With below tests I was trying to measure Cassandra write performance. First off this is probably not a good performance comparison for a number of reasons. Main one being I was running this on my laptop. If you ran this on server grade hardware with a tuned Cassandra setup you probably would get higher numbers. That being said, this was done to get a general idea about write performance in Cassandra ‘cos “You can’t do much without measuring”.
My setup was,
- Cassandra running in a VirtualBox VM with default parameters. Only the data directories were changed
- VM was running Kubuntu 11.04
- JDK 1.6.0_27
- JVM was not warmed up before carrying out the test. I started Cassandra with an empty keyspace for each case
- I was testing the code hosted here
Here’s how the three column families look like.
REGData column family,
PropertyIndex column family,
TagIndex column family,
Here are the results,
The graphs looks very similar. However Cassandra 1.0.2 is has faster write speeds. Here are the raw data. T in the graph represent number of tags and P number of properties.
Sudden spike in write speed increase is a bit scary. That can be due to I/O bottleneck in the machine. At that point my disk started grinding heavily. During the time of the tests, I didn’t do any other disk intensive tasks. On server grade hardware with a few fast disks results might be different. Radically even.