Hi, Regarding shared pool workers see CASSANDRA-11966. You may have to backport it depending on your Cassandra version. Did you try to lower compaction throughput to see if it helps? Be sure to keep an eye on pending compactions, SSTables count and SSTable per read of course. "alloc" is the memory allocation rate. You can see that compactions are GC intensive. You won't be able to achieve impressive writes/s with LWT. But maybe there is room for improvement. Try GC tuning, different pool sizes for NTR, concurrent reads and writes, compaction executors, etc. Also check if you can improve network latency (e.g. VF or ENA on AWS). What LWT rate would you want to achieve? Best, Romain
Le Lundi 27 février 2017 12h48, Kant Kodali <k...@peernova.com> a écrit : Also Attached is a flamed graph generated from a thread dump. On Mon, Feb 27, 2017 at 2:32 AM, Kant Kodali <k...@peernova.com> wrote: Hi, Attached are the stats of my Cassandra node running on a 4-core CPU. I am using sjk-plus tool for the first time so what are the things I should watched out for in my attached screenshot? I can see the CPU is almost maxed out but should I say that is because of compaction or shared-worker-pool threads (which btw, I dont know what they are doing perhaps I need to take threadump)? Also what is alloc for each thread? I have a insert heavy workload (almost like an ingest running against cassandra cluster) and in my case all writes are LWT. The current throughput is 1500 writes/sec where each write is about 1KB. How can I tune something for a higher throughput? Any pointers or suggestions would help. Thanks much,kant