Hi, I'm not sure if this will help, but I tried today to change one node to 3.11.9 from 3.11.6. We are NOT using TWCS. Very heavy read pattern, almost no writes, with constant performance test load. Cassandra read latency 99% increased significantly, but NOT on the node where I changed version (top line 90ms vs normal 2ms).. Getting back to 3.11.6 immediately fixed the issue. Interesting would be to check all nodes on the new version, but I cannot do such a test for several weeks. At least in a mixed cluster this is no go.
Regards, Maxim. [image: image.png]
