Web Services Come of Age


For years I've reacted to the hype surrounding web services with skepticism. I found SOAP, WSDL, and UDDI to be too complex and brittle for wide deployment, and I also wondered what types of services could be better provided over the web rather than locally. A new excellent developer site, Stack Overflow, answers both of my concerns.

Stack Overflow uses web services for three aspects of its operation:

  1. reCAPTCHA to avoid spam robots,
  2. OpenID for user identification, and
  3. gravatar to obtain user avatars.
All three services rely on the web for their operation. reCAPTCHA is a centralized service that scans books by distributing the work among millions of human readers. OpenID and gravatar solve the problem of setting up and maintaining a separate identity for each site, while also providing a more functional and secure alternative than the typical home brew implementation. So there is clearly a space for valuable web services; I was wrong to doubt that.

On the technical side all three services are not based on SOAP protocols; they all use simple REST-style HTTP requests. For instance, obtaining a gravatar JPEG file is a simple matter of appending the email's MD5 to the URL http://www.gravatar.com/avatar/. So on the technical side of the web services argument I feel vindicated: the winner is simplicity.

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Last modified: Wednesday, September 24, 2008 10:47 am

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Unless otherwise expressly stated, all original material on this page created by Diomidis Spinellis is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.