螞蟻課堂每特教育第五期互聯(lián)網(wǎng)架構(gòu)分布式協(xié)調(diào)工具zookeeper快速入門

1、分布式 Zookeeper 快速入門Zookeeper文檔上這么解釋 zookeeper，它是一個分布式服務(wù)框架，是 Apache Hadoop 的一個子項目，它主要是用來解決分布式應(yīng)用中經(jīng)常遇到的一些數(shù)據(jù)管理問題，如：命名服務(wù)、狀態(tài)同步服務(wù)、集群管理、分布式應(yīng)用配置項的管理等。上面的解釋有點抽象，簡單來說 zookeeper=文件系統(tǒng)+通知機制。Zookeeper 應(yīng)用場景.5.中心(Dubbo+Zookeeper)分布式配置中心(存放配置文件)分布式鎖 分布式隊列分布式文件系統(tǒng)Zookeeper 單機版本Linux 環(huán)境安裝 Zookeeper1.解壓 zk 壓縮包tar -

2、zxvf zookeeper-3.4.14.tar.gz2. 進(jìn)入到 zk 目錄cd zookeeper-3.4.143.在 zk 目錄中創(chuàng)建 data 和 logs 文件夾mkdir data mkdir logs4.進(jìn)入到 conf 目錄，修改文件名稱mv zoo_svi zoo.cfgle.cfg zoo.cfgdataDir =/usr/local/zookeeper-3.4.14/datadataLogDir=/usr/local/zookeeper-3.4.14/logs 5.啟動 zk./zkServer.sh start./zkServer.sh sus單機啟動成功注意：在安裝

3、 Zk 的時候提前安裝好jdk 環(huán)境 建議java8 以上Zookeeper 相關(guān)特性1、高效適用于大型的分布式系統(tǒng). 如果寫多的話性能不高，因為它要做所有節(jié)點之間的數(shù)據(jù)同步。2、可靠支持集群，大部分可用即服務(wù)可用3、順序所有寫請求由 leader 生成遞增 zxid，寫操作時，采用 mvcc 樂觀鎖機制進(jìn)行寫，保證所有寫操作順序。4、簡潔對外提供的 api 非常實用、簡潔。僅僅 7 個 api create - 在樹形結(jié)構(gòu)的位置中創(chuàng)建節(jié)點delete - 刪除一個節(jié)點exists - 測試節(jié)點在指定位置上是否存在get data - 從節(jié)點上數(shù)據(jù)set data - 往節(jié)點寫入輸入get c

4、hilren - 檢索一個節(jié)點的子節(jié)點列表sync - 等待傳輸數(shù)據(jù)Zookeeper 數(shù)據(jù)模型臨時節(jié)點臨時順序節(jié)點持久節(jié)點持久順序節(jié)點Java 語言操作 ZKACL 權(quán)限控制ACL 權(quán)限模型，實際上就是對樹每個節(jié)點實現(xiàn)控制的認(rèn)證有 4 種方式：world：默認(rèn)方式，相當(dāng)于全世界都能auth：代表已經(jīng)認(rèn)證通過的用戶(cli 中可以通過 addauthdigest uswd 來添加當(dāng)前上下文中的用戶)digest：即用戶名:這種方式認(rèn)證，這也是業(yè)務(wù)系統(tǒng)中最常用的ip：使用 Ip 地址認(rèn)證1.給節(jié)點設(shè)置權(quán)限/ 1.創(chuàng)建 zooKeeper 連接ZooKeeper zooKeeper = new Z

5、ooKeeper(35, 500, new Watcher() public void pros(WatchedEvent watchedEvent) / 1.創(chuàng)建 zooKeeper 連接ZooKeeper zooKeeper = new ZooKeeper(35, 500, new Watcher() public void pros(WatchedEvent watchedEvent) System.out.prln(watchedEvent.getSe().name(););/ 2.創(chuàng)建臨時節(jié)點String s1 = zooKeepe

6、r.create(/mayikt, mayikt.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);System.out.prln(s1: + s1);/ 3.創(chuàng)建持久節(jié)點String s2 = zooKeeper.create(/mayikt, mayikt.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);System.out.prln(s2: + s2);/ 4.創(chuàng)建持久節(jié)點帶順序String s3 = zooKeeper.create

