[racket-dev] Suggestions for monitoring unresponsive web server connection?

From: Kathi Fisler (kfisler at gmail.com)
Date: Wed Sep 7 06:38:33 EDT 2011

Following up on this -- what's the max number of open file descriptors that
Racket allows? We're seeing some lingering ones (trying to trace the source,
but wondering if this is the problem).

We are also getting a lot of ssl error reports of the forms

Connection error: ssl-accept/enable-break: accept failed (error:1407609C:SSL
routines:SSL23_GET_CLIENT_HELLO:http request)

Connection error: ssl-accept/enable-break: accept failed (input terminated
prematurely)
 === context ===
/home/turnin/plt-5.1.1/lib/racket/collects/openssl/mzssl.rkt:919:10: loop
/home/turnin/plt-5.1.1/lib/racket/collects/mzlib/thread.rkt:69:12: loop

We're not doing any manual SSL operations (just the ssl settings to the web
server startup).  Still, are these traceable to something in our code?

thanks,
Kathi

On Tue, Sep 6, 2011 at 8:13 PM, Kathi Fisler <kfisler at gmail.com> wrote:
> Our homework submission application, currently running under 5.1.1
> with Jay's stateless infrastructure, has been going unresponsive on us
> a lot lately.  In some cases, the process is still alive but the web
> server does not respond to requests.  In some cases, the process has
> died.   While this sometimes happens concurrently with high load, load
> is neither necessary nor sufficient.
>
> Are there commands we can use when we startup racket or the server
> that might give diagnostics to help trace the problem?
>
> We are not getting core dumps (even when the process dies).  So far,
> monitoring top output hasn't revealed anything unusual or telling.
>
> Here's the uname -a listing, in case that is helpful:
>
> Linux turnin.cs.wpi.edu 2.6.18-238.12.1.el5 #1 SMP Tue May 31 13:22:04
> EDT 2011 x86_64 x86_64 x86_64 GNU/Linux
>
> thanks,
> Kathi
>
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