錯誤信息：
Sending Logstash logs to /usr/local/logstash-6.4.3/logs which is now configured via log4j2.properties
[2019-07-14T17:37:06,988][FATAL][logstash.runner ] Logstash could not be started because there is already another instance using the configured data directory. If you wish to run multiple instances, you must change the "path.data" setting.
[2019-07-14T17:37:07,010][ERROR][org.logstash.Logstash ] java.lang.IllegalStateException: Logstash stopped processing because of an error: (SystemExit) exit
解決方法：
進到 data 目錄，刪除目錄下的緩存 .lock 。如下圖所示。
重新啟動kibana