Following is my architecture 2 Servers: Server 1: running Apache Nifi + Zookeeper (Not embedded) Server 2: running Apache Nifi + Zookeeper (Not embedded) To test failovers, I close down the Server that has been selected as Cluster Coordinator In this case, zookeeper should automatically elect the remaining one server as leader. But it keeps failing and goes into continuous loop of trying to connect to the first server Zookeeper Logs in Server 2 when leader (Server 1) went down: 2019-10-22 18:44:01,135 [myid:2] - WARN [NIOWorkerThread-2:NIOServerCnxn@370] - Exception causing close of session 0x0: ZooKeeperServer not running 2019-10-22 18:44:02,925 [myid:2] - WARN [NIOWorkerThread-3:NIOServerCnxn@370] - Exception causing close of session 0x0: ZooKeeperServer not running 2019-10-22 18:44:03,320 [myid:2] - WARN [QuorumPeer[myid=2](plain=/0:0:0:0:0:0:0:0:2181)(secure=disabled):QuorumCnxManager@677] - Cannot open channel to 1 at election address ec2-server-1.compute-1.amazonaws.com/172.xx.x.x:3888 java.net.ConnectException: Connection refused (Connection refused) at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) Server 2 Config files: zoo.cfg tickTime=2000 initLimit=5 syncLimit=2 dataDir=/home/ec2-user/zookeeper clientPort=2181 server.1=ec2-server-1.compute-1.amazonaws.com:2888:3888 server.2=0.0.0.0:2888:3888 nifi.properties nifi.cluster.is.node=true nifi.cluster.node.address=ec2-server-2.compute-1.amazonaws.com nifi.cluster.node.protocol.port=8082 nifi.cluster.flow.election.max.wait.time=2 mins nifi.cluster.flow.election.max.candidates=1 # zookeeper properties, used for cluster management # nifi.zookeeper.connect.string=localhost:2181 nifi.zookeeper.root.node=/nifi Server 1 Config files: zoo.cfg tickTime=2000 initLimit=5 syncLimit=2 dataDir=/home/ec2-user/zookeeper clientPort=2181 server.1=0.0.0.0:2888:3888 server.2=ec2-server-2.compute-1.amazonaws.com:2888:3888 nifi.properties nifi.cluster.is.node=true nifi.cluster.node.address=ec2-server-1.compute-1.amazonaws.com nifi.cluster.node.protocol.port=8082 nifi.cluster.flow.election.max.wait.time=2 mins nifi.cluster.flow.election.max.candidates=1 # zookeeper properties, used for cluster management # nifi.zookeeper.connect.string=localhost:2181 nifi.zookeeper.root.node=/nifi What am I doing wrong? ... View more