@BeforeClass
  public static void beforeClass() throws Exception {
    Configuration conf = HTU.getConfiguration();
    conf.setFloat("hbase.regionserver.logroll.multiplier", 0.0003f);
    conf.setInt("replication.source.size.capacity", 10240);
    conf.setLong("replication.source.sleepforretries", 100);
    conf.setInt("hbase.regionserver.maxlogs", 10);
    conf.setLong("hbase.master.logcleaner.ttl", 10);
    conf.setInt("zookeeper.recovery.retry", 1);
    conf.setInt("zookeeper.recovery.retry.intervalmill", 10);
    conf.setBoolean(ServerRegionReplicaUtil.REGION_REPLICA_REPLICATION_CONF_KEY, true);
    conf.setLong(HConstants.THREAD_WAKE_FREQUENCY, 100);
    conf.setBoolean("hbase.tests.use.shortcircuit.reads", false);
    conf.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 5); // less number of retries is needed
    conf.setInt(HConstants.HBASE_CLIENT_SERVERSIDE_RETRIES_MULTIPLIER, 1);

    HTU.startMiniCluster(NB_SERVERS);
  }
Tests region replication by setting up region replicas and verifying async wal replication
replays the edits to the secondary region in various scenarios.
hbase-server/src/test/java/org/apache/hadoop/hbase/replication/regionserver/TestRegionReplicaReplication.java