<p>we're running in this issue. We're using a web service (using soap4r) to run some kind of searches and the problem appears when the webservice server is down and our aplication is trying to connect to it. 
At that point the application is unreachable, and all the customers are blocked.</p>

<p>What can we do to avoid that? Is possibile to block the routing to a mongrel that it is blocked? (I suppose that the apache's proxy uses a round-robin algohritm)</p>

<p>Thanks
Roberto</p>

This sounds to me like it may be more of a mod_proxy problem than one with Mongrel or Apache - are you setting Proxy Timeouts as described
here
?