RAC Services in 11gR2

Question

Hi,
Need clarification on services.
I've a 2node RAC 11gR2.
I want to configure service for example srvc1 on both node1& node2 with the following features.
On node1 - for srvc1 preferred instance is inst1 and available instance is inst2 and failover type is select.
On node2 - for same srvc1 service preferred instance is inst2 and available instance is inst1 and failover type is select
and as well load balance need to done between node1& node2.
So that what ever session connected to node1 will failover to node2 and vice versa and load balance will be happened.
In this way is it possible to configure the same service on 2 nodes?
Thanks,
Sandeep

Answer 1

Here is a good place to start: http://docs.oracle.com/cd/E11882_01/rac.112/e16795/hafeats.htm
A service created as -r node1,nod2 will load balance **AND** fail over to the other node automatically - regardless of which instance you connected initially. If you are using SCAN, again don't try to something manually that is already being done for you by Oracle. Most that try to out-think SCAN usually get it wrong.
Some light reading:
http://www.oracle.com/technetwork/database/features/availability/maa-wp-11gr2-client-failover-173305.pdf
From:
http://docs.oracle.com/cd/E11882_01/network.112/e10836/concepts.htm
"Due to dynamic service registration, a listener is always aware of all instances and dispatchers regardless of their location. Depending on the load information, a listener decides which instance and, if shared server is configured, to which dispatcher to send the incoming client request.
In a shared server configuration, a listener selects a dispatcher in the following order:
Least-loaded node
Least-loaded instance
Least-loaded dispatcher for that instance
In a dedicated server configuration, a listener selects an instance in the following order:
Least-loaded node
Least-loaded instance
If a database service has multiple instances on multiple nodes, then the listener chooses the least-loaded instance on the least-loaded node. If shared server is configured, then the least-loaded dispatcher of the selected instance is chosen.
"