[KAFKA-2613] Consider capping `maxParallelForks` for Jenkins builds

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.9.0.0
• Component/s: build
• Assignee: Ewen Cheslack-Postava
• Reporter: Ismael Juma
• Reviewer: Gwen Shapira
• Created: 06/Oct/15 11:14
• Updated: 13/Oct/15 02:11
• Resolved: 13/Oct/15 02:11

Description

We currently set `maxParallelForks` to the number returned by `Runtime.availableProcessors`.

  tasks.withType(Test) {
    maxParallelForks = Runtime.runtime.availableProcessors()
  }

This returns the number of logical cores (including hyperthreaded cores) in the machine.

This is usually OK when running the tests locally, but the Apache Jenkins slaves run 2 to 3 jobs simultaneously causing a higher number of timing related failures.

A potential solution is to allow `maxParallelForks` to be set via a Gradle property and use that property to set it to an appropriate value when the build is run from Jenkins.