zookeeper
文章目录
- 前言
- 一、为什么需要zookeeper？
- 二、zookeeper的特点
- 三 zookeeper架构图
- 四 zookeeper作用
- 五 zookeeper安装和配置
-
- 1 安装
- 2 配置
- 六 zookeeper的zndoe节点
- 七 命令
-
- 1 常用命令
- 2 高级命令
- 3 Watcher机制
- 八 ACL权限控制（五种）
- 九 代码实操
-
- 0 pom依赖 引入 参考结构
- 1 简单的链接
- 2 对zk的增删改查
- 3 处理watcher事件（与2 的不同主要是wather的改变）
- 4 使用apache curator操作zk
前言
zookeeper入门
一、为什么需要zookeeper？
雅虎的很多大型系统软件都由动物（dog，cat）命名
而zookeeper（动物园）相当于这些软件系统的分布式协调框架
二、zookeeper的特点
三 zookeeper架构图
Leader死后很快能进行重新选举
四 zookeeper作用
五 zookeeper安装和配置
1 安装
https://downloads.apache.org/zookeeper/zookeeper-3.6.3/
进入网址选择复制连接
然后进入Linux下
wget + 链接
下载好后输入如下命令进行解压
tar zxvf apache-zookeeper-3.6.3-bin.tar.gz
2 配置
首先进入目录下复制一份配置文件
[root@iZuf6bsml3xp6lqbtvsilzZ apache-zookeeper-3.6.3-bin]# cp conf/zoo_sample.cfg conf/zoo.cfg
[root@iZuf6bsml3xp6lqbtvsilzZ apache-zookeeper-3.6.3-bin]# cd conf
[root@iZuf6bsml3xp6lqbtvsilzZ conf]# ls
configuration.xsl log4j.properties zoo.cfg zoo_sample.cfg
[root@iZuf6bsml3xp6lqbtvsilzZ conf]#
简单观察配置文件
停止命令 启动命令stop换为start
六 zookeeper的zndoe节点
七 命令
1 常用命令
启动服务端
[root@iZuf6bsml3xp6lqbtvsilzZ apache-zookeeper-3.6.3-bin]# ./bin/zkServer.sh start
启动客户端
[root@iZuf6bsml3xp6lqbtvsilzZ apache-zookeeper-3.6.3-bin]# ./bin/zkCli.sh -server 127.0.0.1:2181
简单的zode 增删改查操作
[zk: 127.0.0.1:2181(CONNECTED) 2] ls -R /
/
/zookeeper
/zookeeper/config
/zookeeper/quota
[zk: 127.0.0.1:2181(CONNECTED) 3] create /java1
Created /java1
[zk: 127.0.0.1:2181(CONNECTED) 4] set /java1 data1
[zk: 127.0.0.1:2181(CONNECTED) 5] get /java1
data1
[zk: 127.0.0.1:2181(CONNECTED) 6] ls -R /
/
/java1
/zookeeper
/zookeeper/config
/zookeeper/quota
[zk: 127.0.0.1:2181(CONNECTED) 7]
2 高级命令
[zk: 127.0.0.1:2181(CONNECTED) 12] stat /java1
cZxid = 0x2
ctime = Tue Apr 19 11:05:07 CST 2022
mZxid = 0x5
mtime = Tue Apr 19 11:18:39 CST 2022
pZxid = 0x2
cversion = 0
dataVersion = 2
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 3
numChildren = 0
版本号操作set更改
[zk: 127.0.0.1:2181(CONNECTED) 13] set /java1 qqqq -v2
[zk: 127.0.0.1:2181(CONNECTED) 14] set /java1 qqqqq -v2
version No is not valid : /java1
创建临时节点
[zk: 127.0.0.1:2181(CONNECTED) 15] create /java1/test1 -e
Created /java1/test1
[zk: 127.0.0.1:2181(CONNECTED) 16] stat /java1/test1
cZxid = 0x8
ctime = Tue Apr 19 11:21:22 CST 2022
mZxid = 0x8
mtime = Tue Apr 19 11:21:22 CST 2022
pZxid = 0x8
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x100690cbce20000
dataLength = 0
numChildren = 0
//创建这个节点同时为临时节点和顺序节点
[zk: 127.0.0.1:2181(CONNECTED) 17] create /java1/test1 -e -s
Created /java1/test10000000001
[zk: 127.0.0.1:2181(CONNECTED) 18]
3 Watcher机制
八 ACL权限控制（五种）
九 代码实操
0 pom依赖 引入 参考结构
org.apache.zookeeper
zookeeper
3.6.0
org.apache.curator
curator-framework
2.12.0
org.apache.curator
curator-recipes
2.12.0
1 简单的链接
package com.imooc.zkjavaapi;
/**
* 描述： ZK常量
*/
public class ZkConstant {
public static final String ZK_HOST = "127.0.0.1:2181";
public static final Integer CONNECT_TIMEOUT = 3000;
public static final String PATH1 = "/imooc-my-first-node";
}
package com.imooc.zkjavaapi.watcher;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.KeeperState;
/**
* 描述： 连接Watcher
*/
public class ConnectWatcher implements Watcher {
@Override
public void process(WatchedEvent event) {
System.out.println("ConnectWatcher的process被调用了");
if (event.getState()== KeeperState.SyncConnected) {
System.out.println("连接成功");
}
if (event.getState()== KeeperState.Closed) {
System.out.println("连接关闭");
