4 ms·
2-3x maybe, 10x not likely, unless you compare it to untuned cassandra. What makes it possible to run cassandra/scylla on nodes with TBs of data density is the
by throwdbaaway 6y ago
2-3x maybe, 10x not likely, unless you compare it to untuned cassandra.
What makes it possible to run cassandra/scylla on nodes with TBs of data density is the TWCS compaction strategy from Jeff Jirsa. He was just a cassandra power user at the time, and I like to think that the invention was possible because of Java.
So, next time you read an ad piece from scylla about replacing 40 mid size boxes running CMS with 4 big boxes, don't forget about TWCS.
- manigandham 6y agoIt's 4 servers doing the same as 40. That is 10x throughput, and with lower tail latency. Scylla is far more than a compaction strategy. If it was that simple, than Cassandra would already be able to do it. It's an objectively faster database in every metric. Datastax's enterprise distribution has more functionality but core Cassandra is now entirely outclassed by Scylla in speed and features.
- throwdbaaway 6y agoAgain, that's 40 mid size boxes with questionable GC (32G to 48G heap size is the no man land, G1GC target pause time of 500ms of course will result in 500ms P999 latency, etc), versus 4 big boxes, which have more than 4x higher specs. So 10 divides by 4, that's the 2-3x that I mentioned. The TWCS is just a good example that raw performance is not everything. Performance also comes from things like compaction strategy, data modeling, and access pattern, while users and stakeholders also care about things like easiness to modify, friendly license, and steady stewardship.
- deleted 6y ago[deleted]