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Is it normal for people to run Cassandra on only 3 nodes in production environments? I realize that one of the selling points is starting small and then scalin
by jfager 16y ago
Is it normal for people to run Cassandra on only 3 nodes in production environments? I realize that one of the selling points is starting small and then scaling out without any headaches, but 3 nodes seems extreme in that regard.
- jbellis 16y agoWell, roughly speaking, you can group Cassandra deployments in two categories+: new products that are hoping they need Cassandra's scaling ability someday, and existing products moving to Cassandra from something else because the pain of scaling something that wasn't designed to makes them. The first category will start small. The smallest production deployment I know is a single 256MB VM, but usually even starting small you should not have less than 2 servers (why tempt fate with a non-redundant setup when Cassandra makes it so easy to be safe?). The second group is where you see larger deployments out of the gate. 3 machines does seem small for reddit; I guess they made up the difference with memcached. Unfortunately they deployed just before the 0.6.0 final release was out, which is where we added the row cache feature that could have made memcached unnecessary. +There are people using cassandra for non-scale-related reasons, though. Most of these people are motivated by multi-datacenter replication.