Re: duplicate HTTP requests

From: Matt Sanford <matt#twitter.com>
Date: Wed, 5 Nov 2008 10:29:58 -0800


Hi Randall & Anoop,

     This is not something HAProxy can do as far as I know but I can think of two reasons to do this. One is horizontal scaling, but as Randall mentioned choosing which result (or worse, assembling composite results) is not an easy task. I have seen "run-off" systems where you request from multiple back-ends and return the first to complete. That's a pretty seldom used architecture and maintaining state for the multiple un-finished back-ends add overhead.

   The second reason I can think of is for load testing. I've done this sort of "siphon" load testing in the past with apache access logs and some scripting. It does ensure representative load for A/B change testing. As handy as that's been it seems out of scope for HAProxy to me.

   What type of use to you have in mind?

Thanks;

    Matt

On Nov 5, 2008, at 10:21 AM, Randall Svancara wrote:

> For what reason may I ask would you ever want to do this?
>
> Furthermore, how would HAProxy handle the response? Which response
> does
> it return back?
>
> Randall
>
>
> On Wed, 2008-11-05 at 12:54 -0500, Anoop Bhatti wrote:
>> Hello,
>>
>> Is it possible to duplicate a request from one listening server to
>> two
>> other servers?
>>
>> HAProxy is great if you want to configure a request to go to other
>> servers in a round robin fashion. But I'd like to have a
>> configuration that sends the request to both (if they're available),
>> and not do a round robin.
>>
>> Is this possible? If so, how?
>>
>> Thanks,
>>
>> Anoop Bhatti
>> --
>> Committed to open source technology.
>>
>
Received on 2008/11/05 19:29

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