Re: [monit-dev] Add a hostheader option to monit's http check.

[Brady Catherman]

On Sep 30, 2009, at 7:02 PM, Jan-Henrik Haukeland wrote:

> On 1. okt. 2009, at 02.58, Brady wrote:
>
> >   if failed host localhost port 6000 protocol http and request '/ 
> > testing' hostheader 'example.com' with timeout 20 seconds for 2  
> > cycles then restart
>
>
> Just to clarify, this statement which you can write in Monit already  
> produce the same request as in your patch:
>
>   if failed host example.com port 6000 protocol http and request '/ 
> testing' then restart


That works if you have a fairly simple server setup, but if you have  
10 hosts sitting behind a CNAME then your suggested approach will not  
do the right thing. It will connect to one of the 10 hosts, and if it  
works then it will allow the local host to survive. Even worse, if  
your service sites behind a globally load balanced pool then draining   
traffic away from a location will disable all local protocol checking.

In our case we have several layers of front ends between the  
resolvable host name, and the software we are monitoring. We monitor  
the port/IP pair and try to wrap configuration such that monit's  
requests make it through, but this patch allows us to just fetch the  
host name we expect without any special cases in our software configs.

- Brady