[HADOOP-16013] DecayRpcScheduler decay thread should run as a daemon

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.0
• Fix Version/s: 2.10.0, 3.3.0, 3.1.4, 3.2.2
• Component/s: ipc
• Target Version/s: 2.10.0
• Assignee: Erik Krogen
• Reporter: Erik Krogen
• Created: 18/Dec/18 17:55
• Updated: 05/Nov/19 01:19
• Resolved: 11/Jan/19 20:58

Description

DecayRpcScheduler sets up a Timer to schedule a decay of the weights it tracks:

    // Setup delay timer
    Timer timer = new Timer();
    DecayTask task = new DecayTask(this, timer);
    timer.scheduleAtFixedRate(task, decayPeriodMillis, decayPeriodMillis);

However this Timer is not set up as a daemon thread. I have seen this cause my JVM to refuse to exit when running, for example, NNThroughputBenchmark with FairCallQueue enabled.