public HdfsSystemDescriptor withWriteBatchSizeBytes(long writeBatchSizeBytes) {
    this.writeBatchSizeBytes = Optional.of(writeBatchSizeBytes);
    return this;
  }
Split output files from all writer tasks based on # of bytes written to optimize
MapReduce utilization for Hadoop jobs that will process the data later.
@param writeBatchSizeBytes write batch size in bytes.
@return this system descriptor
samza-hdfs/src/main/java/org/apache/samza/system/hdfs/descriptors/HdfsSystemDescriptor.java