DNS Based Load Balancers

Paul Vixie vixie at vix.com
Mon Jul 3 04:09:26 UTC 2006

> The problem being that most of what you linked to below is either A) out
> of date, or B) the only way to get proximity based load balancing (GSLB
> type stuff) with them is with DNS tricks. =20

"most of", huh?  let's have a looksie.

> Breaking it down in order:
>  The IBM solution hasn't been updated since 1999.  It also seems
> relatively proprietary.

the ibm white paper i referred you to was writteh in 1999.  websphere is
quite current, and its implementation of GSLB functionality has been updated
plenty since 1999.  and the competitors james baldwin said he was eval'ing
(cisco, f5) are certainly patent-holders offering proprietary solutions.

>  The Cisco solution relies on either doing HTTP redirects (which is
> useless if you're not doing HTTP) or DNS.  =20

james baldwin said he was using the cisco solution today, so clearly HTTP is
the main target.  i can't think of a protocol requiring GSLB that isn't HTTP
based (either web browsing or web services).  FTP just isn't a growth industry
and the transaction processing systems i know of (the ones that aren't based
on HTTP, that is) have GSLB hooks built into them.

IOW, either you can do GSLB with session redirects, or you don't need GSLB.

>  Both Foundry and Radware rely 100% on DNS to do their GSLB.  You can do
> local load balancing on both boxes   	without, however.

did you read the same radware white paper i did?  in


it says that they can do session level redirects.  so, less than 100% of
radware is dns.  i can see that i misread the foundry whitepaper i ref'd
(perhaps we both saw most readily that data which fit our preconceptions?)

>  The last link is an outdated thesis paper that makes reference moreso
> to local load balancing and not global.

why is it "outdated"?  as a survey of the desired functionality it's still
pretty good background.  no new GSLB has been invented since then, surely?

> It seems that in lieu of a real, currently produced solution, the only
> option is presently DNS to meet the requirements.  Others have sent me
> off-list stuff they're working on, but none of it's ready for prime
> time. =20

well, i see that fezhead is dead.  but 3-party TCP is alive and well:

see also <http://www.tenereillo.com/GSLBPageOfShame.htm>
and      <http://www.tenereillo.com/GSLBPageOfShameII.htm>.

the references sections of those last three are particularly informative.
Paul Vixie

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