[dancer-users] Dancer crashing

[Chad Wallace]

On Wed, 13 Mar 2019 10:34:56 -0700
Hermann Calabria <hermann at ivouch.com> wrote:

> Thanks for the reply and comments.
> 
> So we only use Dancer::Standalone for development.  For production,
> we use uwsgi (which btw works phenomenally well as compared to
> Starman).
> 
> This particular version of the software, including with the latest
> version of Dancer 1, is not yet in production, so I don’t yet know if
> we will see this same problem during production.  If the problem only
> surfaces with Dancer::Standalone, I suppose we can live with it….
> what I want to avoid is releasing new software into production that
> has this problem from day 1.  I understand uwsgi will simply restart
> the crashed process, but that’s no way to run at scale, and also the
> user will experience an error and may not know to just “refresh”.

Have you been able to reproduce it?  The errors you posted indicate
the other end of the connection is no longer there.  That's probably
caused by the user closing the connection (e.g., closing their
browser or turning off the computer).  If they're not there anymore, you
don't need to worry about sending them a response.

> From: Stefan Hornburg (Racke)
> Sent: Wednesday, March 13, 2019 10:00 AM
> To: dancer-users at dancer.pm
> Subject: Re: [dancer-users] Dancer crashing
> 
> On 3/13/19 4:51 PM, Hermann Calabria wrote:
> > I don’t have fatal warnings turned on.
> > 
> >  
> > 
> > Also, reviewing the stack trace, none of the calls appear to go
> > through the app.  The only packages involved are:
> > 
> >  
> > 
> > HTTP::Server::Simple
> > 
> > Dancer::Handler::Standalone
> > 
> > Dancer::Handler
> > 
> > Dancer
> > 
> >    
> 
> Hello Herrmann,
> 
> at any rate my advise would be to not use dancer standalone at all,
> especially not in a production environment.
> 
> With plackup + starman you get a more reliable environment, and you
> can restrict the lifetime of the workers by using plackup's
> --max-requests option.
> 
> That is useful to limit memory growth and other hard to track
> problems occurring on long running applications.
> 
> Regards
>          Racke
> 
> > 
> >  
> > 
> > *From: *Andrew Beverley <mailto:andy at andybev.com>
> > *Sent: *Tuesday, March 12, 2019 3:56 PM
> > *To: *Perl Dancer users mailing list <mailto:dancer-users at dancer.pm>
> > *Cc: *Hermann Calabria <mailto:hermann at ivouch.com>
> > *Subject: *Re: [dancer-users] Dancer crashing
> > 
> >  
> > 
> > On Tue, 12 Mar 2019 15:08:46 -0700 Hermann Calabria wrote:
> >   
> >> Sure, it’s probably something my app is doing.  However I expect  
> >   
> >> Dancer to be resilient enough to not crash in this manner.  
> > 
> >  
> > 
> > FWIW, I did notice that the crash appeared to happen because of an
> > 
> > uninitialized value. Do you have fatal warnings turned on, and could
> > 
> > that be one of the causes? I don't know, but does Dancer normally
> > run
> > 
> > without fatal warnings, and maybe the problem you encountered
> > wouldn't
> > 
> > normally be fatal?
> > 
> >  
> > 
> > Andy
> > 
> >  
> > 
> > 
> > _______________________________________________
> > dancer-users mailing list
> > dancer-users at dancer.pm
> > http://lists.preshweb.co.uk/mailman/listinfo/dancer-users
> >   
> 
> 


-- 

C. Chad Wallace, B.Sc.
The Lodging Company
http://www.lodgingcompany.com/
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