一、zookeeper超出最大连接限制：ambari server检测到critical错误, zookeeper server on ep-bd01:2181 连接被积极拒绝，翻看主机上zookeeper的日志
tail -n200 zookeeper-zookeeper-server-ep-bd01.out，发现都是如下错误：
-- ::, [myid:] - WARN [NIOServerCxn.Factory:0.0.0.0/0.0.0.0::NIOServerCnxnFactory@] - Too many connections from /192.168.58.11 - max is
-- ::, [myid:] - WARN [NIOServerCxn.Factory:0.0.0.0/0.0.0.0::NIOServerCnxnFactory@] - Too many connections from /192.168.58.11 - max is
搜索后，在ambari界面上添加如下参数[maxClientCnxns]，问题解决：