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小米一面：说出几个你熟悉的 Zookeeper 命令
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先说明一下环境，溪源使用zookeeper版本为3.5.10；由于版本不同，命令语法略有差异，提前说明一下，基本原理一致性，大家可以通过帮助命令查看自己当前版本的命令语法。
# 客户端、服务器命令
切换至zookeeper安装目录下的bin目录输入以下命令启动服务器或者客户端1. 启动ZK服务: ./zkServer.sh start2. 查看ZK服务状态: ./zkServer.sh status3. 停止ZK服务: ./zkServer.sh stop4. 重启ZK服务: ./zkServer.sh restart5. 连接内部客户端: ./zkCli.sh或者./zkCli.sh -server 127.0.0.1(指定连接服务器IP):2181# 节点属性
学习zookeeper 经常先介绍一下节点属性的意义。
-`cZxid`：当前数据结点创建时的事务ID——针对于`zookeeper`数据结点的管理：我们对结点数据的一些写操作都会导致`zookeeper`自动地为我们去开启一个事务，并且自动地去为每一个事务维护一个事务`ID`- `ctime`：当前数据结点创建时的时间- `mZxid`：当前数据结点最后一次更新时的事务ID- `mtime`：当前数据结点最后一次更新时的时间- `pZxid`：当前数据节点最后一次修改**其**子节点**更改的`zxid`。修改指(增加子节点、删除子节点)，并不指其子节点的数据发生改变；- `cversion`：当前数据节点对应**子结点**的更改次数- `dataVersion`：当前结点数据的发生更改的次数- `aclVersion`：当前结点的ACL更改次数——类似`linux`的权限列表，维护的是当前结点的权限列表被修改的次数- `ephemeralOwner`：如果结点是临时结点，则表示创建该结点的会话的`SessionID`；如果是持久结点，该属性值为0- `dataLength`：当前节点的数据内容长度- `numChildren`：当前数据结点的子结点个数# 帮助命令
zookeeper 基本常用命令通过帮助查看，遇到错误命令可以直接查询语法。
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 pathCommand not found: Command not found help# 新增、节点查询
新增：create [-s] [-e] path data其中 -s 为临时命令结点，-e 结点（默认是持久结点） 查询命令：get [-s] [-w] path-s 查看节点所有信息：数据信息+节点属性值 -w 查看节点数据信息 实战
//创建持久化节点node1[zk: localhost:2181(CONNECTED) 0] create /node1 "123"Created /node1//查看node1节点属性[zk: localhost:2181(CONNECTED) 1] get -s /node1123cZxid = 0x43ctime = Wed Jul 29 21:27:31 CST 2020mZxid = 0x43mtime = Wed Jul 29 21:27:31 CST 2020pZxid = 0x43cversion = 0dataVersion = 0aclVersion = 0ephemeralOwner = 0x0dataLength = 3numChildren = 0//创建有序持久化节点[zk: localhost:2181(CONNECTED) 2] create -s /seqNode1 "seq1"Created /seqNode10000000011//查看有序持久化节点信息[zk: localhost:2181(CONNECTED) 3] get -s /seqNode10000000011seq1cZxid = 0x44ctime = Wed Jul 29 21:28:25 CST 2020mZxid = 0x44mtime = Wed Jul 29 21:28:25 CST 2020pZxid = 0x44cversion = 0dataVersion = 0aclVersion = 0ephemeralOwner = 0x0dataLength = 4numChildren = 0//创建临时节点[zk: localhost:2181(CONNECTED) 4] create -s -e /tmpNode1 "tmp"Created /tmpNode10000000012[zk: localhost:2181(CONNECTED) 5] get -s /tmpNode10000000012tmpcZxid = 0x45ctime = Wed Jul 29 21:35:28 CST 2020mZxid = 0x45mtime = Wed Jul 29 21:35:28 CST 2020pZxid = 0x45cversion = 0dataVersion = 0aclVersion = 0ephemeralOwner = 0x10029ab39130008dataLength = 3numChildren = 0# 修改节点
[zk: localhost:2181(CONNECTED) 13] set /node1 "456"[zk: localhost:2181(CONNECTED) 14] get -w /node1456[zk: localhost:2181(CONNECTED) 15] set -v 0 /node1 "234"
WATCHER::
WatchedEvent state:SyncConnected type:NodeDataChanged path:/node1[zk: localhost:2181(CONNECTED) 16] get -w /node1234# 删除节点
命令：
delete [-v version] path：可以删除，也可以指定版本号删除，此命令只能删除个别节点，如果子节点存在，则需要直接删除子节点
deleteall path：直接删除指定的所有节点
