一, Zookeeper 数据模型
具备目录和文件的双重特点
通过路径引用
储存数据有大小限制
三部分: 状态信息, 关联数据, 子节点
二, Znode 节点类型
永久节点: 生命周期不依赖于会话, 并且只能在客户端显式执行删除操作的时候, 才能被删除;
临时节点: 生命周期依赖于会话, 一旦会话结束, 临时节点将会被自动删除; 不能有子节点.
Znode 具有序列化特性, 如果在创建的时候指定的话, Znode 的名字后面会自动追加一个不断增加的序列号. 序列号对于此节点的父节点来说是唯一的, 这样子节点根据创建的先后顺序不同, 在名字上有不同的先后顺序(%10d: 10 位数字, 没有数值的数位用 0 补充)
三, Shell 操作
使用 zkCli.sh 连接到 zookeeper 集群之后, 如果不晓得操作有哪些, 就随便输入一些, 便会显示关于 zookeeper 的操作指令
bin/zkCli.sh -server node1:2181[zk: node1:2181(CONNECTED) 0] ls /[zookeeper][zk: node1:2181(CONNECTED) 1] helpZooKeeper -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 pathCommand not found: Command not found help[zk: node1:2181(CONNECTED) 2] ls -R ///zookeeper/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 3]
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指令的内容, 无非是对 zookeeper 这个 Znode 的增删改查
创建节点
1, PERSISTENT：永久节点
[zk: node1:2181(CONNECTED) 11] create /2021sunnyCreated /2021sunny[zk: node1:2181(CONNECTED) 13] ls /[2021sunny, zookeeper][zk: node1:2181(CONNECTED) 14] ls / -R//2021sunny/zookeeper/zookeeper/config/zookeeper/quota
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[zk: node1:2181(CONNECTED) 11] create /2021sunnyCreated /2021sunny[zk: node1:2181(CONNECTED) 13] ls /[2021sunny, zookeeper][zk: node1:2181(CONNECTED) 14] ls / -R//2021sunny/zookeeper/zookeeper/config/zookeeper/quota
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2, EPHEMERAL：临时节点
[zk: node1:2181(CONNECTED) 20] create -e /2021happyCreated /2021happy[zk: node1:2181(CONNECTED) 22] ls -R ///2021happy/2021sunny/zookeeper/zookeeper/config/zookeeper/quota
--------------------退出客户端, 重新登录zookeeper--------------------[zk: node1:2181(CONNECTED) 23] quit
WATCHER::
WatchedEvent state:Closed type:None path:null2021-01-12 11:55:37,972 [myid:] - INFO [main:ZooKeeper@1422] - Session: 0x10001ef1be90000 closed2021-01-12 11:55:37,972 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@524] - EventThread shut down for session: 0x10001ef1be90000
--------------------退出客户端, 重新登录zookeeper--------------------[zk: node1:2181(CONNECTED) 0] ls -R ///2021sunny/zookeeper/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 1]
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临时 Znode 节点原理: 该临时节点只与客户端的会话具有相同生命周期, 当前会话 session 断开, 节点自动删除.
应用场景: 集群中各个节点的存活状态管理.
