5 Replies Latest reply: Dec 5, 2012 7:50 AM by Levi Pereira RSS

    Cluster of SCAN IP required ?

    user8665771
      Hi,



      In Oracle 11g RAC, by default 3 scan IP will come if i am going to configure 2 node RAC.

      If i want to connect DB from application server like weblogic, Then i can give one IP only in weblogic ODBC configuration.

      So is it require to configure IP cluster of SCAN IP ?

      or can i use 1 SCAN IP ?


      Please clarify me.
        • 1. Re: Cluster of SCAN IP required ?
          GauravAhuja
          Hi,

          First of all Scan Ip's are used for load balancing.

          Scan Stands for Single client access name, means all of your xyz@example.com need to be resolved three Ip addresses By Dns.

          You will pass xyz@example.com instead of hostname and any Ip to your connection String for connectivity.

          When one system in your cluster will goes down, that ip will moves or shift to remaining node and no where you need to change any configuration at the time of down. All your connections and requests will be redircted to New Node.

          and All three Scan Ip should be resolvable by DNS and one thing more if you use single scan ip then system will be overloaded where Scan Ip will work because all requests first come to that System and then move forward.

          Regards
          Gaurav
          • 2. Re: Cluster of SCAN IP required ?
            Victor Armbrust
            For SCAN you should use 3 IP address configured on a DNS server.

            You can use an IP address (eg: VIP) to connect to your database, however, SCAN would be need for RAC installation

            THe best pratice is to USE SCAN to make the TNS connections
            • 3. Re: Cluster of SCAN IP required ?
              Billy~Verreynne
              user8665771 wrote:

              In Oracle 11g RAC, by default 3 scan IP will come if i am going to configure 2 node RAC.
              You need only a single IP as SCAN address. Using 3 IP addresses is a recommendation. Not mandatory.
              If i want to connect DB from application server like weblogic, Then i can give one IP only in weblogic ODBC configuration.
              So is it require to configure IP cluster of SCAN IP ?
              or can i use 1 SCAN IP ?
              Yes, you can use a single IP address as SCAN address. Yes, a SCAN hostname and IP are mandatory - and makes client's network access configuration a lot easier.

              Yes, client connections to the cluster should be via the SCAN hostname. (clients should typically not directly use IP addresses)
              • 4. Re: Cluster of SCAN IP required ?
                nnarimanov
                SCAN can include max 3 IPs. In my organization we define SCANs on 2 IPs
                • 5. Re: Cluster of SCAN IP required ?
                  Levi Pereira
                  nnarimanov wrote:
                  SCAN can include max 3 IPs. In my organization we define SCANs on 2 IPs
                  not max ... recommended ... you can configure more than 3