Cluster Hardware Layout

Question

Hello;
          We are in the process of setting up a Weblogic cluster with 3 Solaris
          servers all running Weblogic 5.1 . Somone has suggested that we isolate
          these servers on there own subnet or vlan as the Weblogic servers become
          very "chatty". He also recommneded the following:
          That each box have a direct connection to EMC shared disk. The EMC shared
          disk will be presented as a logical volume to all servers in cluster. (this
          is network connection #1)
          Each server in cluster should have a Gigabit ethernet interface that is only
          for communication between the servers in the cluster (i.e.- multicasting
          etc..) (this is network connection #2)
          Each server would have a public Gigabit ethernet interface that is listening
          for client requests. ( this is network connection #3)
          My questions are:
          1. Is this configuration possible within the scope of weblogic clustering?
          2. Is it practical?
          3. If the answers to the above questions are "yes" how can I tell the
          different weblogic instances to listen for multicast broadcasts and to
          perform memory replications across connection #2 instead of connection #3.
          4. EMC has told me that we can carve out some disk space and present it to
          multiple machines to be shared disk space, has anyone else done this with
          weblogic?
          Thanks for your time.
          -Bob
          

Answer 1

          "Bob Olson" <[email protected]> wrote:
          >Hello;
          >
          >We are in the process of setting up a Weblogic cluster with 3 Solaris
          >servers all running Weblogic 5.1 . Somone has suggested that we isolate
          >these servers on there own subnet or vlan as the Weblogic servers become
          >very "chatty". He also recommneded the following:
          If you are using a switch which has many other hosts and servers connected to it besides the 3 Weblogic Servers
          you will want to isolate Multicast traffic by putting the 3 WebLogic servers in a separate VLAN. If you have the
          3 servers connected to a shared medium such as bus network topology you will probably want to use VLSM and
          routers to create a seperate subnet for the 3 servers (This will isolate Multicast traffic to just the 3 WebLogic
          servers) vs. the whole network receiving the Multicast traffic.
          >
          >That each box have a direct connection to EMC shared disk. The EMC shared
          >disk will be presented as a logical volume to all servers in cluster. (this
          >is network connection #1)
          This sounds like a Storage Area Network (SAN) type solution. Hopefully it will also have transparent
          failover and backup.
          >
          >Each server in cluster should have a Gigabit ethernet interface that is only
          >for communication between the servers in the cluster (i.e.- multicasting
          >etc..) (this is network connection #2)
          This might be overkill for three machines. Most of the initial traffic for Multicast is when the
          WebLogic servers start up. After that, there are occational hearbeats that are sent out.
          Hot deploying and undeploying objects could increase this traffic but it probably would not come close
          to utilizing 1% of the Gigabit ethernet pipe.
          >
          >Each server would have a public Gigabit ethernet interface that is listening
          >for client requests. ( this is network connection #3)
          >
          From my understanding a single instance of WebLogic can only bind to a single IP address.
          I don't think you need 3 physical connections. If you load was great I probably would use
          single Gigabit switch with each of the following connected to a port on the switch:
          SAN (EMC), WebLogicServer1 ,WebLogicServer2 ,WebLogicServer3, etc.
          >My questions are:
          >
          >1. Is this configuration possible within the scope of weblogic clustering?
          >2. Is it practical?
          >3. If the answers to the above questions are "yes" how can I tell the
          >different weblogic instances to listen for multicast broadcasts and to
          >perform memory replications across connection #2 instead of connection #3.
          I don't think this is possible currently
          >4. EMC has told me that we can carve out some disk space and present it to
          >multiple machines to be shared disk space, has anyone else done this with
          >weblogic?
          Haven't done this but read about it.
          >
          >Thanks for your time.
          You welcome.
          >
          >-Bob
          >
          >
          Hope This Helps,
          Abraham Kang