[Gluster-devel] regarding GF_CONTENT_KEY and dht2 - perf with small files

[Ira Cooper]

Pranith Kumar Karampuri <pkarampu at redhat.com> writes:

> On 02/03/2016 07:54 PM, Jeff Darcy wrote:
>>> Problem is with workloads which know the files that need to be read
>>> without readdir, like hyperlinks (webserver), swift objects etc. These
>>> are two I know of which will have this problem, which can't be improved
>>> because we don't have metadata, data co-located. I have been trying to
>>> think of a solution for past few days. Nothing good is coming up :-/
>> In those cases, caching (at the MDS) would certainly help a lot.  Some
>> variation of the compounding infrastructure under development for Samba
>> etc. might also apply, since this really is a compound operation.
> Even with compound fops It will still require two sequential network 
> operations from dht2. One to MDC and one to DC So I don't think it helps.

You can do better.

You control the MDC.

The MDC goes ahead and forwards the request, under the client's GUID.

That'll cut 1/2 a RTT.

Cheers,

-Ira