}
}
}
package com.imooc.zkjavaapi;
import com.imooc.zkjavaapi.watcher.ConnectWatcher;
import java.io.IOException;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooKeeper.States;
/**
* 描述： 连接到ZK
*/
public class FirstConnect {
public static void main(String[] args) throws IOException, InterruptedException {
//创建watcher对象
ConnectWatcher connectWatcher = new ConnectWatcher();
//new zk对象
ZooKeeper zk = new ZooKeeper(ZkConstant.ZK_HOST, ZkConstant.CONNECT_TIMEOUT, connectWatcher);
System.out.println("客户端开始连接ZK服务器");
States state = zk.getState();
System.out.println(state);
Thread.sleep(2000);
state = zk.getState();
System.out.println(state);
Thread.sleep(2000);
zk.close();
}
}
2 对zk的增删改查
package com.imooc.zkjavaapi;
/**
* 描述： ZK常量
*/
public class ZkConstant {
public static final String ZK_HOST = "127.0.0.1:2181";
public static final Integer CONNECT_TIMEOUT = 3000;
public static final String PATH1 = "/imooc-my-first-node";
}
package com.imooc.zkjavaapi.watcher;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.KeeperState;
/**
* 描述： 连接Watcher
*/
public class ConnectWatcher implements Watcher {
@Override
public void process(WatchedEvent event) {
System.out.println("ConnectWatcher的process被调用了");
if (event.getState()== KeeperState.SyncConnected) {
System.out.println("连接成功");
}
if (event.getState()== KeeperState.Closed) {
System.out.println("连接关闭");
}
}
}
package com.imooc.zkjavaapi;
import com.imooc.zkjavaapi.watcher.ConnectWatcher;
import java.io.IOException;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooKeeper.States;
/**
* 描述： 对节点的增删改查
*/
public class ZkCRUD {
public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
ConnectWatcher connectWatcher = new ConnectWatcher();
ZooKeeper zk = new ZooKeeper(ZkConstant.ZK_HOST, ZkConstant.CONNECT_TIMEOUT, connectWatcher);
System.out.println("客户端开始连接ZK服务器");
States state = zk.getState();
System.out.println(state);
Thread.sleep(2000);
state = zk.getState();
System.out.println(state);
Thread.sleep(2000);
//对节点进行增删改查
zk.create(ZkConstant.PATH1, "imooc1".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
Thread.sleep(2000);
byte[] data = null;
data = zk.getData(ZkConstant.PATH1, null, null);
System.out.println(new String(data));
Thread.sleep(2000);
zk.setData(ZkConstant.PATH1, "imooc2".getBytes(), -1);
Thread.sleep(2000);
data = zk.getData(ZkConstant.PATH1, null, null);
System.out.println(new String(data));
zk.delete(ZkConstant.PATH1, -1);
zk.close();
}
}
3 处理watcher事件（与2 的不同主要是wather的改变）
1 watcher
package com.imooc.zkjavaapi.watcher;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.Watcher.Event.KeeperState;
public class DataChangedWatcher implements Watcher {
@Override
public void process(WatchedEvent event) {
System.out.println("DataChangedWatcher的process被调用了");
if (event.getType()== EventType.NodeDataChanged) {
System.out.println("数据被改变");
}
if (event.getType()== EventType.NodeDeleted) {
System.out.println("节点已删除");
}
}
}
2 主要代码
package com.imooc.zkjavaapi;
import com.imooc.zkjavaapi.watcher.ConnectWatcher;
import com.imooc.zkjavaapi.watcher.DataChangedWatcher;
import java.io.IOException;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooKeeper.States;
/**
* 描述： ZK节点改变、删除事件的监听
*/
public class ZkWatcher {
public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
DataChangedWatcher dataChangedWatcher = new DataChangedWatcher();
