Backend polling not working

Izak Burger izak at
Thu Oct 15 09:46:54 CEST 2009

Izak Burger wrote:
> I then added some extra log statements to the C code and confirmed that 
> the do/while loop that is supposed to read the response terminates on 
> the very first read() call with an EOF.
> In other words, there is definitely something wrong with varnish here.
> I suspect the problem might be with poll(), although I have yet to 
> confirm that. Specifically, it seems that the case where poll() returns 
> -1 is not handled properly. At the least I think it should handle EINTR? 
> I'll check that later and let you know.

Alright, I have to take that back. I changed the port so varnish talks 
to apache instead and that works. That means zope somehow manages to 
cause a POLLIN event on the file descriptor even though there is nothing 
to read. Will have to do more research on this.

 From various sources found by google, it seems backend probing fails in 
a similar manner with nginx.


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