
                  LaserSoft
                  Hi

                  Major difference is :

                  1. Oracle FailSafe is only available for Windows Operating System not for other Operating Systems. It works with MicroSoft Cluster Services (MSCS)
                  2. Oracle RACOne Node can implement on any Operating System.
                  3. In Future, easy to migrate to RAC-Node (Provided Oracle RAC License has to purchase additionally)

                  Thanks
                  LaserSoft