中间件 ZK分布式专题与Dubbo微服务入门 4-16 zk四字命令 上

0　　　　课程地址

https://coding.imooc.com/lesson/201.html#mid=12712

 

1　　　　重点关注

1.1　　　　执行前准备

zk四字命令 Four Letter Words
zk可以通过安自身提供的简写命令来和服务器进行交互

 

• 安装nc

需要使用到 nc命令，安装: yum install nc

 

• 四字命令官方文档

百度zookeeper->Documention->版本->左侧Admin & Ops->Administrator's Guide->搜索four Letter
可以看到4字命令

 

• 四字命令格式

echo [command] | nc [ip] [port]

 

 

1.2　　　　常见四字命令

• [stat] 查看zk的状态信息，以及是否mode,集群或单例

echo stat | nc localhost 2181

[root@localhost ~]# echo stat | nc localhost 2181
Zookeeper version: 3.4.11-37e277162d567b55a07d1755f0b31c32e93c01a0, built on 11/01/2017 18:06 GMT
Clients:
 /0:0:0:0:0:0:0:1:44292[0](queued=0,recved=1,sent=0)
 /127.0.0.1:53684[1](queued=0,recved=124,sent=124)

Latency min/avg/max: 0/0/15
Received: 133
Sent: 132
Connections: 2
Outstanding: 0
Zxid: 0x62
Mode: standalone　　　　　　--说明单例模式，不是集群
Node count: 14

 

 

• [ruok] 查看当前zkserver是否启动，返回 imok或Ncat

echo ruok | nc localhost 2181

imok 启动状态，ncat没有猫，未启动

 

• [dump] 列出未经处理的会话和临时节点

echo dump | nc localhost 2181

[root@localhost ~]# echo dump | nc localhost 2181
SessionTracker dump:
Session Sets (3):
0 expire at Thu Jan 08 09:37:50 CST 1970:
0 expire at Thu Jan 08 09:38:00 CST 1970:
1 expire at Thu Jan 08 09:38:10 CST 1970:　　　　--1个开启的会话
        0x100244d3cf10000
ephemeral nodes dump:
Sessions with Ephemerals (1):　　　　　　　　　　　--1个临时节点
0x100244d3cf10000:
        /names/temp-dump

 

 

• [conf] 查看zk服务端配置

echo conf | nc localhost 2181

[root@localhost ~]# echo conf | nc localhost 2181
clientPort=2181                                                                 --端口
dataDir=/usr/local/zookeeper/dataDir/version-2                                  --数据路径
dataLogDir=/usr/local/zookeeper/dataLogDir/version-2                            --日志路径
tickTime=2000                                                                   --执行单元 2s
maxClientCnxns=60
minSessionTimeout=4000
maxSessionTimeout=40000
serverId=0
[root@localhost ~]# 

 

 

• [cons]查看zk连接到服务器的客户端信息

echo cons | nc localhost 2181

 [root@localhost ~]# echo cons | nc localhost 2181
 /0:0:0:0:0:0:0:1:44288[0](queued=0,recved=1,sent=0)
 /127.0.0.1:53684[1](queued=0,recved=56,sent=56,sid=0x100244d3cf10000,lop=PING,est=1708902855675,to=30000,lcxid=0x3,lzxid=0x62,lresp=609658541,llat=0,minlat=0,avglat=0,maxlat=15)
 

 

 

• [envi]环境变量

echo envi | nc localhost 2181

[root@localhost ~]# echo envi | nc localhost 2181
Environment:
zookeeper.version=3.4.11-37e277162d567b55a07d1755f0b31c32e93c01a0, built on 11/01/2017 18:06 GMT
host.name=localhost
java.version=1.8.0_202
java.vendor=Oracle Corporation
java.home=/usr/jdk8/jre
java.class.path=/usr/local/zookeeper/bin/../build/classes:/usr/local/zookeeper/bin/../build/lib/*.jar:/usr/local/zookeeper/bin/../lib/slf4j-log4j12-1.6.1.jar:/usr/local/zookeeper/bin/../lib/slf4j-api-1.6.1.jar:/usr/local/zookeeper/bin/../lib/netty-3.10.5.Final.jar:/usr/local/zookeeper/bin/../lib/log4j-1.2.16.jar:/usr/local/zookeeper/bin/../lib/jline-0.9.94.jar:/usr/local/zookeeper/bin/../lib/audience-annotations-0.5.0.jar:/usr/local/zookeeper/bin/../zookeeper-3.4.11.jar:/usr/local/zookeeper/bin/../src/java/lib/*.jar:/usr/local/zookeeper/bin/../conf:.:%JAVA_HOME%/lib/dt.jar:%JAVA_HOME%/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=3.10.0-1160.el7.x86_64
user.name=root
user.home=/root
user.dir=/usr/local/zookeeper/bin
[root@localhost ~]# 

 

 

 

2　　　　课程内容

2.1　　　　创建临时节点

create -e /names/temp-dump 111

 

 

3　　　　Coding