OptionalapplyOptionalapply_Maximum number of "apply parts" tasks that can be performed in parallel during catchup. We set this to a very low value to avoid overloading the node while it is still performing normal tasks.
Optionalpeer_Maximum number of outstanding requests for decentralized state sync.
Optionalper_The maximum parallelism to use per shard. This is mostly for fairness, because the actual rate limiting is done by the TaskTrackers, but this is useful for balancing the shards a little.
Maximum number of "apply parts" tasks that can be performed in parallel. This is a very disk-heavy task and therefore we set this to a low limit, or else the rocksdb contention makes the whole server freeze up.