[Linux-ha-dev] Shared disk file Exclusiveness controlprogramforHB2
ikedaj at intellilink.co.jp
Tue Aug 14 00:41:05 MDT 2007
> OK. I think you are mis-understanding the problem.
> When the communication between Node A & B is fine, you don't need any
> kind of lock. Heartbeat itself can ensure the resource runs on one
> node, and on one node only.
sfex_lock() is just checking the status that shows which node succeeded to
It won't be always trying to lock over and over again
> sfex_lock is valuable when the communication between A & B is broken.
> But when the communication IS broken, you can't assume sfex_lock will run
> in order any more.
If the interconnect LAN is down, Split-Brain will come.
the lock status is reserved for Node A at this moment,
but Node B is also trying to update the status in order to lock because
Split-Brain has arisen.
while Node A checks the status, Node B might update it.
Node A, which is overwrote its status, is going to release the lock.
sfex_lock() doesn't have such a complex logic.
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