High CPU in ScheduledThreadPoolExecutors with 0 corePoolSize

Solution Verified - Updated

Environment

  • Java 8
  • OpenJDK 8

Issue

  • We see high CPU in our application with a ScheduledThreadPoolExecutor if it is configured with a corePoolSize of 0
   java.lang.Thread.State: RUNNABLE
	at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.poll(ScheduledThreadPoolExecutor.java:809)
	at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1073)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:750)

Resolution

  • Use a corePoolSize of at least 1 or higher
  • Update to Java 9+

Root Cause

SBR
Product(s)
Components
Category
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