[erlang-questions] couchdb performace 10x: using NIF for file io

Edmond Begumisa <>
Wed Oct 27 09:46:01 CEST 2010


Hi,

I hope the Couch team isn't planning on doing this by default -- something  
about it makes me nervous...

When CouchDB is on it's own, it might not be alarming/noticeable, but I'm  
using CouchDB "embedded" in a wider Erlang/OTP application stack (i.e.  
where Couch is just one of many OTP apps running in the *SAME* VM -- I  
have a few hacks for avoiding socket communication.) I too worry about the  
potential for NIF-endowed couch io disturbing the balance of Erlang's  
scheduling.

It would be good to see similar benchmarking with the VM concurrently  
doing things other than handling couch-related requests (which are  
implicitly synchronised in your case.)

- Edmond -

On Mon, 25 Oct 2010 07:59:11 +1100, Joel Reymont <> wrote:

>
> On Oct 24, 2010, at 7:16 PM, Kenneth Lundin wrote:
>
>> I wonder how responsive the system is to other events when running the
>> benchmark.
>
> The benchmark simulates several hundred clients hitting a (mochiweb) web  
> server to read and write couchdb (json) documents. The system seems to  
> stay -highly- responsive, 10x so compared to the same system not using  
> NIFs at all.
>
> If low write response time is taken as a measure of system  
> responsiveness then the first graph shows that the responsiveness of the  
> system has increased dramatically. The write response here is the take  
> taken to process a web request to write a couch document.
>
> ---
> http://twitter.com/wagerlabs
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:
>


-- 
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/


More information about the erlang-questions mailing list