zookeeper环境搭建学习

zookeeper介绍

zookeeper=文件系统+通知机制

1、Zookeeper:一个领导者(Leader)，多个跟随者(Flower)组成的集群。
2、集群中只要有半数以上节点存活，Zookeeper集群就能正常服务。
3、全局数据一致， 每个server保存一份相同的数据副本，client无论连接到哪个server，数据都是一致的。
4、更新请求顺序进行，来自同一client的更新请求按其发送顺序依次执行。
5、数据更新原子性，一次数据更新要么成功，要么失败。
6、实时性，在一定时间范围内，client能读到最新的数据。

数据结构：
树形结构和unix文件系统类似，整体上可以看做一棵树，每个节点称作一个Znode,每一个Znode默认能够存储1MB的数据，每个Znode都可以通过其路径唯一标识。

本地环境,一共3台服务器

192.168.150.101

192.168.150.102

192.168.150.103

安装方法

先装java 1.8 jdk （略过）
官网下载地址：
https://zookeeper.apache.org/releases.html#download

tar xvf apache-zookeeper-3.5.8-bin.tar.gz -C /usr/local
cd /usr/local
mv apache-zookeeper-3.5.8-bin/ zookeeper

cd /usr/local/zookeeper/conf
mv zoo_sample.cfg zoo.cfg
mkdir /usr/local/zookeeper/zkData
vi zoo.cfg

修改数据文件保存目录
dataDir=/usr/local/zookeeper/zkData

启动zookeeper

[root@host101 zookeeper]# bin/zkServer.sh start
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED

[root@host101 zookeeper]# jps
11809 Jps
11759 QuorumPeerMain   ---多了这个进程

查看状态

[root@host101 zookeeper]# bin/zkServer.sh status
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Client port found: 2181. Client address: localhost.
Mode: standalone     ---单机模式

