Re: [Gluster-devel] Can I bring a development idea to Dev's attention?

[Ed W]

 Does someone from Gluster like to contact me with a "reasonable" offer 
for sponsoring some kind of "optimistic cache" feature, with a specific 
view to optimising the NUFA server side replication architecture?

I would specifically like to optimise the case that you have a flat 
namespace on the server (master/master filesharing), but you optimise 
the applications in such a way that the applications running on each 
brick (NUFA) only touch a subset of all files (in general).  eg a 
mailserver with a flat filesystem, but users are proxied so that they 
generally touch only a specific server, or a webserver with a flat 
namespace where a proxy points specific domains to be served by specific 
servers?

In this case I would like to see a specific brick realise that it's 
predominantly the reader/write for a subset of all files and optimise 
it's access at the expense of other bricks which need to access the same 
files (ie I don't just want to turn up the writeback cache, I want cache 
coherency across the entire cluster).  I would accept that random 
read/writes to random bricks would be slower, in return for the 
optimisation that reads/writes would be faster *if* the clients optimise 
themselves to *prefer* to touch specific bricks (ie NUFA).  Such an 
optimisation should not be set in stone of course, if the activity on a 
subdirectory generally seems to move across to another brick then that 
brick should eventually optimise it's read/write performance (at the 
expense that another brick's access now becomes slower to that same 
subset of files.)

Anyone care to quote on this?  Seems like it's a popular performance 
issue on the mailing list and with some optimisation later it also seems 
like the basis for cross datacenter replication?


Thanks

Ed W