private static <T extends ReplicationService> T newReplicationInstance(String classname,
    Class<T> xface, Configuration conf, HRegionServer server, FileSystem walFs, Path logDir,
    Path oldLogDir, WALFactory walFactory) throws IOException {
    final Class<? extends T> clazz;
    try {
      ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
      clazz = Class.forName(classname, true, classLoader).asSubclass(xface);
    } catch (java.lang.ClassNotFoundException nfe) {
      throw new IOException("Could not find class for " + classname);
    }
    T service = ReflectionUtils.newInstance(clazz, conf);
    service.initialize(server, walFs, logDir, oldLogDir, walFactory);
    return service;
  }
Load the replication executorService objects, if any
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java