三种连接ZooKeeper的方式

谁借莪１个温暖的怀抱￠ 2022-04-22 04:02 1127阅读 0赞

1. 使用客户端命令连接Zookeeper  
连接Server   
使用命令./zkCli.sh -server 127.0.0.1:2181

连接成功后返回如下信息：

Connecting to 127.0.0.1:2181  
2018-06-20 00:13:40,884 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:zookeeper.version=3.4.12-e5259e437540f349646870ea94dc2658c4e44b3b, built on 03/27/2018 03:55 GMT  
2018-06-20 00:13:40,887 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:host.name=localhost  
2018-06-20 00:13:40,887 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:java.version=1.8.0\_171  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:java.vendor=Oracle Corporation  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:java.home=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-7.b10.el7.x86\_64/jre  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:java.class.path=/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../build/classes:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../build/lib/\*.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../lib/slf4j-log4j12-1.7.25.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../lib/slf4j-api-1.7.25.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../lib/netty-3.10.6.Final.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../lib/log4j-1.2.17.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../lib/jline-0.9.94.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../lib/audience-annotations-0.5.0.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../zookeeper-3.4.12.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../src/java/lib/\*.jar:/usr/local/services/zookeeper/zookeeper-3.4.12/bin/../conf:  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:java.io.tmpdir=/tmp  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:java.compiler=<NA>  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:os.name=Linux  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:os.arch=amd64  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:os.version=3.10.0-862.2.3.el7.x86\_64  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:user.name=root  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:user.home=/root  
2018-06-20 00:13:40,889 \[myid:\] - INFO  \[main:Environment@100\] - Client environment:user.dir=/usr/local/services/zookeeper/zookeeper-3.4.12/bin  
2018-06-20 00:13:40,890 \[myid:\] - INFO  \[main:ZooKeeper@441\] - Initiating client connection, connectString=127.0.0.1:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@446cdf90  
Welcome to ZooKeeper!  
2018-06-20 00:13:40,928 \[myid:\] - INFO  \[main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1028\] - Opening socket connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)  
JLine support is enabled  
2018-06-20 00:13:40,989 \[myid:\] - INFO  \[main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@878\] - Socket connection established to 127.0.0.1/127.0.0.1:2181, initiating session  
2018-06-20 00:13:41,002 \[myid:\] - INFO  \[main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1302\] - Session establishment complete on server 127.0.0.1/127.0.0.1:2181, sessionid = 0x100175b98890000, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null  
  
输入命令help 显示所有命令

ZooKeeper -server host:port cmd args  
    stat path \[watch\]  
    set path data \[version\]  
    ls path \[watch\]  
    delquota \[-n|-b\] path  
    ls2 path \[watch\]  
    setAcl path acl  
    setquota -n|-b val path  
    history   
    redo cmdno  
    printwatches on|off  
    delete path \[version\]  
    sync path  
    listquota path  
    rmr path  
    get path \[watch\]  
    create \[-s\] \[-e\] path data acl  
    addauth scheme auth  
    quit   
    getAcl path  
    close   
    connect host:port  
  
注意 ls,get,stat 命令有 \[watch\]参数，可以用来监控节点的变化

命令行工具的一些常用操作命令如下：  
connect  
切换客户端

connect 127.0.0.1:2182  
1  
create  
使用create命令，可以创建一个Zookeeper节点，   
create \[-s\] \[-e\] path data acl   
其中，-s或-e分别指定节点特性，顺序或临时节点，若不指定，则表示持久节点；acl用来进行权限控制。

使用 命令创建zk-test顺序节点

\[zk: 127.0.0.1:2181(CONNECTED) 96\] create -s /zk-test 0    
Created /zk-test0000000003  
  
使用 create -e /zk-test 123 命令创建zk-test临时节点

\[zk: 127.0.0.1:2181(CONNECTED) 96\] create -s /zk-test 0    
Created /zk-test0000000003  
  
使用 create /zk-permanent 123 命令创建zk-permanent永久节点

\[zk: 127.0.0.1:2182(CONNECTED) 11\] create /zk-permanent 123  
Created /zk-permanent

//查看所有节点  
\[zk: 127.0.0.1:2182(CONNECTED) 12\] ls /  
\[test0000000000, zk-permanent, zookeeper, test, zk-test0000000003\]  
  
读取节点  
ls path \[watch\] ls命令可以列出Zookeeper指定节点下的所有第一级子节点   
get path \[watch\] 可以获取Zookeeper指定节点的数据内容和属性信息   
ls2 path \[watch\] 比ls显示更多信息

