Hi, We're using Cassandra, recently migrated to 2.1.6, and we're experiencing constant OOMs in one of our clusters.
It's a rather small cluster: 3 nodes, EC2 xlarge: 2CPUs, 8GB RAM, set up with datastax AMI. Configs (yaml and env.sh) are rather default: we've changed only concurrent compactions to 2 (although tried 1, too), tried setting HEAP and NEW to different values, ranging from 4G/200 to 6G/200M. Write load is rather small: 200-300 small payloads (4 varchar fields as a primary key, 2 varchar fields and a couple of long/double fields), plus some larger (1-2kb) payloads with a rate of 10-20 messages per second. We do a lot of range scans, but they are rather quick. It kind of started overnight. Compaction is taking a long time. Other two nodes in a cluster behave absolutely normally: no hinted handoffs, normal heap sizes. There were no write bursts, no tables added no indexes changed. Anyone experienced something similar? Maybe any pointers? -- alex p
