SCAN Listener and Virtual IP

 Scan Listener :

* we add or remove a node from cluster,it was required to changes the connection setting in client
  ( applicaton )  by configuring the connection using SCAN NAME this problem is eliminated.

* Irrespective number of nodes oracle recommands to have 3 SCAN IP's and one SCNA NAME which be decide to any of the SCAN IP i round rabin manner.

* the Benifit is clients using SCNA do not need to change if you add or remove nodes in the cluster.

* SCAN is a single network name that resolves theree different IP's registered in DNS or GNS.

* if we are using DNS scan listener ip's will store in

  /etc/resolv.conf


* how to start the scan listener

   $ srvctl start scan_listener -i 2


VIP ( Virtual IP ) :

* VIP is a alternate VIP address assigned to each node,

* In a cluster during a node failure vip of the  failed nodes moves to surving node and relay to                  the  applicaton,

* how to start the vip

    $ srvctl start vip -i Vip_name -v
                                             

No comments:

Post a Comment