命令输出结果如下：

\[zk: 127.0.0.1:2182(CONNECTED) 12\] ls /  
\[test0000000000, zk-permanent, zookeeper, test, zk-test0000000003\]

\[zk: 127.0.0.1:2182(CONNECTED) 13\] ls /test  
\[node4, node5, node2, node3, node8, node6, node7, node1\]

\[zk: 127.0.0.1:2182(CONNECTED) 14\] get /test  
123  
cZxid = 0x200000010  
ctime = Tue Jun 19 20:00:12 PDT 2018  
mZxid = 0x200000010  
mtime = Tue Jun 19 20:00:12 PDT 2018  
pZxid = 0x300000007  
cversion = 12  
dataVersion = 0  
aclVersion = 0  
ephemeralOwner = 0x0  
dataLength = 3  
numChildren = 8

\[zk: 127.0.0.1:2182(CONNECTED) 15\] ls2 /test  
\[node4, node5, node2, node3, node8, node6, node7, node1\]  
cZxid = 0x200000010  
ctime = Tue Jun 19 20:00:12 PDT 2018  
mZxid = 0x200000010  
mtime = Tue Jun 19 20:00:12 PDT 2018  
pZxid = 0x300000007  
cversion = 12  
dataVersion = 0  
aclVersion = 0  
ephemeralOwner = 0x0  
dataLength = 3  
numChildren = 8  
  
更新节点  
使用set命令，可以更新指定节点的数据内容，用法如下

set path data \[version\]

使用命令set /test/node1 1更新节点， 每更新一次节点dataVersion 都会变化

\[zk: 127.0.0.1:2182(CONNECTED) 17\] set /test/node1 1  
cZxid = 0x200000011  
ctime = Tue Jun 19 20:00:57 PDT 2018  
mZxid = 0x30000000f  
mtime = Wed Jun 20 01:23:38 PDT 2018  
pZxid = 0x200000011  
cversion = 0  
dataVersion = 6  
aclVersion = 0  
ephemeralOwner = 0x0  
dataLength = 1  
numChildren = 0  
  
删除节点  
使用delete命令可以删除Zookeeper上的指定节点，用法如下   
delete path \[version\]   
其中version也是表示数据版本，使用delete /zk-permanent 命令即可删除/zk-permanent节点

2. 使用JAVA连接使用ZK  
POM添加引用

<dependency>  
            <groupId>org.apache.zookeeper</groupId>  
            <artifactId>zookeeper</artifactId>  
            <version>3.4.6</version>  
        </dependency>  
  
使用代码模拟增删改查

import org.apache.zookeeper.\*;  
import org.apache.zookeeper.data.Stat;

import java.io.IOException;  
import java.util.concurrent.CountDownLatch;

public class zkClient \{  
    public static void main(String\[\] args) throws IOException, KeeperException, InterruptedException \{  
        final CountDownLatch countDownLatch = new CountDownLatch(1);

ZooKeeper zk = new ZooKeeper("10.168.x.23:2181,10.168.x.23:2182,10.168.x.23:2183", 3000, new Watcher() \{  
            @Override  
            public void process(WatchedEvent event) \{  
                if (event.getState() == Event.KeeperState.SyncConnected) \{  
                    countDownLatch.countDown();  
                \}  
                System.out.println("Watch =>" + event.getType());  
            \}  
        \});  
        countDownLatch.await();

System.out.println(zk.getState());  
        String node = "/app1";  
        Stat state = zk.exists(node, false);  
        if (state == null) \{  
            System.out.println("创建节点");  
            String createResult = zk.create(node, "0".getBytes(), ZooDefs.Ids.OPEN\_ACL\_UNSAFE, CreateMode.PERSISTENT);  
            System.out.println(createResult);  
        \}

byte\[\] b = zk.getData(node, false, state);  
        System.out.println("获取data值 =》" + new String(b));

state = zk.setData(node, "1".getBytes(), state.getVersion());  
        System.out.println("after update, version changed to =>" + state.getVersion());  
        zk.delete(node,state.getVersion());  
        System.out.println("delete complete");

zk.close();  
    \}  
\}  
  
3. 使用curator连接使用ZK  
import org.apache.curator.framework.CuratorFramework;  
import org.apache.curator.framework.CuratorFrameworkFactory;  
import org.apache.curator.retry.ExponentialBackoffRetry;  
import org.apache.zookeeper.CreateMode;  
import org.apache.zookeeper.data.Stat;

public class CuratorDemo \{

final static String BasePath = "/curatorTest";

public static void main(String\[\] args) throws Exception \{  
        CuratorFramework curatorFramework = CuratorFrameworkFactory.builder().connectString("10.168.12.23:2181,10.168.12.23:2182,10.168.12.23:2183").sessionTimeoutMs(4000)  
                .retryPolicy(new ExponentialBackoffRetry(1000, 3))  
                .namespace("curator").build();

curatorFramework.start();

Stat stat = curatorFramework.checkExists().forPath(BasePath + "/node1");  
        Object o;  
        if (stat == null) \{

o=   curatorFramework.create().creatingParentContainersIfNeeded().  
                    withMode(CreateMode.PERSISTENT).forPath(BasePath + "/node1", "0".getBytes());  
        \}

//存储Stat  
        curatorFramework.getData().storingStatIn(stat).forPath(BasePath + "/node1");

//更新时使用State  
        stat = curatorFramework.setData().withVersion(stat.getVersion()).forPath(BasePath + "/node1", "1".getBytes());  
        System.out.println("update => " + stat.getVersion());

curatorFramework.close();  
    \}  
\}  
\---------------------   
作者：肥龙上天   
来源：CSDN   
原文：https://blog.csdn.net/yangsnow\_rain\_wind/article/details/80749402   
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