[Gluster-devel] Improving real world performance by moving files closer to their target workloads

[gordan at bobich.net]

On Fri, 16 May 2008, Derek Price wrote:

> gordan at bobich.net wrote:
>> This would need a change in the handling of how a file is locked/accessed. 
>> A lock would need to be made on all the nodes that could respond with the 
>> file. AFR doesn't quite do this, the primary node (first one on the AFR 
>> list) is the one that acts as the lock server. If this could be overcome, 
>> then you'd have most of the components you need.
>
> What about a quorum locking solution like DLM provides?  I think it doesn't 
> matter if the server(s) that have copies of the files agree to the file lock, 
> as long as any server that wants a lock knows to get approval from the 
> quorum.

Isn't that effectively the same thing? Unless there is quorum, DLM locks 
out the entire FS (it also does this when a node dies, until it gets 
definitive confirmation that it has been successfully fenced). For normal 
file I/O all nodes in the cluster have to acknowledge a lock before it can 
be granted.

Gordan