@sidharth mishra This is just a WARN and it is kind of expected by design. org.apache.zookeeper.server.quorum.QuorumCnxManager class implements a connection manager for leader election using TCP. It maintains one connection for every pair of servers. The tricky part is to guarantee that there is exactly one connection for every pair of servers that are operating correctly and that can communicate over the network. If two servers try to start a connection concurrently, then the connection manager uses a very simple tie-breaking mechanism to decide which connection to drop based on the IP addressed of the two parties. For every peer, the manager maintains a queue of messages to send. If the connection to any particular peer drops, then the sender thread puts the message back on the list. As this implementation currently uses a queue implementation to maintain messages to send to another peer, we add the message to the tail of the queue, thus changing the order of messages. Although this is not a problem for the leader election, it could be a problem when consolidating peer communication. If this response clarifies it, vote/accept it as the answer. ... View more