ZooKeeper zk = new ZooKeeper(ZkConstant.ZK_HOST, ZkConstant.CONNECT_TIMEOUT, dataChangedWatcher);
System.out.println("客户端开始连接ZK服务器");
States state = zk.getState();
System.out.println(state);
Thread.sleep(2000);
state = zk.getState();
System.out.println(state);
Thread.sleep(2000);
zk.create(ZkConstant.PATH1, "imooc1".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
Thread.sleep(2000);
byte[] data = null;
//watcher设置为true，代表可以监听对应的事件
data = zk.getData(ZkConstant.PATH1, true, null);
System.out.println(new String(data));
Thread.sleep(2000);
zk.setData(ZkConstant.PATH1, "imooc2".getBytes(), -1);
Thread.sleep(2000);
data = zk.getData(ZkConstant.PATH1, true, null);
System.out.println(new String(data));
zk.delete(ZkConstant.PATH1, -1);
zk.close();
}
}
需要的一些常量
package com.imooc.zkjavaapi;
/**
* 描述： ZK常量
*/
public class ZkConstant {
public static final String ZK_HOST = "127.0.0.1:2181";
public static final Integer CONNECT_TIMEOUT = 3000;
public static final String PATH1 = "/imooc-my-first-node";
}
4 使用apache curator操作zk
创传统的java api写法复杂
功能不强
org.apache.curator
curator-framework
2.12.0
org.apache.curator
curator-recipes
2.12.0
代码实现
package com.imooc.curator;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.curator.framework.recipes.cache.ChildData;
import org.apache.curator.framework.recipes.cache.NodeCache;
import org.apache.curator.framework.recipes.cache.NodeCacheListener;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher.Event.EventType;
/**
* 描述： 用Curator来操作ZK
*/
public class CuratorTests {
public static void main(String[] args) throws Exception {
//链接字符串
String connectString = "127.0.0.1:2181";
//路径
String path = "/curator1";
//设置重连操作
ExponentialBackoffRetry retry = new ExponentialBackoffRetry(1000, 10);
//使用 1链接字符串 2设置重连操作 创建连接对象client
CuratorFramework client = CuratorFrameworkFactory.newClient(connectString, retry);
//开启连接对象
client.start();
client.getCuratorListenable().addListener((CuratorFramework c, CuratorEvent event) -> {
switch (event.getType()) {
case WATCHED:
WatchedEvent watchedEvent = event.getWatchedEvent();
if (watchedEvent.getType() == EventType.NodeDataChanged) {
System.out.println(new String(c.getData().forPath(path)));
System.out.println("触发事件");
}
}
});
String data = "test";
String data2 = "test2";
//用连接对象创建节点 节点类型为临时节点（withMode）forpath是节点路径 Data是设置该节点的数据
client.create().withMode(CreateMode.EPHEMERAL).forPath(path, data.getBytes());
//根据Path获得节点数据 并且使用watched开启监听
byte[] bytes = client.getData().watched().forPath(path);
System.out.println(new String(bytes));
//根据Path重新设置数据
client.setData().forPath(path, data2.getBytes());
Thread.sleep(2000);
client.delete().forPath(path);
Thread.sleep(2000);
//永久监听
String pathNew = "/curatorNew";
client.create().withMode(CreateMode.EPHEMERAL).forPath(pathNew, data.getBytes());
NodeCache nodeCache = new NodeCache(client, pathNew);
nodeCache.start();
nodeCache.getListenable().addListener(new NodeCacheListener() {
@Override
public void nodeChanged() throws Exception {
ChildData currentData = nodeCache.getCurrentData();
if (currentData != null) {
System.out.println("触发了永久监听的回调，当前值为：" + new String(currentData.getData()));
}
}
});
client.setData().forPath(pathNew, data2.getBytes());
Thread.sleep(2000);
client.setData().forPath(pathNew, data2.getBytes());
Thread.sleep(2000);
client.setData().forPath(pathNew, data2.getBytes());
Thread.sleep(2000);
client.delete().forPath(pathNew);
}
}