Hi there, I've been trying to upgrade a Cassandra 3.9 cluster to Cassandra 3.11. Whenever I try to add a new Cassandra 3.11 node to the main datacenter, using `-Dcassandra.force_3_0_protocol_version=true` on the new node, this new node uses almost 100% of its CPU. Checking `nodetool compactionstats -H`, I can see there is always pending compacting tasks.
t0: ``` [aladdin@ip-172-16-1-10 ~]$ nodetool compactionstats -H pending tasks: 11 - x.morning: 9 - y.afternoon: 2 id compaction type keyspace table completed total unit progress b0f174d0-8671-10e8-8429-114a220c107d Compaction x morning 170.15 MiB 23.64 GiB bytes 0.70% 38b02640-8439-10e8-8429-114a220c107d Compaction y afternoon 2.55 GiB 40.17 GiB bytes 6.35% Active compaction remaining time : 1h05m09s ``` t1: ``` [aladdin@ip-172-16-1-10 ~]$ nodetool compactionstats -H pending tasks: 11 - x.morning: 9 - y.afternoon: 2 id compaction type keyspace table completed total unit progress b0f174d0-8671-10e8-8429-114a220c107d Compaction x morning 404.3 MiB 23.64 GiB bytes 30.20% 38b02640-8439-10e8-8429-114a220c107d Compaction y afternoon 2.55 GiB 40.17 GiB bytes 6.35% Active compaction remaining time : 1h04m55s ``` t2: ``` [aladdin@ip-172-16-1-10 ~]$ nodetool compactionstats -H pending tasks: 8 - system.size_estimates: 1 - x.morning: 4 - y.afternoon: 3 id compaction type keyspace table completed total unit progress 38b02640-8439-10e8-8429-114a220c107d Compaction y afternoon 2.55 GiB 40.17 GiB bytes 6.35% 06f3a660-867b-10e8-8429-114a220c107d Compaction x morning 538.04 MiB 11.15 GiB bytes 4.71% ``` `38b02640-8439-10e8-8429-114a220c107d` seems to be stuck at 6.35% for the last 4 days and y. morning keeps compacting forever, always with a different id. Nodes are configured to run via `GossipingPropertyFileSnitch` on a i3.large (AWS) and this problem seems to happen only on the main datacenter. The secondary datacenter has one node running `Cassandra 3.9` and one node running `Cassandra 3.11` without any further issues. Have you guys faced this problem before? Thanks in advance! Igor
