[Lustre-devel] Queries regarding LDLM_ENQUEUE

[bzzz.tomas at gmail.com]

On 10/20/10 8:43 PM, Paul Nowoczynski wrote:
> It's for scalability reasons. When N clients traverse the namespace with
> the purpose of opening the same file the result is a storm of RPC
> requests which bear down on the metadata server. This type of activity
> becomes prohibitive especially when you start considering client counts
>  > 10^4. An operation such as this is ripe for optimization because
> every client in the network is trying to build the same state. If you
> have a method for a single client to 'learn' the final state, i.e. the
> pathname -> fid translation, and broadcast it to its cohorts, it's a
> huge win because it eliminates an O(N) operation.
> paul

clear enough, but what is the bottleneck here: MDS to handle lots of
RPCs or network to pass RPCs ?

thanks, z