private Map<String, GcTimes> getGcTimes() {
    Map<String, GcTimes> map = Maps.newHashMap();
    List<GarbageCollectorMXBean> gcBeans = ManagementFactory.getGarbageCollectorMXBeans();
    for (GarbageCollectorMXBean gcBean : gcBeans) {
      map.put(gcBean.getName(), new GcTimes(gcBean));
    }
    return map;
  }
log INFO if we detect a pause longer than this threshold
hbase-server/src/main/java/org/apache/hadoop/hbase/util/JvmPauseMonitor.java