启动客户端

[root@host101 zookeeper]# bin/zkCli.sh 
/usr/bin/java
Connecting to localhost:2181
2020-11-26 23:30:33,401 [myid:] - INFO  [main:Environment@109] - Client environment:zookeeper.version=3.5.8-f439ca583e70862c3068a1f2a7d4d068eec33315, built on 05/04/2020 15:07 GMT
2020-11-26 23:30:33,407 [myid:] - INFO  [main:Environment@109] - Client environment:host.name=host101
2020-11-26 23:30:33,407 [myid:] - INFO  [main:Environment@109] - Client environment:java.version=1.8.0_181
2020-11-26 23:30:33,421 [myid:] - INFO  [main:Environment@109] - Client environment:java.vendor=Oracle Corporation
2020-11-26 23:30:33,421 [myid:] - INFO  [main:Environment@109] - Client environment:java.home=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.181-7.b13.el7.x86_64/jre
2020-11-26 23:30:33,421 [myid:] - INFO  [main:Environment@109] - Client environment:java.class.path=/usr/local/zookeeper/bin/../zookeeper-server/target/classes:/usr/local/zookeeper/bin/../build/classes:/usr/local/zookeeper/bin/../zookeeper-server/target/lib/*.jar:/usr/local/zookeeper/bin/../build/lib/*.jar:/usr/local/zookeeper/bin/../lib/zookeeper-jute-3.5.8.jar:/usr/local/zookeeper/bin/../lib/zookeeper-3.5.8.jar:/usr/local/zookeeper/bin/../lib/slf4j-log4j12-1.7.25.jar:/usr/local/zookeeper/bin/../lib/slf4j-api-1.7.25.jar:/usr/local/zookeeper/bin/../lib/netty-transport-native-unix-common-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/netty-transport-native-epoll-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/netty-transport-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/netty-resolver-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/netty-handler-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/netty-common-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/netty-codec-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/netty-buffer-4.1.48.Final.jar:/usr/local/zookeeper/bin/../lib/log4j-1.2.17.jar:/usr/local/zookeeper/bin/../lib/json-simple-1.1.1.jar:/usr/local/zookeeper/bin/../lib/jline-2.11.jar:/usr/local/zookeeper/bin/../lib/jetty-util-9.4.24.v20191120.jar:/usr/local/zookeeper/bin/../lib/jetty-servlet-9.4.24.v20191120.jar:/usr/local/zookeeper/bin/../lib/jetty-server-9.4.24.v20191120.jar:/usr/local/zookeeper/bin/../lib/jetty-security-9.4.24.v20191120.jar:/usr/local/zookeeper/bin/../lib/jetty-io-9.4.24.v20191120.jar:/usr/local/zookeeper/bin/../lib/jetty-http-9.4.24.v20191120.jar:/usr/local/zookeeper/bin/../lib/javax.servlet-api-3.1.0.jar:/usr/local/zookeeper/bin/../lib/jackson-databind-2.10.3.jar:/usr/local/zookeeper/bin/../lib/jackson-core-2.10.3.jar:/usr/local/zookeeper/bin/../lib/jackson-annotations-2.10.3.jar:/usr/local/zookeeper/bin/../lib/commons-cli-1.2.jar:/usr/local/zookeeper/bin/../lib/audience-annotations-0.5.0.jar:/usr/local/zookeeper/bin/../zookeeper-*.jar:/usr/local/zookeeper/bin/../zookeeper-server/src/main/resources/lib/*.jar:/usr/local/zookeeper/bin/../conf:
2020-11-26 23:30:33,422 [myid:] - INFO  [main:Environment@109] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
2020-11-26 23:30:33,422 [myid:] - INFO  [main:Environment@109] - Client environment:java.io.tmpdir=/tmp
2020-11-26 23:30:33,422 [myid:] - INFO  [main:Environment@109] - Client environment:java.compiler=<NA>
2020-11-26 23:30:33,422 [myid:] - INFO  [main:Environment@109] - Client environment:os.name=Linux
2020-11-26 23:30:33,422 [myid:] - INFO  [main:Environment@109] - Client environment:os.arch=amd64
2020-11-26 23:30:33,422 [myid:] - INFO  [main:Environment@109] - Client environment:os.version=3.10.0-957.el7.x86_64
2020-11-26 23:30:33,423 [myid:] - INFO  [main:Environment@109] - Client environment:user.name=root
2020-11-26 23:30:33,423 [myid:] - INFO  [main:Environment@109] - Client environment:user.home=/root
2020-11-26 23:30:33,423 [myid:] - INFO  [main:Environment@109] - Client environment:user.dir=/usr/local/zookeeper
2020-11-26 23:30:33,423 [myid:] - INFO  [main:Environment@109] - Client environment:os.memory.free=24MB
2020-11-26 23:30:33,436 [myid:] - INFO  [main:Environment@109] - Client environment:os.memory.max=247MB
2020-11-26 23:30:33,436 [myid:] - INFO  [main:Environment@109] - Client environment:os.memory.total=29MB
2020-11-26 23:30:33,445 [myid:] - INFO  [main:ZooKeeper@868] - Initiating client connection, connectString=localhost:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@7e774085
2020-11-26 23:30:33,474 [myid:] - INFO  [main:X509Util@79] - Setting -D jdk.tls.rejectClientInitiatedRenegotiation=true to disable client-initiated TLS renegotiation
2020-11-26 23:30:33,515 [myid:] - INFO  [main:ClientCnxnSocket@237] - jute.maxbuffer value is 4194304 Bytes
2020-11-26 23:30:33,541 [myid:] - INFO  [main:ClientCnxn@1653] - zookeeper.request.timeout value is 0. feature enabled=
Welcome to ZooKeeper!
2020-11-26 23:30:33,602 [myid:localhost:2181] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@1112] - Opening socket connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2020-11-26 23:30:33,868 [myid:localhost:2181] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@959] - Socket connection established, initiating session, client: /127.0.0.1:45378, server: localhost/127.0.0.1:2181
2020-11-26 23:30:33,930 [myid:localhost:2181] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@1394] - Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x100002ff2310000, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null
[zk: localhost:2181(CONNECTED) 0] 

查看命令

[zk: localhost:2181(CONNECTED) 0] ls /
[zookeeper]
[zk: localhost:2181(CONNECTED) 1] 

退出quit

[zk: localhost:2181(CONNECTED) 1] quit

WATCHER::

WatchedEvent state:Closed type:None path:null
2020-11-26 23:31:44,737 [myid:] - INFO  [main:ZooKeeper@1422] - Session: 0x100002ff2310000 closed
2020-11-26 23:31:44,738 [myid:] - INFO  [main-EventThread:ClientCnxn$EventThread@524] - EventThread shut down for session: 0x100002ff2310000
[root@host101 zookeeper]# 

停止zookeeper服务

[root@host101 zookeeper]# bin/zkServer.sh stop
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Stopping zookeeper ... STOPPED
[root@host101 zookeeper]# jps
12289 Jps
[root@host101 zookeeper]# 

