10 messages in ru.sysoev.nginxRe: Does any module support the heath...
FromSent OnAttachments
ChieuMay 31, 2009 3:55 am 
mingjiang huangJun 8, 2009 2:25 am 
Michael ShadleJun 8, 2009 1:11 pm 
Avleen VigJun 9, 2009 4:01 am 
Michael ShadleJun 9, 2009 10:13 am 
merlin coreyJun 10, 2009 2:20 pm 
Michael ShadleJun 10, 2009 2:27 pm 
merlin coreyJun 10, 2009 2:44 pm 
Michael ShadleJun 10, 2009 2:58 pm 
ChieuJun 10, 2009 8:40 pm 
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Subject:Re: Does any module support the heathy check of the backend upstreams?Actions...
From:Michael Shadle (mike@gmail.com)
Date:Jun 10, 2009 2:58:12 pm
List:ru.sysoev.nginx

On Wed, Jun 10, 2009 at 2:45 PM, merlin corey<merl@dc949.org> wrote:

How often do you really expect servers to go up and down?  I think you are correct, though, HUP can take a bit of time/resources.  My point is, are you really having upstreams die constantly?  Seems like you would have much worse problems than what it takes to HUP at that point...

In an infrastructure with 10's or 100's of servers, in theory you could have one going up and down anytime.

Look at Amazon's whitepaper about Dynamo or how Google addresses the whole "commodity" issue. Things will go up and down at anytime, and you should gracefully handle it. nginx is almost capable of gracefully doing it (mid-transfer I don't think it would unless the client re-issued the request with a range offset) but with the try-next-upstream approach it gracefully handles that already...

I'm looking to have a solution in place which can scale and is "set it and forget it" - a HUP may be a lot of work, especially if nginx is being the frontend for so many connections/servers. I don't know. I guess Igor/Maxim would be the most knowledgeable about what exactly a HUP will do to all of that...