Hash director and backend health

[Ken Brownfield]

You could have the hash backends each be individual round/random directors
with your intended server having a very high weight and your intended backup
backend a weight of 1.  Awkward and somewhat lengthy, but it works.  The
only downside is that the fallback will get a non-zero amount of traffic.

director example hash {
       .retries = 5;
       { .backend = server1d; .weight = 1; }
(...)
       { .backend = server8d; .weight = 1; }
}

director server1d random {
       { .backend = server1;   .weight = 10000000; }
       { .backend = fallback1; .weight = 1; }
}

Yes, I believe the hash director is strict and ignores health, at least when
I played with it (very) briefly.

At some point in Varnish's future, it would probably be worth implementing a
backup backend at the director or even backend level.  Or at least a
fallback director/backend for hash, but the former is a more general
solution.
-- 
kb

On Mon, Aug 1, 2011 at 00:35, Thiago Figueiro <TFigueiro at au.westfield.com>wrote:

> KT Sin wrote:
> > try adding backend probes. see:
> > https://www.varnish-cache.org/trac/wiki/BackendPolling
>
> Yep, they're there.
>
> Thanks tho.
>
>
> ______________________________________________________
>    CONFIDENTIALITY NOTICE
> This electronic mail message, including any and/or all attachments, is for
> the sole use of the intended recipient(s), and may contain confidential
> and/or privileged information, pertaining to business conducted under the
> direction and supervision of the sending organization. All electronic mail
> messages, which may have been established as expressed views and/or opinions
> (stated either within the electronic mail message or any of its
> attachments), are left to the sole responsibility of that of the sender, and
> are not necessarily attributed to the sending organization. Unauthorized
> interception, review, use, disclosure or distribution of any such
> information contained within this electronic mail message and/or its
> attachment(s), is (are) strictly prohibited. If you are not the intended
> recipient, please contact the sender by replying to this electronic mail
> message, along with the destruction all copies of the original electronic
> mail message (along with any attachments).
> ______________________________________________________
>
> _______________________________________________
> varnish-misc mailing list
> varnish-misc at varnish-cache.org
> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.varnish-cache.org/lists/pipermail/varnish-misc/attachments/20110801/e10ace57/attachment-0003.html>