Re: [DNSOP] BCP on rrset ordering for round-robin? Also head's up on bind 9.12 bug (sorting rrsets by default)

Paul Vixie <paul@redbarn.org> Mon, 18 June 2018 17:46 UTC

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Date: Mon, 18 Jun 2018 18:45:27 +0100
From: Paul Vixie <paul@redbarn.org>
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Subject: Re: [DNSOP] BCP on rrset ordering for round-robin? Also head's up on bind 9.12 bug (sorting rrsets by default)
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to the extent that the dns technical community has a choice about 
default behaviour, we should consider the costs to the rest of the 
internet community of each default.

in my prior e-mail to this thread i gave examples of assumptions of 
ordering that were violated by the first round-robin implementation. in 
both cases, the assumption was dangerous -- led to fragility. (leaving a 
bad NS in an RRset, and putting verses of poetry in TXT RRsets.)

assumptions of non-ordering are less dangerous. (expect load balancing 
and don't get it.)

we should, if we can engage on the topic of defaults at all, recommend a 
default that is compatible with less-dangerous assumptions.

in other words we should re-order rrsets by default, so that very few 
people or agents are ever prone to think their order is stable. the spec 
says they are unordered, but human nature says, expect more of what 
you're seeing.

vixie