[SOLR-16066] Fix unmanaged Thread in ZkController

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Assignee: Unassigned
• Reporter: Houston Putman
• Created: 01/Mar/22 20:28
• Updated: 04/May/22 18:46
• Resolved: 04/May/22 18:46

Description

Currently the following is used to in ZKController.fireListeners()

new Thread(() -> {
  log.debug("Running listeners for {}", zkDir);
  for (final Runnable listener : listenersCopy) {
    try {
      listener.run();
    } catch (Exception e) {
      log.warn("listener throws error", e);
    }
  }
}, "ZKEventListenerThread").start(); 

This causes leaked threads in a variety of tests. We should either start to use a separate thread pool for this (and possibly run each listener in a separate thread), or merely run it in the same thread.

Issue Links

• duplicates: SOLR-16154 ZKEventListenerThread leaks from tests