On 04/28/2016 08:25 PM, Edward Leafe wrote:
Your own tests showed that a single RDBMS instance doesn’t even break a sweat under your test loads. I don’t see why we need to shard it in the first place, especially if in doing so we add another layer of complexity and another dependency in order to compensate for that choice. Cells are a useful concept, but this proposed implementation is adding way too much complexity and debt to make it worthwhile.
now that is a question I have also. Horizontal sharding is usually for the case where you need to store say, 10B rows, and you'd like to split it up among different silos. Nothing that I've seen about Nova suggests this is a system with any large data requirements, or even medium size data (a few million rows in relational databases is nothing). I didn't have the impression that this was the rationale behind Cells, it seems like this is more of some kind of logical separation of some kind that somehow suits some environments (but I don't know how). Certainly, if you're proposing a single large namespace of data across a partition of nonrelational databases, and then the data size itself is not that large, as long as "a single namespace" is appropriate then there's no reason to break out of more than one MySQL database. There's not much reason to transparently shard unless you are concerned about adding limitless storage capacity. The Cells sharding seems to be intentionally explicit and non-transparent.
-- Ed Leafe __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
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