public static String getDefaultCodec(final Configuration c) {
    // If "hbase.client.default.rpc.codec" is empty string -- you can't set it to null because
    // Configuration will complain -- then no default codec (and we'll pb everything). Else
    // default is KeyValueCodec
    return c.get(DEFAULT_CODEC_CLASS, KeyValueCodec.class.getCanonicalName());
  }
Construct an IPC client for the cluster <code>clusterId</code>
@param conf      configuration
@param clusterId the cluster id
@param localAddr client socket bind address.
@param metrics   the connection metrics
hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java