Client port found: 2181. Client address: localhost. Error contacting service. It is probably not running

問題：
異常信息：啟動zookeeper時提示Starting zookeeper … already running as process 2502.
使用命令./zkServer.sh status查看狀態顯示ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/…/conf/zoo.cfg
Client port found: 2181. Client address: localhost.
Error contacting service. It is probably not running.
通過瀏覽conf中zoo.cfg文件發現配置沒問題。

解決辦法1：通過命令進入cd /usr/local/zookeeper/data中找到zookeeper_server.pid文件進行刪除，然后重新啟動zookeeper即可

解決辦法2：關閉防火牆，systemctl stop firewalld.service，重啟zookeeper。