Mikio L. Braun shares a set of experiments he ran configuring the garbage collection for Cassandra:

In summary, a bit of garbage collection tuning can help to make Cassandra run in a stable manner. In particular, you should set the CMS thresholds a bit lower, and probably also experiment with incremental CMS if you have enough cores. Setting the CMS threshold to 75%, I got Cassandra to run well in 8GB without any GC induced glitches, which is a big progress from the previous post.

Jonathan Ellis has recently mentioned a valuable resource for Garbage Collection tuning, a presentation by Tony Printezis, Charlie Hunt and Ludovic Poitou: “Garbage Collection Tuning in the Java HotSpot Virtual Machine” (nb unfortunately the link is not available anymore, but if you can find it somewhere make sure you get a copy). Also to note that the last Cassandra release went outside the VM dealing directly with the OS for addressing a combination of GC behavior and swapping.

Original title and link for this post: Cassandra: Tuning Garbage Collection (published on the NoSQL blog: myNoSQL)

via: http://blog.mikiobraun.de/2010/08/cassandra-gc-tuning.html