Re: Oracle RAC and VIPs

  • From: "Nadeem M. Khan" <nadeem.m.khan@xxxxxxxxx>
  • To: paul.baumgartel@xxxxxxxxxxxxxxxxx
  • Date: Thu, 10 Jul 2008 22:28:23 +0400

On Thu, Jul 10, 2008 at 9:03 PM, Baumgartel, Paul
<paul.baumgartel@xxxxxxxxxxxxxxxxx> wrote:
> If the VIP comes up on another node, doesn't the attempt to connect to that
> (virtual) IP translate to a connect to the other node?  If not, how exactly
> is the failure detected right away?

When the VIP fails over to another node, it is not supposed to belong
to that node. The MAC address and listener configuration  of that node
do not match the VIP. This is detected by the client immediately and a
connection reset (negative ack) occurs. The client then tries to
connect to the next available node.

If there was no VIP, the client would have taken around 10 mins to
detect a connection timeout as there would have been no reset signal.
This is to say that the purpose of the VIPs is not just failover, but
*fast* failover.


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