@Test
  public void test() {
    assertTrue(normalizer.isMergeEnabled());
    assertEquals(3, normalizer.getMergeMinRegionCount());
    assertEquals(1_000_000L, parseConfiguredRateLimit(worker.getRateLimiter()));

    final Configuration newConf = new Configuration(conf);
    // configs on SimpleRegionNormalizer
    newConf.setBoolean("hbase.normalizer.merge.enabled", false);
    newConf.setInt("hbase.normalizer.merge.min.region.count", 100);
    // config on RegionNormalizerWorker
    newConf.set("hbase.normalizer.throughput.max_bytes_per_sec", "12g");

    configurationManager.notifyAllObservers(newConf);
    assertFalse(normalizer.isMergeEnabled());
    assertEquals(100, normalizer.getMergeMinRegionCount());
    assertEquals(12_884L, parseConfiguredRateLimit(worker.getRateLimiter()));
  }
Test that configuration changes are propagated to all children.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/normalizer/TestRegionNormalizerManagerConfigurationObserver.java