Cluster

[rooble]

Hi experts,

Could you please let me know how data get corrupt in two node cluster if each node try to form individual cluster?

regards,

Rahul

[g3jza]

Hi,
this could happen, if two nodes were trying to access the same data at the same time. That's why is cluster lock mechanism important in a 2-node cluster

[P Arumugavel]

Hi,

If a two-node cluster experiences the loss of all network connections between the nodes. This means that cluster heartbeat ceases. Each node will then try to re-form the cluster separately. This is called split-brain situation. If this were allowed to occur, it would have the potential to run the same application in two different locations and to corrupt application data. In a split-brain scenario, different incarnations of an application could end up simultaneously accessing the same disks. One incarnation might well be initiating recovery activity while the other is modifying the state of the disks. Lock disk requirement is designed to prevent a split-brain situation.

Rgds...

[rooble]

thanks all

[Vivek_Pendse]

If it's a RAC cluster where the vgs/lvs are access in shared mode, then data cannot be corrupted.

In A-P cluster, the vg should be exclusively activated on any of the one node only to void the data corruption. Else, vxfs is very strong & won't be corrupted even though the data base files are opens & have the abrupt shutdowns.

Thanks,
Vivek