How to check the number of cores that Spark uses?

Question

I have spark.cores.max set to 24 [3 work nodes], but if I get into my work node and see that there is only one process [command = Java] that consumes memory and processor. I suspect that it does not use all 8 cores (on m2.4x large ).

How to find out the number?

Answer 1

You can see the number of cores occupied for each worker in a cluster in the Spark Web interface: