Hi I'm having a problem after upgrading Cassandra 3.0.14 to 3.11.1. When running a repair the node I'm issuing the repair starts to use use all available memory and then the GC grinds it to death. I'm seeing with nodetool compactionstats that there is a lot of (> 100) active concurrent compaction jobs typed 'Validation'.
I'm running the repair with `nodetool repair -pr -seq keyspace table` Cassandra has 18G max heap memory, but that doesn't seem to be even close to enough. With visualvm I can see that big portion of the live heap is used on the validation's objects: https://imgur.com/U0WUWEs MerkleTree$Inner: 5G MerkleTree$Leaf: 3.2G Murmur3Partitioner$LongToken: 2.5G Any ideas?
