Boring but parallel loops in Scala using "foreach" method

aws_sdk_v2_ecs_config_foreach_method.scala

import java.util.concurrent.TimeUnit

import software.amazon.awssdk.services.ecs.EcsClient
import software.amazon.awssdk.services.ecs.model.{DescribeServicesRequest, ListServicesRequest}

import scala.collection.JavaConverters._

object EcsAutoScalingReport extends App {
  val startTime = System.nanoTime()

  var ecs = EcsClient.create()
  // 92 services collected in
  // Sequential for(...): 11/14/7/13/12/15 secs
  // 1 for(...par): 9/10/10/10 secs
  // 2 for(...par): 5/5/5/5/6 secs
  // 3 for(...par): 5/6/5/5/5 secs
  // 2 .par.foreach{}: 6/5/5/5/5 secs
  ecs.listClustersPaginator().clusterArns().asScala.par.foreach { ecsClusterArn =>
    ecs.listServicesPaginator(ListServicesRequest.builder()
      .cluster(ecsClusterArn)
      .build())
      .serviceArns().asScala.grouped(10).toParArray.foreach { ecsServiceArns =>
        ecs.describeServices(DescribeServicesRequest.builder()
          .cluster(ecsClusterArn)
          .services(ecsServiceArns.asJavaCollection)
          .build())
          .services().asScala.foreach { ecsService =>
            println(ecsService.serviceName())
        }
    }
  }

  val timeTakenSec = TimeUnit.NANOSECONDS.toSeconds(System.nanoTime() - startTime)
  println(s"DONE in $timeTakenSec secs")
}