Linux中的命令NetCat有“瑞士军刀”的美誉。我们可以通过nc命令查看Zookeeper的一行属性数据。在Zookeeper中有很多四字命令，汇总如下：
| 序号 | 使用命令 | 输出说明 |
| 1 | echo conf | nc 10.9.3.253 2181 | 输出Zookeeper相关服务的详细配置信息，如客户端端口，数据存储路径、最大连接数、日志路径、数据同步端口、主节点推举端口、session超时时间等等 |
| 2 | echo cons | nc 10.9.3.253 2181 | 输出连接到Zookeeper的服务器信息，包括队列、数据接收量、数据发送量、sessionID、操作延时、最后的操作信息等等 |
| 3 | echo crst | nc 10.9.3.253 2181 | 重置当前的所有连接、会话等等 |
| 4 | echo dump | nc 10.9.3.253 2181 | 列出未经处理的会话和连接信息 |
| 5 | echo envi | nc 10.9.3.253 2181 | 列出zookeeper的版本信息、主机名称、Java版本、java_home、class_path、服务器名称、当前登陆用户名、目录等等； |
| 6 | echo ruok | nc 10.9.3.253 2181 | Are You Ok的缩写，测试服务器是否正在运行，如果在运行返回imok，否则返回空 |
| 7 | echo srst | nc 10.9.3.253 2181 | 重置Zookeeper的所有统计信息 |
| 8 | echo srvr | nc 10.9.3.253 2181 | 列出zookeeper的版本信息、数据接收/发送量、连接数、节点模式、Node数、最大/平均/最小延迟数 |
| 9 | echo stat | nc 10.9.3.253 2181 | 列出连接客户端列表、最大/平均/最小延迟数、数据接收/发送量、连接数、节点总数、模式 |
| 10 | echo wchs | nc 10.9.3.253 2181 | 列出watch的总数，连接数 |
| 11 | echo wchp | nc 10.9.3.253 2181 | 列出所有watch的路径及sessionID |
| 12 | echo mntr | nc 10.9.3.253 2181 | 列出集群的关键性能数据，包括zk的版本、最大/平均/最小延迟数、数据包接收/发送量、连接数、zk角色（Leader/Follower）、node数量、watch数量、临时节点数 |
1、echo conf | nc 10.9.3.253 2181
clientPort=2181 dataDir=/home/zookeeper/zookeeper-3.4.8/data/version-2 dataLogDir=/home/zookeeper/zookeeper-3.4.8/data/version-2 tickTime=2000 maxClientCnxns=60 minSessionTimeout=4000 maxSessionTimeout=40000 serverId=2 initLimit=10 syncLimit=5 electionAlg=3 electionPort=2223 quorumPort=2222 peerType=0
2、echo cons | nc 10.9.3.253 2181
/10.9.3.210:27080[1](queued=0,recved=21379,sent=21379,sid=0x26128063230003a,lop=PING,est=1517842262650,to=6000,lcxid=0x25,lzxid=0x500000e68,lresp=1517885010952,llat=0,minlat=0,avglat=1,maxlat=1832) /10.9.3.2:52081[0](queued=0,recved=1,sent=0) /10.9.3.253:53132[1](queued=0,recved=81690,sent=81690,sid=0x160e4217689000a,lop=PING,est=1516794950707,to=40000,lcxid=0x0,lzxid=0x500000e68,lresp=1517885010871,llat=0,minlat=0,avglat=0,maxlat=3667) /10.9.3.253:41271[1](queued=0,recved=89801,sent=89801,sid=0x260e42176ee0005,lop=GETC,est=1516868422715,to=40000,lcxid=0xd443,lzxid=0x500000e68,lresp=1517885009146,llat=0,minlat=0,avglat=1,maxlat=2328) /127.0.0.1:41248[1](queued=0,recved=21359,sent=21359,sid=0x260e42176ee0534,lop=PING,est=1517842262534,to=6000,lcxid=0xf0,lzxid=0x500000e68,lresp=1517885012461,llat=0,minlat=0,avglat=1,maxlat=1535) /10.9.3.253:53136[1](queued=0,recved=81692,sent=81692,sid=0x160e42176890009,lop=PING,est=1516794950841,to=40000,lcxid=0x5a,lzxid=0x500000e68,lresp=1517885009000,llat=0,minlat=0,avglat=1,maxlat=4846)
3、echo crst | nc 10.9.3.253 2181
Connection stats reset.
