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From Tom Evans <tevans...@googlemail.com>
Subject Re: [users@httpd] Load Balancing question
Date Thu, 04 Aug 2011 14:57:46 GMT
On Thu, Aug 4, 2011 at 3:43 PM, Jim Jagielski <jim@jagunet.com> wrote:
> You will note that the balancer in 2.3/2.4 resolves this issue.
>
> BTW, the idea that mod_proxy_balancer is "broken" only means that
> it does not do what you expect, which is restore all local mods
> made via balancer_manager, but this was never guaranteed.
>
>

No, it applies state randomly and indiscriminately. The first time
this happened to us, one balancer cluster ended up with all backends
enabled, when only one was before the graceful restart, and yet
another had all backends disabled, when one should have been.

IE, it left the balancer members in a state where it was neither the
configuration on disk, nor the configuration before restart. That is
what I call broken - an entirely unpredictable state.

Given that load balancers are typically used to increase availability
and reliability of a web service, a load balancer which consistently
screws up the state is about as useful as an umbrella with holes in
it.

Cheers

Tom

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