We are using the Spark Cassandra driver, version 1.2.0 (Spark 1.2.1) connecting to a 6 node bare metal (16gb ram, Xeon E3-1270 (8core), 4x 7,2k SATA disks) Cassandra cluster. Spark runs on a separate Mesos cluster.
We are running a transformation job, where we read the complete contents of a table into Spark, do some transformations and write them back to C*. We are using Spark to do a data migration in C*. Before we execute, the load on Cassandra is very little. We notice incredibly slow reads, 600mb in an hour, we are using quorum LOCAL_ONE reads. The load_one of Cassandra increases from <1 to 60! There is no CPU wait, only user & nice. The table & cassandra.yaml: https://gist.github.com/nathan-gs/908a48aed8a0eb3c3183 Anyone any idea? Thanks, Nathan
