Open Stack

On 12/04/2018 08:15 AM, Thierry Carrez wrote:
> Julia Kreger wrote:
>> Indeed it is a considered a base service, but I'm unaware of why it 
>> was decided to not have any abstraction layer on top. That sort of 
>> defeats the adoption of tooz as a standard in the community. Plus with 
>> the rest of our code bases, we have a number of similar or identical 
>> patterns and it would be ideal to have a single library providing the 
>> overall interface for the purposes of consistency. Could you provide 
>> some more background on that decision?
> 
> Dims can probably summarize it better than I can do.
> 
> When we were discussing adding a DLM as a base service, we had a lot of 
> discussion at several events and on several threads weighing that option 
> (a "tooz-compatible DLM" vs. "etcd"). IIRC the final decision had to do 
> with leveraging specific etcd features vs. using the smallest common 
> denominator, while we expect everyone to be deploying etcd.
> 
>> I guess what I'd really like to see is an oslo.db interface into etcd3.
> 
> Not sure that is what you're looking for, but the concept of an oslo.db 
> interface to a key-value store was explored by a research team and the 
> FEMDC WG (Fog/Edge/Massively-distributed Clouds), in the context of 
> distributing Nova data around. Their ROME oslo.db driver PoC was using 
> Redis, but I think it could be adapted to use etcd quite easily.

Note that it's not appropriate to replace *all* use of an RDBMS in 
OpenStack-land with etcd. I hope I wasn't misunderstood in my statement 
earlier.

Just *some* use cases are better served by a key/value store, and 
etcd3's transactions and watches are a great tool for solving *some* use 
cases -- but definitely not all :)

Anyway, just making sure nobody's going to accuse me of saying OpenStack 
should abandon all RDBMS use for a KVS. :)

Best,
-jay

> Some pointers:
> 
> https://github.com/beyondtheclouds/rome
> 
> https://www.openstack.org/videos/austin-2016/a-ring-to-rule-them-all-revising-openstack-internals-to-operate-massively-distributed-clouds 
> 
>