[Web-SIG] Web Container Interface

[Ian Bicking]

Phillip J. Eby wrote:
> At 03:14 PM 1/30/04 -0600, Ian Bicking wrote:
> 
>> Sessions remain the use case I consider to be unresolved.  I think 
>> sessions should be possible to implement portable, without requiring 
>> configuration that specifies the gateway's process/concurrency model. 
>> (That doesn't rule out configuration, just that in the absence we 
>> should be able to pick the right implementation)
>>
>> Probably all this requires is a way to indicate the process model.
> 
> 
> How about by indicating whether the application can be
> 
> 1. Run in multiple processes
> 2. Run by multiple threads
> 
> as information exposed by the app?  Or do you think that we should have 
> a "setup" method called by the container to tell the app what model it's 
> going to be run under?

Yes, I think we need a setup call.  I want the app to be able to respond 
to the environment, not merely indicate compatibility.  Compatibility 
can then be asserted by throwing an exception if you use the application 
in an inappropriate container.

Maybe it's even sufficient to pass this information in an environmental 
variable, though that would imply that the information may only apply to 
a single request.  But I don't know how you could change the situation 
between requests, except to spawn threads in a LRSP-single environment.

Either way we have to specify clearly what the models are.

>> Yes, my point was just that Twisted .rpy scripts and the like wouldn't 
>> fit into the model.  Or, they could, but it would be kind of silly, 
>> since you'd loose all the advantages of async, even if you ran under a 
>> Twisted gateway.  In contrast, many other systems could be composed 
>> into gateway and application without any real downside.
> 
> 
> Right.  The goal for WSGI in the case of Twisted is to let people 
> migrate apps *to* Twisted, not *from* it.  :)  I don't think that 
> migrating from Twisted to anything other than another event-driven 
> framework (e.g. peak.events) is even possible, and there aren't any 
> mature alternatives with comparable capabilities to Twisted at the 
> moment, if i understand correctly.

In the scope of web applications Medusa is very similar, isn't it? 
Fairly significant applications are written with Medusa and without any 
threads (PyDS, for instance).  But that's an aside.

   Ian