All the Perl that's Practical to Extract and Report

Top two guidelines to using SOAP

ziggy on 2002-08-27T17:37:47

From Phil Windley's blog:

  • Message-based SOAP: good
  • RPC-style SOAP: bad
Phil is the CIO of the state of Utah. He's got oodles of street cred, and he's much more than the beneficiary of a patronage appointment. We need more clued-in people like him in government.

SOAP-RPC is easy, and a quick win for techies. But it doesn't address enterprise-scale deployment issues, which is why SOAP-RPC has scalability problems. (And why SOAP needs all of the extra layers of complexity to be truly useful.)

Not enough detail

jjohn on 2002-08-27T20:47:52

X good! Y Bad! Fire BAD!

That blog didn't have enough context to understand why SOAP-RPC is bad. I gather that SOAP-RPC is a poor replacement for insert-favorite-rpc-tech-here because SOAP (and XML-RPC) don't support concurrent distributed applications (i.e. there's no support for an transaction logic or security).

Tell me somthing I don't know.

Anyone who suggests that XML over HTTP is a drop-in replacement for CORBA is smoking crack. This smells like a strawman argument to me. SOAP-RPC is fine, given an understanding of its limitations.

Re:Not enough detail

ziggy on 2002-08-27T21:46:04

Anyone who suggests that XML over HTTP is a drop-in replacement for CORBA is smoking crack.
Then there are be oodles of tech people smoking crack. But you already knew that. :-)

Yes, Windley's trite soundbite is an oversimplification. But when everything surrounding SOAP is overabstracted, overhyped, and exceedingly verbose, I think a simple two line explanation is a good thing.

The original idea behind XML-based RPC was to send complete messages between parties. Somehow, XML-RPC came out first and locked all up all the mindshare. In fact, for the first year or two that SOAP was around, my gut feeling was that SOAP was simply XML-RPC made more verbose, with a footnote about mumble-mumble-document-mumble-something.

Re:Not enough detail

ziggy on 2002-08-27T21:57:02

D'OH! Hit that submit button instead of the preview button....

I buy Windley's point that RPC is an old technology that's fundementally unscalable. Wrap it up in new fangled clothes, and it's still fundementally unscalable. To the audience who is buying into anything with a SOAP label, this is dangerous, since the differences aren't addressed very well (what does "SOAP Compliant" mean anyway?).

Explaining the differences between SOAP-RPC and SOAP-Messaging is important, and Windley's comment is the best summarization of 80% of that discussion. Perhaps a three line comment would summarize another 15% of the issues. :-)