Thilina Buddhika wrote:
> hi,
> i want to write a web service using Ruby. This is not the client, but
> the service.

Well, you'll have to define "service".

> Is there any good reference for writing services in Ruby. what i found
> in the web were about writing clients using Ruby. But i want articles
> about writing services.
> 


For REST services (which is likely the path you will want to take), the 
  book RESTful Web Services, by Leonard Richardson, is pretty good.  It 
seems to have a an unusually large number of small but annoying errors, 
but the fundamental ideas are quite sound and there is a good deal of 
Ruby code in there.


-- 
James Britt

"Programs must be written for people to read, and only incidentally
  for machines to execute."
   - H. Abelson and G. Sussman
   (in "The Structure and Interpretation of Computer Programs)