How stable is Cassandra?s

Question

I've been using Cassandra instance without reboot for a few days for a simple task for storing tweets, 1-2 saves in a second. After then Cassandra got really slow and I had to kill a restart it. Is this Cassandras's expected stability now? Would it be a good solution to write a daemon to kill/restart it every day or two?

Answer 1

No. Cassandra is widely expected to be more stable than that. If it is not stable, there is a substantial chance you have configured it wrong. It may be attempting to use more memory than you expect, for instance. If you have encountered a bug or defect in Cassandra, it is not one which is afflicting the majority of users.

As for your "restart daemon" plan, I'm going to go with "that's a horrible solution for pretty much everything, and especially so for something that you're trusting with any data you actually care about."

Answer 2

From https://cassandra.apache.org/

Cassandra is in use at Netflix, Twitter, Urban Airship, Constant Contact, Reddit, Cisco, OpenX, Digg, CloudKick, Ooyala, and more companies that have large, active data sets. The largest known Cassandra cluster has over 300 TB of data in over 400 machines.

It was (is?) largely used at Facebook too. I would say it's stable. :)

And btw, I don't think it's meant to be restarted every 1-2 days at all: you use it if you have huge data sets with high availability (HA) requirements, and going down every 2 days is not HA.