What is the advantage of creating an Application VIP ?
I know that an application VIP is a cluster resource which can be failover to surviving nodes.
Why do we actually need it ? By default, if a node crashes, all connections will go to the surviving node.
Application VIP is basically use to manage third party web based application through clusterware. Below is a sample example of managing Apache service using clusterware:-
1) Create a application VIP resource
crs_profile -create myappvip -t application -a $ORA_CRS_HOME/bin/usrvip -o
2) Register the resource with clusterware
3) Create a cluster type resource to manage your application like ACTION_SCRIPT is required to start,stop, clean and check the application availability. Here is also mentioned the resource dependency with application VIP.
crsctl add resource myapache -type cluster_resource -attr "ACTION_SCRIPT=/usr/local/bin/apache.scr,PLACEMENT='restricted',HOSTING_MEMBERS='host01 host02',CHECK_INTERVAL='30',START_DEPENDENCIES='hard(myappvip)',STOP_DEPENDENCIES='hard(myappvip)',RESTART_ATTEMPTS='2'"
4) Start the myapache resource
crsctl start res myapache
Let's say apache service get started on host01..in case if host01 goes down due to some failure in that case myapache will be failover to another node along with the application VIP.
From 11g release 2 onwards you can use appvipcfg interface to create the application VIP resource and you can also assign server pool instead of using node name.
Reference :- http://docs.oracle.com/cd/E11882_01/rac.112/e16794/crschp.htm
Edited by: rarain on May 28, 2013 5:56 PM
You do not need create an application vip or resource if you are just managing database resources. Since Oracle provides full clusterware functionality, it can be used just like any other clusterware in market for managing other non db resources as well.