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From Riyad Kalla <rka...@gmail.com>
Subject Re: High latency (40ms) and low request rate (10 rps) under windows
Date Wed, 26 Oct 2011 23:52:14 GMT
Hmm, I see what you mean. If a single connection isnt pegging any of the hardware and multiple
connections are a magnitude times faster, I am not sure what would be keeping the single connection
from performning faster.

Maybe someone else can hop in with ideas? 

R

On Oct 26, 2011, at 4:32 PM, Konstantin Cherkasoff <k.cherkasoff@gmail.com> wrote:

> Hi!
> 
>> What happens when you set delayed_commits to true?
> With delayed_commits I got about 150 rps so delayed_commits mode is 15
> times faster.
> 
>> With that off you are requiring an fsync (iirc)  after every value written and then
are at the
>> mercy at your disks write performance (but not in the sense of burst-write
>> as these are individual, disparate write requests coming in).
> 
> Yes, I understand that many small writes and fsyncs can be a
> bottleneck in this case.
> But I found that the increase of number of concurrent requests lead to
> an increase in the request rate.
> For example (100 concurent requests)
>> ab -k -t 10 -c 100 -n 1000000 -p ab.json -T "application/json" http://localhost:5984/bench
> shows about 300 RPS (writes and fsyncs) on the same hardware.
> 
> So, I suppose that 10 requests per second actually is not the limit
> for this hard disk.
> And there may be some other problem.
> 
>> Also, is this build Couch Single Server from Couchbase or some other Windows build
of Couch?
> I tried Couchbase 1.2.0 and
> this build https://github.com/downloads/dch/couchdb/setup-couchdb-1.1.0+COUCHDB-1152_otp_R14B03.exe
> 
> 
> --
> Konstantin

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