Default parallel concurrency of 50 is too high

[wdroste]

Expected Behavior (Mandatory)

For parallel often times there's only 4 CPU or if there's 50 CPU its just too many threads. I would expect a default of 4. apoc.iterate('delete query', { batchSize: 1000, parallel: true})

I expected this to be 4-6

Actual Behavior (Mandatory)

The actual behavior is 50 threads, which either tends to lock on deletes or over tax the system

How to Reproduce the Problem

Run a delete on 1m nodes on a small box.

apoc.iterate("MATCH (n)", "DETACH DELETE n", { batchSize: 1000, parallel: true})

Versions

• OS: NA
• Neo4j: 4.0+
• Neo4j-Apoc: 4.0+