Oracle - RAC

[KapilRaj]

Guys,

I am reading the documentation of RAC. Is it true that RAC will not have a floating IP address like the traditional HA products ? for example service IP on a SG ?.

RAC documentation says that I need to create a tnsnames.ora on the client pointing to all the cluster nodes in a RAC cluster. I did not see a section where they mentioned, I can also have a floating IP address or so.

Regards,

Kaps

[Jeff_Traigle]

Judging by our configurations for 10g and 11gR2, you don't have floating IP addresses with RAC. If you're running active-active, you really can't have one address floating. Each node has it's own virtual IP address so the clients would need to know the VIPs for all of the nodes in the RAC cluster for any given database.

[KapilRaj]

Hmm .. Thank you.

I thought there would be a manager kind of system who would redirect client requests.

Thank you for the feedback.

[Kapil Jha]

RAC is different, its tnsnames.ora file which actually take care of failover.

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1021875

All the cluster members are eager to handle the oracle request at any point of time if smthing goes wrong with one machine and its taken care by tnsnames.ora file.

BR,
Kapil+

[WayneHP]

tnsnames.ora on the client will handle transparent failover. Oracle apps sitting on top of DB need to be aware for maximum benifit of this feature.

Example.

A users executes a long query and in the middle of the query the node serving the DB loses connection. Tranparent failover will move the connect and reexecute the query. In the sqlplus sessions this is not displayed clearly as the query picks up where the last one left off after the next node in RAC you specified in the tnsnames.ora catches up with the query.