Locks are not sufficient, because there is no way to enforce a lock in a
distributed system without unbounded blocking. What you might be referring
to is a lease, but leases are still problematic unless you can put bounds
on the speed with which clocks progress on different machines, _and_ have
strict guarantees on the way each node's scheduler works. With Linux and
Java, the latter is tough.
You may want to look into QuorumJournalManager which doesn't require
setting up IO fencing.
On Thu, Oct 25, 2012 at 1:27 AM, lei liu <[EMAIL PROTECTED]> wrote:
> I want to use HDFS HA function, I find the IO Fencing function is
> complex in hadoop2.0. I think we can use file lock to implement the IO
> Fencing function, I think that is simple.
Software Engineer, Cloudera