echo stat | nc localhost 2181 | grep Mode
You will get the response if the node is acting as a leader:
Mode: leader
If it is a follower, you will see:
Mode: follower
Alternatively, you can use the zkServer.sh located in /opt/zookeeper/bin:
./zkServer.sh status
[root@misc010-prod ~]# echo mntr |nc 10.16.1.60 2181 zk_version 3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f, built on 03/23/2017 10:13 GMT zk_avg_latency 0 zk_max_latency 2 zk_min_latency 0 zk_packets_received 36275 zk_packets_sent 36274 zk_num_alive_connections 2 zk_outstanding_requests 0 zk_server_state leader zk_znode_count 488 zk_watch_count 3 zk_ephemerals_count 4 zk_approximate_data_size 40646 zk_open_file_descriptor_count 33 zk_max_file_descriptor_count 65536 zk_followers 2 zk_synced_followers 2 zk_pending_syncs 0 [root@misc010-prod ~]# echo mntr |nc 10.16.1.21 2181 zk_version 3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f, built on 03/23/2017 10:13 GMT zk_avg_latency 0 zk_max_latency 10 zk_min_latency 0 zk_packets_received 685 zk_packets_sent 686 zk_num_alive_connections 1 zk_outstanding_requests 0 zk_server_state follower zk_znode_count 488 zk_watch_count 0 zk_ephemerals_count 4 zk_approximate_data_size 40646 zk_open_file_descriptor_count 30 zk_max_file_descriptor_count 1048576 [root@misc010-prod ~]# echo mntr |nc 10.16.1.22 2181 zk_version 3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f, built on 03/23/2017 10:13 GMT zk_avg_latency 0 zk_max_latency 13 zk_min_latency 0 zk_packets_received 73614 zk_packets_sent 73622 zk_num_alive_connections 3 zk_outstanding_requests 0 zk_server_state follower zk_znode_count 488 zk_watch_count 37 zk_ephemerals_count 4 zk_approximate_data_size 40646 zk_open_file_descriptor_count 32 zk_max_file_descriptor_count 1048576
在 leader 输出中
zk_followers 2
zk_synced_followers 2
zk_pending_syncs 0
表示 zk 正常