Need help setting up cache for failover

[B.R.]

I notice error_page is used at server level while fastcgi_cache_use_stale
is at http level. error_page has thus higher precedence than the last. I
would give a shot at putting both at the same level and see what happens.

I trust error_page is some kind of 'last resort' feature, handling an error
which is considered as such. Since fastcgi_cache_use_stale might triggers
on errors coming from the backend, I would say it should filter them before
they are considered by nginx as an error (and thus being processed as such,
as the *_intercept_errors directive do).

So the only reason I see error_page being triggered before
fastcgi_cache_use_stale would be the higher precedence of the server
environment over the http one. Test, test, test. :o)
---
*B. R.*

On Thu, Dec 4, 2014 at 6:09 PM, Fry-kun <nginx-forum at nginx.us> wrote:

> I am; that was a copy/paste error. The original config is around 3000
> lines,
> it was easier to type & copy/paste than cleaning up unnecessary lines.
>
>
> ~Konstantin
>
>
> B.R. Wrote:
> -------------------------------------------------------
> > Quick quesiton; I see you are using proxy_intercept_errors. Should not
> > you
> > be using fastcgi_intercept_errors
> > <http://nginx.org/en/docs/http/ngx_http_fastcgi_module.html#fastcgi_in
> > tercept_errors>
> > ?
> > ---
> > *B. R.*
> >
> > On Thu, Dec 4, 2014 at 2:25 AM, Fry-kun <nginx-forum at nginx.us> wrote:
> >
> > > I'm trying to configure my sites to failover to fastcgi_cache when
> > backends
> > > are unavailable -- but at the same time I want to return nginx
> > errors
> > > (hiding backend errors)
> > >
> > > Here's a simplified version of my current config:
> > >
> > > fastcgi_cache_path  /dev/shm/nginx_fastcgi_cache  levels=1:2
> > inactive=3d
> > > keys_zone=mycache:100m max_size=5000m;
> > > fastcgi_cache_use_stale  error http_500 http_503 timeout updating;
> > > fastcgi_cache_valid      200  5m;
> > > fastcgi_cache_valid      404  1m;
> > > proxy_intercept_errors on;
> > > server  {
> > >   server_name  domain.com
> > >   root  /var/www/domain.com;
> > >   location  /  {
> > >     try_files  $uri  @hhvm_backends;
> > >   }
> > >   location  @hhvm_backends  {
> > >     fastcgi_pass  backend-nodes;    # upstream hhvm backends
> > >     fastcgi_cache  mycache;
> > >     ...
> > >   }
> > >   error_page  404  @404;
> > >   error_page  500  @500;
> > >   location  @404  {  echo "404: file not found!";  }
> > >   location  @500  {  return  500;  }    # default nginx error page
> > > }
> > >
> > >
> > > Right now, if the server is down and location is stale in cache, I
> > get the
> > > default nginx 500 error page.
> > > According to debug log, the problem with this one is that error_page
> > > handling takes over before fastcgi_cache_use_stale has a chance to
> > do its
> > > thing.
> > >
> > > Is there an easy way to fix this?
> > >
> > > Thanks
> > >
> > > Posted at Nginx Forum:
> > > http://forum.nginx.org/read.php?2,255298,255298#msg-255298
> > >
> > > _______________________________________________
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> > >
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>
> Posted at Nginx Forum:
> http://forum.nginx.org/read.php?2,255298,255307#msg-255307
>
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