Hash director and backend health

[KT Sin]

hi

try adding backend probes. see:

https://www.varnish-cache.org/trac/wiki/BackendPolling

kt

On Mon, Aug 01, 2011 at 06:34:37AM +0000, Thiago Figueiro wrote:
> KT Sin wrote:
> > the hash director will fail if all the backends are failing. if you
> > define a random director with the same set of backends, and if the hash
> > director fails, the random director fails too?
> 
> That's not what I'm seeing in my tests.
> 
> I have 8 servers in the hash director and I only took 1 of them offline, the one a test URL resolves to.  If I request a different URL I get a response; if I request the URL that goes to the offline server I get 503.
> 
> Here are some successful log entries:
>    53 RxURL        c http://www.westfield.com.au/au/?thiago-1
>    53 Backend      c 42 centre_rails centre_rail_ausyd_fap05
>    46 RxURL        c http://www.westfield.com.au/au/?thiago-2
>    46 Backend      c 41 centre_rails centre_rail_ausyd_fap04
> 
> If I take fap05 offline and try both URLs again I see an error:
>    46 RxURL        c http://www.westfield.com.au/au/?thiago-1
>    46 FetchError   c no backend connection
>    46 TxStatus     c 503
>    42 RxURL        c http://www.westfield.com.au/au/?thiago-2
>    42 Backend      c 41 centre_rails centre_rail_ausyd_fap04
> 
> So "thiago-1" goes to fap05 and "thiago-2" goes to fap04.  If I stop fap05, I get "FetchError" for "thiago-1", however "thiago-2" responds normally.
> 
> 
> 
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