private static boolean tablesOnMaster() {
    boolean ret = true;
    String value = util.getConfiguration().get("hbase.balancer.tablesOnMaster");
    if (value != null && value.equalsIgnoreCase("none")) {
      ret = false;
    }
    return ret;
  }
The load test tool used to create load and make sure that WALs aren't empty.
hbase-it/src/test/java/org/apache/hadoop/hbase/mttr/IntegrationTestMTTR.java