7、(/mayikt, mayikt.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT_SEQUENTIAL);System.out.prln(s3: + s3);/ 5.創(chuàng)建臨時節(jié)點帶順序String s4 = zooKeeper.create(/mayikt, mayikt.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.EPHEMERAL_SEQUENTIAL);System.out.prln(s4: + s4);2.查詢該節(jié)點必須賬號實現(xiàn)服務(wù)與發(fā)現(xiàn)/ 1.創(chuàng)建 z

8、ooKeeper 連接ZooKeeper zooKeeper = new ZooKeeper(35, 500, new Watcher() public void pros(WatchedEvent watchedEvent) System.out.prln(watchedEvent.getSe().name(););/ 2.設(shè)置 zk 連接賬號zooKeeper.addAuthInfo(digest, guest:guest123.getBytes();byte bytes = zooKeeper.getData(/mayikt_6440, null, new S(

9、);String string = new String(bytes);System.out.prln(string);System.out.prln(watchedEvent.getSe().name(););/ 2.創(chuàng)建賬號權(quán)限 admin 可以實現(xiàn)讀寫操作Id id1 = new Id(digest, DigestAuthenticationProvider.generateDigest(admin:admin123);ACL acl1 = new ACL(ZooDefs.Perms.ALL, id1);/ 3.創(chuàng)建權(quán)限 guest 只允許做讀操作Id id2 = new Id(dige

10、st, DigestAuthenticationProvider.generateDigest(guest:guest123);ACL acl2 = new ACL(ZooDefs.Perms.READ, id2);/ 4.添加該賬號ArrayList a= new ArrayList();a.add(acl1);a.add(acl2);/ 5.創(chuàng)建該節(jié)點String s1 = zooKeeper.create(/memberservice, mayikt.getBytes(), a, CreateMode.PERSISTENT);System.out.prln(s1: + s1);服務(wù)端St

11、ring data = : + servort;zooKeeper.create(parentPath + / + servort, data.getBytes(),ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);Componentpublic class ApplicationRunnerImpl implements ApplicationRunner Value($servort)private String servort;Overridepublic void run(ApplicationArguments args) thro

12、ws Exception start();public void start() throws IOException, KeeperException,erruptedException ZooKeeper zooKeeper = new ZooKeeper(35, 50000, new Watcher() Overridepublic void pros(WatchedEvent watchedEvent) System.out.prln(watchedEvent.getSe().name(););String parentPath = /mayikt;Sexis

13、ts = zooKeeper.exists(parentPath, new Watcher() Overridepublic void pros(WatchedEvent event) );/ 如果當(dāng)前父節(jié)點不存在的情況 就創(chuàng)建if (exists = null) zooKeeper.create(parentPath, mayikt.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT);/ 將當(dāng)前服務(wù)信息到 zk 上客戶端獲取Zookeeper 事件通知Zookeeper Watcher 事件通知 當(dāng)節(jié)點發(fā)生變化的時候

14、修改、刪除、新增 都會到通知；相關(guān)命令service keepalived startservice keepalived stopprivate sic final CountDownLatch countDownLatch = new CountDownLatch(1);public sic void main(String args) throws IOException,erruptedException, KeeperExceptionZooKeeper zooKeeper = new ZooKeeper(35, 50000, new Watcher() O

15、verridepublic void pros(WatchedEvent watchedEvent) Event.KeeperSe se = watchedEvent.getSe();/ 如果當(dāng)前連接成功,則開始放心if (se = Event.KeeperSe.SyncConnected) System.out.prln(zk 連接成功);countDownLatch.countDown(););countDownLatch.await();String path = /mayikt;/ 獲取該節(jié)點下子集List children = zooKeeper.getChildren(path,

16、null, new S();for (i = 0; i children.size(); i+) String pathChildren = path + / + children.get(i);byte data = zooKeeper.getData(pathChildren, null, new S();System.out.prln(服務(wù)接口地址: + new String(data);systemctl stop firewalldZookeeper簡稱 zk 分布式領(lǐng)域中遇到Zookeeper 應(yīng)用場景1.分布式鎖（redis 或者 zk）分布式領(lǐng)域中協(xié)調(diào)者2.Dubbo 服務(wù)（zk）分布式配置中心 disconfig分布式消息中