OES2 2 Node Cluster Tie breaker !?
I´ve got a question regarding to OES2 2 Node Clusters and Split Brain Situations.
At one of our customers, i´ve installed a OES2SP3 2 Node Cluster on 2 ESX 4.0 -Servers .
One Node per ESX-Host.
Now I have the following situation, if one of the Nodes (Master or Slave) lose his network connection the master-node always wins. Regardless the master node has a network link or not!
In pursuance of the "The Gory details of Heartbeats, Split Brains and Poison Pills - TID 10053882)
it seems to be a correct behavior.
snip/ This is a special case two-node split brain condition. The node that eats this poison pill has lost the tie breaker because its LAN link was determined to have failed. The other node wins. This logic is available only with the NWCS 1.01 two-node tie breaker patch. Without this patch, the master node will always win whether it has good LAN connectivity or not. /snap
Unfortunately this document is not up to date (NCS 1.01 / NCS106 / Netware 5.1 /Netware 6.0)
but there are no documents about NCS 1.8.x and split brain situation on 2 Node Clusters.
But, I also found a document which told me, that only a Node with Network-Link will win.
We are still at a 2 Node Cluster :-)
So in a split brain situation, the Cluster Services will determine, which of the Nodes NICs is still counting Ethernet-Pakets. The Node whos paket-counter has stopped will get the poison pill.
So, now i´m a little bit confused about the behavior of my 2 Node Cluster!?
1. Is this a normal behavior on OES2 Cluster? (Master always wins)
2. Maybe I´ve got a problem with my NIC-Drivers, so the NCS is unable to determine the Paket-Counter !?!? (VMWare-Tools are installed on both nodes)
3. Is it possible to change this behavior? (Master always wins)
4. I know that a 2 Node Cluster is not the best for high availability and our customer is informed about that!!!! :-)
Thanx for your anwsers!!