768695 - Recursive WSGI requests time out

Status: RESOLVED WONTFIX

(Petri Graveyard :: General, defect)

Description

[Ian Bicking (:ianbicking)]

If you make a request, using urllib.urlopen, from your web server back to the same server, it appears to time out.  

I'm guessing this is something about a single-threaded execution model, though even then I thought there were patches applied to handle this case with sockets.

Comment 1

[Philippe M. Chiasson (:gozer)]

(In reply to Ian Bicking (:ianb) from comment #0)
> If you make a request, using urllib.urlopen, from your web server back to
> the same server, it appears to time out.  
> 
> I'm guessing this is something about a single-threaded execution model,
> though even then I thought there were patches applied to handle this case
> with sockets.

Can't say for sure, I guess it depends on the execution framework you use in the back-end, but, yes if your WSGI app is single-threaded, you have an issue.

Have you tried increasing the number of instances of your app with something like:

$> vmc instances appname 4

And trying again ?

CloudFoundry lets you scale out your app by running multiple instances of it. But even then, it sounds like your app/framework needs some fixing to be able to handle more than just a few concurrent connections...

Comment 2

[Ian Bicking (:ianbicking)]

A WSGI app doesn't itself include any specific concurrency model, that's the responsibility of the container (gunicorn, as configured by CloudFoundry).  I wonder if it's a gunicorn configuration problem?  gunicorn is also used by Services in their deployments.  Tarek: do you know any configuration parameter that would make recursive HTTP requests work or not with an app under gunicorn?

When I try "vmc instances seeitsaveit 4" I get a Not Authorized error.

Comment 3

[Philippe M. Chiasson (:gozer)]

I'll check the generated gunicorn config.

For the vmc instances, your login ticket probably expired, have you tried logging back into vmc first?

$> vmc login

Comment 4

[Ian Bicking (:ianbicking)]

vmc login worked, and increasing the instances to 4 did fix the recursive request problem.

Comment 5

[Tarek Ziadé (:tarek)]

No I don't think there's anything like this in gunicorn.