Re: Avoid 503 during failover to backup?

From: Alexander Staubo <>
Date: Wed, 3 Dec 2008 19:20:36 +0100

On Wed, Dec 3, 2008 at 4:32 PM, Willy Tarreau <> wrote:
>> Indeed, "emergency redispatch to backups" is one of my
>> yet-unfinished-patches I'm going to clean and publish, eventually.
> I honnestly find this behaviour *very* dangerous and undesirable. Quite
> honnestly, haproxy is most often used with stickyness, and prematurely
> switching to another server is one of the worst things to do. If you
> need to load-balance stateless static servers, why not use LVS instead ?
> Maybe I'm missing some use cases, but it's a general feeling of doing
> the wrong thing.

Willy, I would not be too sure about that. We don't use stickiness, since our backends are interchangable and stateless; and neither do any of the other companies we have talked to that have deployed HAProxy.

Web applications (Rails or Merb or otherwise) tend to be stateless, and HAProxy can be used as a generic L7 load-balancer and a cheap, capable alternative to expensive hardware L7 load-balancers such as BigIP. As others have pointed out, while LVS works, it is at a different level of feature-completeness and complexity that makes it undesirable for many applications.

I sincerely hope that this strange preoccupation with stickiness is not something that will negatively impact HAProxy's future development for us "non-stickies".

Alexander. Received on 2008/12/03 19:20

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