[zk: localhost:2181(CONNECTED) 0] delete /node1[zk: localhost:2181(CONNECTED) 1] get -s /node1org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /node1[zk: localhost:2181(CONNECTED) 4] create /node1 "node1"Created /node1[zk: localhost:2181(CONNECTED) 5] create /node1/node11 "node11"Created /node1/node11//使用delete删除存在子节点的节点，删除失败[zk: localhost:2181(CONNECTED) 6] delete /node1Node not empty: /node1[zk: localhost:2181(CONNECTED) 7] get -s /node1node1cZxid = 0x4fctime = Wed Jul 29 21:53:37 CST 2020mZxid = 0x4fmtime = Wed Jul 29 21:53:37 CST 2020pZxid = 0x50cversion = 1dataVersion = 0aclVersion = 0ephemeralOwner = 0x0dataLength = 5numChildren = 1[zk: localhost:2181(CONNECTED) 8] deleteall /node1[zk: localhost:2181(CONNECTED) 9] get /node1org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /node1注意：删除存在子节点时，命令不要再使用，此命令已经失效。
[zk: localhost:2181(CONNECTED) 17] rmr /node1The command 'rmr' has been deprecated. Please use 'deleteall' instead.# 查看子节点列表
命令：
ls [-s] [-w] [-R] path：
ls2 path [watch][zk: localhost:2181(CONNECTED) 19] ls /[a0000000001, b0000000002, c, hadoop, seqNode10000000011, zookeeper][zk: localhost:2181(CONNECTED) 20] ls -s /[a0000000001, b0000000002, c, hadoop, seqNode10000000011, zookeeper]cZxid = 0x0ctime = Thu Jan 01 08:00:00 CST 1970mZxid = 0x0mtime = Thu Jan 01 08:00:00 CST 1970pZxid = 0x53cversion = 22dataVersion = 0aclVersion = 0ephemeralOwner = 0x0dataLength = 0numChildren = 6
[zk: localhost:2181(CONNECTED) 21] create /node1 "node1"Created /node1//当前节点下没有子节点，返回空数组[zk: localhost:2181(CONNECTED) 22] ls /node1[][zk: localhost:2181(CONNECTED) 23] create /node1/node11 "node11"Created /node1/node11[zk: localhost:2181(CONNECTED) 24] ls /node1[node11]# 查看节点状态
使用stat命令查看节点状态，与get命令的区别是此命令不返回数据信息；
[zk: localhost:2181(CONNECTED) 25] stat /node1cZxid = 0x55ctime = Wed Jul 29 22:05:16 CST 2020mZxid = 0x55mtime = Wed Jul 29 22:05:16 CST 2020pZxid = 0x56cversion = 1dataVersion = 0aclVersion = 0ephemeralOwner = 0x0dataLength = 5numChildren = 1# 监听器
get path [watch]特殊说明命令已被废弃：
[zk: localhost:2181(CONNECTED) 27] get /node1 watch'get path [watch]' has been deprecated. Please use 'get [-s] [-w] path' instead.node1//一个窗口监听，新打开一个窗口修改节点数据[zk: localhost:2181(CONNECTED) 29] get -w /node1node1//收到修改信息[zk: localhost:2181(CONNECTED) 30]WATCHER::
WatchedEvent state:SyncConnected type:NodeDataChanged path:/node1
//另一个窗口修改节点：[zk: localhost:2181(CONNECTED) 0] set /node1 "set node1"# 权限控制
权限模式(scheme)：授权的策略
授权对象(id)：授权的对象
权限(permission)：授予的权限权限模式
| 方案 | 描述 | | --- | --- | | world | 只有一个用户：anyone，代表登录zookeeper所有人(默认) | | ip | 对客户端使用IP地址认证 | | auth | 使用已添加认证的用户认证 | | digest | 使用"用户名：密码"方式认证 |
授权对象
给谁授予权限 授权对象ID是指，权限赋予的实体，例如：IP地址或用户
权限
create、delete、read、writer、admin也就是 增、删、查、改、管理权限，这5种权限简写为 c d r w a，注意：这五种权限中，有的权限并不是对结点自身操作的例如：delete是指对子结点 的删除权限。可以试图删除父结点，但是子结点必须删除干净，所以delete的权限也是很有用的
授权的相关命令
world模式:
[zk: localhost:2181(CONNECTED) 31] getAcl /node1'world,'anyone: cdrwa[zk: localhost:2181(CONNECTED) 32] setAcl /node1 world:anyone:drwa[zk: localhost:2181(CONNECTED) 33] create /node1/node2 "node2"Authentication is not valid : /node1/node2[zk: localhost:2181(CONNECTED) 34] setAcl /node1 world:anyone:cdrwa[zk: localhost:2181(CONNECTED) 35] create /node1/node2 "node2"Created /node1/node2IP模式：需要两台虚拟机一起授权的话需要用逗号 将授权列表隔开：setAcl /ipNode ip:192.168.103.133:cdrwa,ip:192.168.103.132:cdrwa
