Does SCAN redirect to node-IP or node-VIP?
I have a 2 node 11gR2 RAC cluster with both SCAN and node VIPs configured. Users connect to the SCAN address. The SCAN listener then redirects connections to the node listener. Does it redirect to the node listener via the node's address or the node's VIP address?
Here's why I'm asking. I'm trying to troubleshoot a recurring problem where node2's VIPs (scan and node-vip) keep failing over to node1 every few weeks. CRS logs on node1 say that it thinks (incorrectly) that node2 is inaccesible so it failed over both VIPs (scan and node-vip). Within a minute or so however, node1 can see node2 again without anyone intervening.
Node2 however remains up the entire time and is running normally. Neither the node listener, database instance, or ASM instance show any indication of a problem in their logs.
On node2's database instance however, all sessions have dropped even though the instance remained up. If the SCAN listeners redirect directly to node2, I would not expect this to happen and I can pin the problem down to some network component (switch, NIC, etc). If SCAN redirects to the node-VIP then I would expect this and need to troubleshoot why node1 is incorrectly thinking node2 went down.