3, PERSISTENT_SEQUENTIAL：永久节点、序列化
[zk: node1:2181(CONNECTED) 0] ls -R ///2021sunny/zookeeper/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 1] create -s /2021sunny/nodeCreated /2021sunny/node0000000003[zk: node1:2181(CONNECTED) 2] create -s /2021sunny/nodeCreated /2021sunny/node0000000004[zk: node1:2181(CONNECTED) 3] create -s /2021sunny/nodeCreated /2021sunny/node0000000005[zk: node1:2181(CONNECTED) 4] ls -r /org.apache.commons.cli.UnrecognizedOptionException: Unrecognized option: -r[zk: node1:2181(CONNECTED) 5] ls -R ///2021sunny/zookeeper/2021sunny/node0000000003/2021sunny/node0000000004/2021sunny/node0000000005/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 6]
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4, EPHEMERAL_SEQUENTIAL：临时节点、序列化
WatchedEvent state:SyncConnected type:None path:null[zk: node1:2181(CONNECTED) 0] ls /[2021sunny, zookeeper][zk: node1:2181(CONNECTED) 1] create -e -s /2021sunny/cnodeCreated /2021sunny/cnode0000000000[zk: node1:2181(CONNECTED) 2] create -e -s /2021sunny/cnodeCreated /2021sunny/cnode0000000001[zk: node1:2181(CONNECTED) 3] create -e -s /2021sunny/cnodeCreated /2021sunny/cnode0000000002[zk: node1:2181(CONNECTED) 4] ls -R ///2021sunny/zookeeper/2021sunny/cnode0000000000/2021sunny/cnode0000000001/2021sunny/cnode0000000002/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 5]
--------------------退出客户端, 重新登录zookeeper--------------------[zk: node1:2181(CONNECTED) 23] quit
--------------------退出客户端, 重新登录zookeeper--------------------[zk: node1:2181(CONNECTED) 0] ls -R ///2021sunny/zookeeper/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 1]
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查看节点
上面已经试验了 ls 以及 ls -R 的使用效果
下面查看 ls2 的效果: 使用 ls -s 替代了, 也就是展示详细信息
[zk: node1:2181(CONNECTED) 7] ls2 /'ls2' has been deprecated. Please use 'ls [-s] path' instead.[zookeeper, 2021sunny]cZxid = 0x0ctime = Thu Jan 01 08:00:00 CST 1970mZxid = 0x0mtime = Thu Jan 01 08:00:00 CST 1970pZxid = 0x100000000ccversion = 6dataVersion = 0aclVersion = 0ephemeralOwner = 0x0dataLength = 0numChildren = 2
[zk: node1:2181(CONNECTED) 8] ls2 /2021sunny'ls2' has been deprecated. Please use 'ls [-s] path' instead.[node0000000003, node0000000004, node0000000005]cZxid = 0x1000000002ctime = Tue Jan 12 11:49:28 CST 2021mZxid = 0x1000000005mtime = Tue Jan 12 11:50:43 CST 2021pZxid = 0x1000000015cversion = 9dataVersion = 2aclVersion = 0ephemeralOwner = 0x0dataLength = 14numChildren = 3[zk: node1:2181(CONNECTED) 9]
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设置 or 更新节点数据
作用: 给 Znode 节点设置值和获取值
[zk: node1:2181(CONNECTED) 16] set /2021sunny/node0000000003 "work hard"[zk: node1:2181(CONNECTED) 17] get /2021sunny/node0000000003 work hard[zk: node1:2181(CONNECTED) 18] ls -s /2021sunny/node0000000003[]cZxid = 0x1000000013ctime = Tue Jan 12 12:02:39 CST 2021mZxid = 0x1000000016mtime = Tue Jan 12 12:07:26 CST 2021pZxid = 0x1000000013cversion = 0dataVersion = 1aclVersion = 0ephemeralOwner = 0x0dataLength = 9numChildren = 0
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删除节点
[zk: node1:2181(CONNECTED) 34] ls -R ///2021sunny/zookeeper/2021sunny/node0000000003/2021sunny/node0000000004/2021sunny/node0000000005/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 35] delete /2021sunny/node0000000003[zk: node1:2181(CONNECTED) 36] ls -R ///2021sunny/zookeeper/2021sunny/node0000000004/2021sunny/node0000000005/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 37]
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删除所有: rmr(已经过时), 提示使用 deleteall
[zk: node1:2181(CONNECTED) 57] rmr /2021sunnyThe command 'rmr' has been deprecated. Please use 'deleteall' instead.[zk: node1:2181(CONNECTED) 58] ls -R ///zookeeper/zookeeper/config/zookeeper/quota[zk: node1:2181(CONNECTED) 59]
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列出历史操作记录
作用: 罗列出当前 session 中的所有历史操作
[zk: node1:2181(CONNECTED) 6] history0 - ls -R /1 - create -s /2021sunny/node2 - create -s /2021sunny/node3 - create -s /2021sunny/node4 - ls -r /5 - ls -R /6 - history
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