[zk: localhost:2181(CONNECTED) 8] create /ipNode "ipNode"Created /ipNode[zk: localhost:2181(CONNECTED) 9] get -s /ipNodeipNodecZxid = 0x65ctime = Wed Jul 29 23:22:23 CST 2020mZxid = 0x65mtime = Wed Jul 29 23:22:23 CST 2020pZxid = 0x65cversion = 0dataVersion = 0aclVersion = 0ephemeralOwner = 0x0dataLength = 6numChildren = 0[zk: localhost:2181(CONNECTED) 10] setAcl /ipNode ip:192.168.16.81:ra[zk: localhost:2181(CONNECTED) 11] get -s /ipNodeorg.apache.zookeeper.KeeperException$NoAuthException: KeeperErrorCode = NoAuth for /ipNodeauth模式：命令：addauth digest :****setAcl auth::
//认证用户[zk: localhost:2181(CONNECTED) 36] addauth digest qxy:123456[zk: localhost:2181(CONNECTED) 37] get -s /node1set node1cZxid = 0x55ctime = Wed Jul 29 22:05:16 CST 2020mZxid = 0x58mtime = Wed Jul 29 22:31:29 CST 2020pZxid = 0x5ccversion = 2dataVersion = 1aclVersion = 2ephemeralOwner = 0x0dataLength = 9numChildren = 2//设置认证用户[zk: localhost:2181(CONNECTED) 38] setAcl /node1 auth:qxy:cdrwa//退出，重新进入[zk: localhost:2181(CONNECTED) 39] quit
WATCHER::
WatchedEvent state:Closed type:None path:null2020-07-29 22:58:56,574 [myid:] - INFO [main:ZooKeeper@1422] - Session: 0x10029ab39130009 closed2020-07-29 22:58:56,574 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@524] - EventThread shut down for session: 0x10029ab39130009//未用户认证，无法获取节点信息[zk: localhost:2181(CONNECTED) 0] get -s /node1org.apache.zookeeper.KeeperException$NoAuthException: KeeperErrorCode = NoAuth for /node1//认证用户，注意此处密码错误，不会提示错误，但是无法访问节点[zk: localhost:2181(CONNECTED) 1] addauth digest qxy:123456[zk: localhost:2181(CONNECTED) 2] get -s /node1set node1cZxid = 0x55ctime = Wed Jul 29 22:05:16 CST 2020mZxid = 0x58mtime = Wed Jul 29 22:31:29 CST 2020pZxid = 0x5ccversion = 2dataVersion = 1aclVersion = 3ephemeralOwner = 0x0dataLength = 9numChildren = 2Digest模式：命令：**setAcl digest:::**密码是经过SHA1以及BASE64处理的密文，在shell 中可以通过以下命令计算：
echo -n <user>:<password> | openssl dgst -binary -sha1 | openssl base64建立新的窗口，计算密码
[root@izbp14najjyuhkvm4qbic7z bin]# echo -n qxy:123456 | openssl dgst -binary -sha1 | openssl base64hDF4uLZvMJqOX2ekKFa6kSz9HNo=实战：
[zk: localhost:2181(CONNECTED) 5] create /digestNode "digestNode"Created /digestNode[zk: localhost:2181(CONNECTED) 2] setAcl /digestNode digest:qxy:hDF4uLZvMJqOX2ekKFa6kSz9HNo=:cdrwa[zk: localhost:2181(CONNECTED) 3] get /digestNodeorg.apache.zookeeper.KeeperException$NoAuthException: KeeperErrorCode = NoAuth for /digestNode[zk: localhost:2181(CONNECTED) 2] setAcl /digestNode digest:qxy:hDF4uLZvMJqOX2ekKFa6kSz9HNo=:cdrwa[zk: localhost:2181(CONNECTED) 3] get /digestNodeorg.apache.zookeeper.KeeperException$NoAuthException: KeeperErrorCode = NoAuth for /digestNode[zk: localhost:2181(CONNECTED) 4] getAcl /digestNodeAuthentication is not valid : /digestNode[zk: localhost:2181(CONNECTED) 5] addauth digest qxy:123456[zk: localhost:2181(CONNECTED) 6] getAcl /digestNode'digest,'qxy:hDF4uLZvMJqOX2ekKFa6kSz9HNo=: cdrwa[zk: localhost:2181(CONNECTED) 7] get /digestNodedigestNodeD哥也了一个技术群，主要针对一些新的技术和开源项目值不值得去研究和IDEA使用的“骚操作”，有兴趣入群的同学，可以长扫描区域二维码，一定要注意事项：城市+昵称+技术方向，根据格式备注，可快速通过。
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