配置文件说明

tickTime=2000
心跳时间
initLimit=10
集群启动时，最大延迟时间：initLimit*tickTime，
syncLimit=5
集群启动后，最大延迟时间：syncLimit*tickTime
dataDir=/usr/local/zookeeper/zkData
数据文件目录
clientPort=2181
端口号

节点类型：

持久型(Persistent)：客户端和服务器连接断开后，创建的节点不删除。
1、持久化目录节点，客户端和zookeeper断开连接后，该节点依然存在。
2、持久化顺序编号目录节点，客户端和zookeeper断开连接后，该节点依然存在，只是zookeeper给该节点名称进行顺序编号。
说明，创建znode时设置顺序标识，znode名称后会附加一个值，顺序号是一个单调递增的计数器，由父节点维护。

短暂(Ephemeral)：客户端和服务器连接断开后，创建的节点自己删除。
3、临时目录节点，客户端和zookeeper连接断开后，该节点被删除。
4、临时顺序编号目录节点，客户端和zookeeper断开连接后，该节点被删除，只是zookeeper给该节点名称进行顺序编号。

搭建集群

在102 103服务器分别参考之前的安装方法进行安装。
cd /usr/local/zookeeper/zkData
touch myid

vim myid
三台服务器分为写自己的ip地址后三位（101、102、103）

修改三台服务器zoo.cfg配置
server.101=192.168.150.101:2888:3888
server.102=192.168.150.102:2888:3888
server.103=192.168.150.103:2888:3888

参数格式：
server.A=B:C:D
A是一个数字，表示这是第几个服务器。
集群模式下配置一个文件myid，这个文件在dataDir目录下，这个文件里面有一个数据就是A的值，Zookeeper启动时读取此文件，拿到里面的数据与zoo.cfg里面的配置信息比较从而判断到底是哪个server。
B是这个服务器的ip地址；
C是这个服务器与集群中的Leader服务器交换信息的端口；
D是万一集群中的Leader服务器挂了，需要一个端口来重新进行选举，选出一个新的Leader，而这个端口就是用来执行选举时服务器相互通信的端口。

启动三台服务

[root@host103 zookeeper]# bin/zkServer.sh start
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
[root@host103 zookeeper]# 

查看状态

[root@host103 zookeeper]# bin/zkServer.sh status
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/bin/../conf/zoo.cfg
Client port found: 2181. Client address: localhost.
Mode: leader
[root@host103 zookeeper]# 

客户端命令

help:显示所有操作命令
ls path [watch]:使用ls命令查看当前znode中所包含的内容
ls2 path [watch]:查看当前节点数据并能看到更新次数等数据
create:普通创建
-s 含有序列
-e 临时（重启或超时消失）
get path [watch]:获得节点的值
set:设置节点的具体值
stat:查看节点状态
delete:删除节点
rmr:递归删除节点

1、启动客户端

bin/zkCli.sh

2、显示所有操作命令 help

[zk: localhost:2181(CONNECTED) 5] help
ZooKeeper -server host:port cmd args
    addauth scheme auth
    close 
    config [-c] [-w] [-s]
    connect host:port
    create [-s] [-e] [-c] [-t ttl] path [data] [acl]
    delete [-v version] path
    deleteall path
    delquota [-n|-b] path
    get [-s] [-w] path
    getAcl [-s] path
    history 
    listquota path
    ls [-s] [-w] [-R] path
    ls2 path [watch]
    printwatches on|off
    quit 
    reconfig [-s] [-v version] [[-file path] | [-members serverID=host:port1:port2;port3[,...]*]] | [-add serverId=host:port1:port2;port3[,...]]* [-remove serverId[,...]*]
    redo cmdno
    removewatches path [-c|-d|-a] [-l]
    rmr path
    set [-s] [-v version] path data
    setAcl [-s] [-v version] [-R] path acl
    setquota -n|-b val path
    stat [-w] path
    sync path
Command not found: Command not found help
[zk: localhost:2181(CONNECTED) 6] 

3、查看当前znode中所包含的内容 ls /

[zk: localhost:2181(CONNECTED) 6] ls /
[zookeeper]
[zk: localhost:2181(CONNECTED) 7] 

4、查看当节点详细的数据 ls2 /

[zk: localhost:2181(CONNECTED) 7] ls2 /
'ls2' has been deprecated. Please use 'ls [-s] path' instead.
[zookeeper]
cZxid = 0x0
ctime = Thu Jan 01 08:00:00 CST 1970
mZxid = 0x0
mtime = Thu Jan 01 08:00:00 CST 1970
pZxid = 0x0
cversion = -1
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 0
numChildren = 1
[zk: localhost:2181(CONNECTED) 8] 

