Hey guys, We've been having issues in the past couple of days with CPU usage / load average suddenly skyrocketing on some nodes of the cluster, affecting performance significantly so majority of requests start timing out. It can go on for several hours, with CPU spiking through the roof then coming back down to norm and so on. Weirdly, it affects only a subset of nodes and it's always the same ones. The boxes Cassandra is running on are pretty beefy, 24 cores, and these CPU spikes go up to >1000%.
What is the best way to debug such kind of issues and find out what Cassandra is doing during spikes like this? Doesn't seem to be compaction related as sometimes during these spikes "nodetool compactionstats" says no compactions are running. Thanks!
