kafka0.10->flume1.8->elasticsearch 6.0 自定义日志解析类，自定义索引名,Kafkasource 修改从最后ｏｆｆｓｅｔ开始读。　(Kafka 0.10 to flume 1.8 to elasticsearch 6 Customize the log parsing class, customize the index name, and read the Kafkasource changes from the last offset.)