4、echo dunp | nc 10.9.3.253 2181
Sessions with Ephemerals (4): 0x160e42176890009: /hbase/rs/log1,16020,1515656342319 0x260e42176ee0005: /hbase/master 0x260e42176ee0534: /kafka/controller /kafka/brokers/ids/253 0x26128063230003a: /kafka/brokers/ids/210
5、echo envi |nc 10.9.3.253 2181
nvironment: zookeeper.version=3.4.8--1, built on 02/06/2016 03:18 GMT host.name=log1 java.version=1.8.0_102 java.vendor=Oracle Corporation java.home=/opt/jdk1.8.0_102/jre java.class.path=/home/zookeeper/zookeeper-3.4.8/bin/../build/classes:/home/zookeeper/zookeeper-3.4.8/bin/../build/lib/*.jar:/home/zookeeper/zookeeper-3.4.8/bin/../lib/slf4j-log4j12-1.6.1.jar:/home/zookeeper/zookeeper-3.4.8/bin/../lib/slf4j-api-1.6.1.jar:/home/zookeeper/zookeeper-3.4.8/bin/../lib/netty-3.7.0.Final.jar:/home/zookeeper/zookeeper-3.4.8/bin/../lib/log4j-1.2.16.jar:/home/zookeeper/zookeeper-3.4.8/bin/../lib/jline-0.9.94.jar:/home/zookeeper/zookeeper-3.4.8/bin/../zookeeper-3.4.8.jar:/home/zookeeper/zookeeper-3.4.8/bin/../src/java/lib/*.jar:/home/zookeeper/zookeeper-3.4.8/bin/../conf:.:/opt/jdk1.8.0_102/lib/dt.jar:/opt/jdk1.8.0_102/lib/tools.jar java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib java.io.tmpdir=/tmp java.compiler=<NA> os.name=Linux os.arch=amd64 os.version=2.6.32-431.el6.x86_64 user.name=zookeeper user.home=/home/zookeeper user.dir=/home/zookeeper/zookeeper-3.4.8/bin
6、echo ruok | nc 10.9.3.253 2181
imok
7、echo srsr | nc 10.9.3.253 2181
Server stats reset.
8、echo srvr | nc 10.9.3.253 2181
Zookeeper version: 3.4.8--1, built on 02/06/2016 03:18 GMT Latency min/avg/max: 0/0/1 Received: 160 Sent: 160 Connections: 6 Outstanding: 0 Zxid: 0x500000e68 Mode: leader Node count: 200
9、echo stat | nc 10.9.3.253 2181
Zookeeper version: 3.4.8--1, built on 02/06/2016 03:18 GMT Clients: /10.9.3.210:27080[1](queued=0,recved=688,sent=688) /10.9.3.253:53132[1](queued=0,recved=103,sent=103) /10.9.3.253:41271[1](queued=0,recved=123,sent=123) /127.0.0.1:41248[1](queued=0,recved=687,sent=687) /10.9.3.2:52642[0](queued=0,recved=1,sent=0) /10.9.3.253:53136[1](queued=0,recved=103,sent=103) Latency min/avg/max: 0/0/1 Received: 481 Sent: 481 Connections: 6 Outstanding: 0 Zxid: 0x500000e68 Mode: leader Node count: 200
10、echo wchs | nc 10.9.3.253 2181
4 connections watching 19 paths Total watches:24
11、echo wchp | nc 10.9.3.253 2181
/kafka/brokers/topics/asda 0x260e42176ee0534 /kafka/controller 0x260e42176ee0534 0x26128063230003a /kafka/isr_change_notification 0x260e42176ee0534 /kafka/brokers/topics 0x260e42176ee0534 /hbase/running 0x260e42176ee0005 0x160e42176890009 /kafka/brokers/topics/test 0x260e42176ee0534 /hbase/master 0x260e42176ee0005 0x160e42176890009 /kafka/config/changes 0x260e42176ee0534 0x26128063230003a /hbase/namespace 0x260e42176ee0005 /kafka/brokers/ids 0x260e42176ee0534 /hbase/namespace/hbase 0x260e42176ee0005 /kafka/admin/reassign_partitions 0x260e42176ee0534 /hbase/meta-region-server 0x160e42176890009 /hbase/rs/log1,16020,1515656342319 0x260e42176ee0005 0x160e42176890009 /hbase/namespace/default 0x260e42176ee0005 /hbase/normalizer 0x260e42176ee0005 /kafka/admin/delete_topics 0x260e42176ee0534 /hbase/balancer 0x260e42176ee0005 /kafka/admin/preferred_replica_election 0x260e42176ee0534
12、echo mntr | nc 10.9.3.253 2181
zk_version 3.4.8--1, built on 02/06/2016 03:18 GMT zk_avg_latency 0 zk_max_latency 1 zk_min_latency 0 zk_packets_received 2876 zk_packets_sent 2876 zk_num_alive_connections 6 zk_outstanding_requests 0 zk_server_state leader zk_znode_count 200 zk_watch_count 41 zk_ephemerals_count 5 zk_approximate_data_size 35502 zk_open_file_descriptor_count 37 zk_max_file_descriptor_count 65536 zk_followers 1 zk_synced_followers 1 zk_pending_syncs 0
