84 points by aphyr 6 hours ago | 6 comments
fluxcorethread 50 minutes ago
I don't understand why, if you are creating a distributed db, that you don't at least try using eg. aphyrs jepsen library (1).

The story seems to repeat itself for distributed database: Documentation looks more like advertisement. Promises a lot but contains multiple errors, and failures that can corrupt the data. It's great that jepsen doing the work they do!

1. https://github.com/jepsen-io/jepsen

jwr 44 minutes ago
It also surprises me. Every company that creates a distributed database should pay for Jepsen testing. First, it is a great chance to improve their software, and second, if there are problems, they will eventually come to light anyway.
taneliv 4 hours ago
While Jepsen (and this article) is focused on behavior under node failure and network partitions, this caught my eye:

> It also exhibits Stale Read, Lost Update, and other forms of G-single in healthy clusters

This looks like quite a fundamental issue.

mono442 2 hours ago
I would kinda expect that. MySQL hasn't been designed to be a distributed database from the beginning and it's usually hard to make it work later on.
linsomniac 6 hours ago
I really like glaera for low volume clustering, because of the true multi-master nature. I've been using it for over a decade on a clustered mail server for storing account information, and more recently I've pumped the log information in there so each user can see their related log messages, for a user base of around 6,000 users, and it's been a real workhorse.
ffsm8 1 hour ago
Uh, that scale doesn't even need clustering beyond high availability.

And as Jepsen showed, if you actually do increase volume, it loses consistency... Invalidating the use case for multi master entirely. So, ymmv I guess

constructrurl 6 hours ago
[flagged]
linsomniac 6 hours ago
I realize that we like to use the page title here on HN, but this really should be something like "Data loss cases with MariaDB Glaera Cluster 12.1.2".
6 hours ago
hu3 5 hours ago
One of the reasons is that this kind of title editorialization fosters generic commentaries in reaction to titles.