[openstack-dev] [nova] [all] FYI: Removing default flavors from nova

Neil Jerram Neil.Jerram at metaswitch.com
Wed Apr 6 17:15:33 UTC 2016

I hesitate to write this, even now, but I do think that OpenStack has a 
problem with casual incompatibilities, such as this appears to be.  But, 
frankly, I've been slapped down for expressing my opinion in the past 
(on the pointless 'tenant' to 'project' change), so I just quietly 
despaired when I saw that ops thread, rather than saying anything.

I haven't researched this particular case in detail, so I could be 
misunderstanding its implications.  But in general my impression, from 
the conversations that occur when these topics are raised, is that many 
prominent OpenStack developers do not care enough about 
release-to-release compatibility.  The rule for incompatible changes 
should be "Just Don't", and I believe that if everyone internalized 
that, they could easily find alternative approaches without breaking 

When an incompatible change like this is made, imagine the 1000s of 
operators and users around the world, with complex automation around 
OpenStack, who see their deployment or testing failing, spend a couple 
of hours debugging, and eventually discover 'oh, they removed m1.small' 
or 'oh, they changed the glance command line'.  Given that hassle and 
bad feeling, is the benefit that developers get from the incompatibility 
still worth it?

I would guess there are many others like me, who generally don't say 
anything because they've already observed that the prevailing sentiment 
is not sufficiently on the side of compatibility.


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