[plt-scheme] Re: Weird timeouts in web-server

From: N N (nothere44 at gmail.com)
Date: Mon Nov 16 16:54:05 EST 2009

I solved my own problem.  Here's what caused it:

web-server/http/request.ss, line 39.  This is in the function read-request.
 When it reads a POST request, it changes the timeout of whatever connection
the request was sent over to be Content Length seconds later.  I'm not sure
when it makes sense to do this, but in my case with a very short request
(Like doit="Go") calling an expensive operation this caused it to timeout.
 I've now copied web-server code to a personal collection where I just
commented this line out.


On Mon, Nov 16, 2009 at 12:32 PM, N N <nothere44 at gmail.com> wrote:

> With initial-connection-timeout set to 300 (5 minutes) I'm still getting
> some deaths due to timeouts, and am at a loss.  I've hunted through
> server code to try to figure out what is going on, but not with much
> success.  Here is what is happening: I navigate to a page with a form.
>  I click on submit for that form and it's intercepted by JavaScript to
> send off to the server in the background a la AJAX and displays the
> results when they return.  Now, I would expect that this background
> submission has the full 5 minutes to complete (and if the time is
> exceeded, it seems from my tests with a 30-second timeout to retry the
> request once with the new connection and full timeout: if you could
> point me to where the logic that does this is I'd be grateful).
> However, in practice it is at times ended much more quickly (54 and 27
> seconds seem the norm) and continues to die to timeouts in the same
> timespan when resubmitted (which seems to me to indicate the time is
> captured in the k-url of the form's action in some way, except that
> the kill-time is stored as an absolute not an offset).
> (It shouldn't matter, but we are using our own LRU continuation
> manager that only differs in that not at maximum memory continuations
> only live for 10 minutes and at maximum 2 minutes.)
> Any insights are appreciated,
> ~NT
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