Forgot to mention that i'm using default STCS for all tables
---- On Sun, 06 Mar 2022 12:29:52 +0330 onmstester onmstester <onmstes...@zoho.com> wrote ---- Hi, Sometimes compactions getting so slow (a few KBs per second for each compaction) on a few nodes which would be fixed temporarily by restarting restarting cassandra (although would coming back a few hours later). Copied sstables related to slow compactions to a isolated/single node cassandra, and there, they are fast. Using Set<text> as non-key column I suspect one table with big partitions (1000 rows, each row has a Set which sum of set size for all rows in a big partitions is 10M), but disabling autocompaction for this table didn't help. There are no obvious hardware resource shortage, resource consumptions of all nodes in cluster is identical but only a few of nodes has slow compactions. I'm using Apache Cassandra 3.11.2. A few related configs: concurrent compactors: 5 throughput: 64MB tables count: 20 + default tables Disk: 7.2K CPU: 12 cores with 50% usage Anyone experienced similar problems with compactions? Is there any related bug which would be fixed by upgrading? How can i find out the root cause of this problem? Best Regards