5、创建两个数据节点

[zk: localhost:2181(CONNECTED) 8] create sanguo "jinlian"
Path must start with / character
[zk: localhost:2181(CONNECTED) 9] create /sanguo "jinlian"
Created /sanguo
[zk: localhost:2181(CONNECTED) 10] ls /
[sanguo, zookeeper]
[zk: localhost:2181(CONNECTED) 11] create /sanguo/shuguo "liubei"
Created /sanguo/shuguo
[zk: localhost:2181(CONNECTED) 12] ls /sanguo
[shuguo]

6、获取节点的值

[zk: localhost:2181(CONNECTED) 13] get /sanguo/shuguo
liubei

7、创建短暂节点

[zk: localhost:2181(CONNECTED) 14] create -e /sanguo/wuguo "zhouyu"
Created /sanguo/wuguo
[zk: localhost:2181(CONNECTED) 15] ls /sanguo
[shuguo, wuguo]

quit退出再进入，已经没有wuguo节点了
[zk: localhost:2181(CONNECTED) 0] ls /sanguo
[shuguo]

8、创建带序号的节点

[zk: localhost:2181(CONNECTED) 1] create -s /sanguo/weiguo "caocao"
Created /sanguo/weiguo0000000002
[zk: localhost:2181(CONNECTED) 2] ls /sanguo
[shuguo, weiguo0000000002]
[zk: localhost:2181(CONNECTED) 3] create -s /sanguo/weiguo "caocao"
Created /sanguo/weiguo0000000003
[zk: localhost:2181(CONNECTED) 4] create -s /sanguo/weiguo "caocao"
Created /sanguo/weiguo0000000004
[zk: localhost:2181(CONNECTED) 5] ls /sanguo
[shuguo, weiguo0000000002, weiguo0000000003, weiguo0000000004]

9、修改节点的值

[zk: localhost:2181(CONNECTED) 6] set /sanguo/shuguo "diaochan"
[zk: localhost:2181(CONNECTED) 8] get /sanguo/shuguo
diaochan

10、节点的值变化监听

10.1在101上注册监控/sanguo节点数据变化。注册一次，仅有效一次
[zk: localhost:2181(CONNECTED) 3] get /sanguo watch
'get path [watch]' has been deprecated. Please use 'get [-s] [-w] path' instead.
jinlian

103上去修改/sanguo的值
[zk: localhost:2181(CONNECTED) 9] set /sanguo "jingjing"

101上会提示如下
[zk: localhost:2181(CONNECTED) 3] get /sanguo watch
'get path [watch]' has been deprecated. Please use 'get [-s] [-w] path' instead.
jinlian
[zk: localhost:2181(CONNECTED) 4] 
WATCHER::

WatchedEvent state:SyncConnected type:NodeDataChanged path:/sanguo

11、节点的子节点变化监听（路径变化）

在101上注册监控/sanguo节点的子节点变化
101上执行
[zk: localhost:2181(CONNECTED) 4] ls /sanguo watch
'ls path [watch]' has been deprecated. Please use 'ls [-w] path' instead.
[shuguo, weiguo0000000002, weiguo0000000003, weiguo0000000004]

103上执行
[zk: localhost:2181(CONNECTED) 10] create /sanguo/banzhang "banzhang"
Created /sanguo/banzhang


101返回如下
[zk: localhost:2181(CONNECTED) 4] ls /sanguo watch
'ls path [watch]' has been deprecated. Please use 'ls [-w] path' instead.
[shuguo, weiguo0000000002, weiguo0000000003, weiguo0000000004]
[zk: localhost:2181(CONNECTED) 5] 
WATCHER::

WatchedEvent state:SyncConnected type:NodeChildrenChanged path:/sanguo

12、删除节点

[zk: localhost:2181(CONNECTED) 6] ls /sanguo
[shuguo, weiguo0000000002, weiguo0000000003, weiguo0000000004]
[zk: localhost:2181(CONNECTED) 7] 

13、递归删除节点

[zk: localhost:2181(CONNECTED) 7] rmr /sanguo
The command 'rmr' has been deprecated. Please use 'deleteall' instead.
[zk: localhost:2181(CONNECTED) 8] ls /sanguo
Node does not exist: /sanguo
[zk: localhost:2181(CONNECTED) 9]