synchronized void stop() {
    stopped = true;
    notifyAll();
  }
Thread safe utility that keeps registry end points used by {@link ConnectionRegistry} up to date.
By default the refresh happens periodically (configured via {@code intervalSecsConfigName}). The
refresh can also be triggered on demand via {@link #refreshNow()}. To prevent a flood of
on-demand refreshes we expect that any attempts two should be spaced at least
{@code minIntervalSecsConfigName} seconds apart.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegistryEndpointsRefresher.java