>I think Google’s Zanzibar is also centralized but leverages extreme caching to get lower latencies?
That's correct. In a Zanzibar-like model, you have a global storage, but individual clusters in each datacenter/edge providing consistency-aware caching. This means p99 can be something like 25ms, but p95 or p50 is often FAR lower.
Disclosure: I'm a co-creator and maintainer of SpiceDB[0]
I’ve watched y’all’s Papers We Love talk about Zanzibar and have recommended authzed to organizations bootstrapping permission modeling.
It’s been awhile, is the gist that Spanner’s coordinated clocks allow tighter consensus (i.e. faster writes) and caching provides read-my-write consistency?
Thanks for watching our presentation and recommending our solution.
Unfortunately, nothing is ever simple; comparing Spanner and CockroachDB is comparing apples to oranges. Two years ago, we wrote an article that details exactly how the differences matter in terms of a Zanzibar implementation[0], but I can give as short of a summary as possible: Spanner is linearizable and CockroachDB only guarantees external consistency for transactions that share rows. The post outlines how we workaround this and we've also more recently talked about how we've managed to scale that to 1M requests per second[1]. Our team focuses a lot on CockroachDB because we offer a permission systems that can span not only regions within a single cloud, but across various cloud providers. However, if you're all in on GCP, SpiceDB itself supports Cloud Spanner (which we also use in production for our GCP-only customers).
I can attest to that statement: comparing Spanner and CockroachDB is difficult. Spanner and Fauna (where I work) are more comparable (Fauna is based on Calvin, see [0]) since they both support strict serializability (in different ways). The article referenced here is excellent, and it highlights what we've seen from some customers: CockroachDB is (to say the least) a challenge to learn and adequately deploy, I've seen a few others that have a similar lessons-learned result. I'm glad, however, that highly consistent distributed databases provide value in these implementations. Although not OSS, Fauna is comparable and more turnkey (read: much less ops) than these options.
That's correct. In a Zanzibar-like model, you have a global storage, but individual clusters in each datacenter/edge providing consistency-aware caching. This means p99 can be something like 25ms, but p95 or p50 is often FAR lower.
Disclosure: I'm a co-creator and maintainer of SpiceDB[0]
[0]: https://github.com/authzed/spicedb