bin目录下常用的脚本解释
客户端命令行操作
1.配置zookeeper的环境变量
为了执行命令方便而不用每次都进入到zookeeper的安装目录去启动命令，我们可以将zookeeper配置到系统环境变量中。方便每次的操作
vim /etc/profile
# zookeeper 配置 export ZOOKEEPER_HOME=/root/app/zookeeper-3.4.10 export PATH=$PATH:$ZOOKEEPER_HOME/bin
重新加载配置文件
source /etc/profile
2.连接zookeeper
连接当前节点上的zookeeper服务器
zkCli.sh
想要连接其他节点上的服务器
zkCli.sh -timeout 5000 -server hadoop-node03[:2181]
参数 说明
-timeout 连接超时时长
-server 需要连接的服务器地址默认端口是2181，可以省略
3.数据操作
3.1zookeeper的数据存储结构
层次化的目录结构，命名符合常规文件系统规范
每个节点在zookeeper中叫做znode，并且有一个唯一的路径标识
节点znode可以包含数据和子节点（但是EPHEMERAL类型的节点不能有子节点）
客户端应用可以在节点上设置监听器
3.2节点的类型
1).znode有两种类型：
短暂性（ephemeral）（断开连接自己删除）
持久性（persistent）（断开连接不删除）
2).znode有四种形式的目录节点（默认是persistent）如下
序号 节点类型 描述
1 PERSISTENT 持久节点
2 PERSISTENT_SEQUENTIAL 持久有序节点
3 EPHEMERAL 短暂节点
4 EPHEMERAL_SEQUENTIAL 短暂有序节点
创建znode时设置顺序标识，znode名称后会附加一个值，顺序号是一个单调递增的计数器，有父节点维护
在分布式系统中，顺序号可以被用于为所有的事件进行全局排序，这样客户端可以通过顺序号推断事件的顺序
3.3命令说明
zookeeper中的常用命令不是很多，我们可以通过help命令来查看
[zk: hadoop-node03(CONNECTED) 0] help 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
命令说明
序号 命令 说明
1 connect 在连接服务器的情况连接到其他节点上去
2 close 关闭和服务器的连接
3 ls 用于获取某个节点下的节点信息
4 ls2 ls2命令是ls命令的增强版，比ls命令多输出本节点信息
5 create 用于创建节点，其中-s为顺序节点，-e临时节点
6 delete 只能删除没有子节点的节点
7 rmr 可以删除有子节点的节点
8 get 用户获取节点信息
9 stat 查看节点的状态
10 set 设置节点的数据
11 listquota listquota命令用于显示配额,zookeeper的quota并没有实际的限制作用，超出了也只是打印WARN级别日志
12 setquota setquota命令用于设置节点个数以及数据长度的配额
13 delquota 用于删除配额，-n为子节点个数，-b为节点数据长度,如：delquota –n 2
14 history 用于列出最近的命令历史，可以和redo配合使用
15 redo 命令用于再次执行某个命令
16 addauth 用于节点认证，使用方式：如addauth digest username:password
17 setAcl setAcl命令用于设置节点Acl
Acl由三部分构成：
1为scheme，2为user，3为permission，一般情况下表示为scheme: id :permissions
18 getAcl 获取节点的Acl，如getAcl /node1
19 sync 用于强制同步，由于请求在半数以上的zk server上生效就表示此请求生效，那么就会有一些zk server上的数据是旧的。sync命令就是强制同步所有的更新操作
20 printwatchers 用于设置和显示监视状态，值为on或则off
21 quit 退出客户端
3.4常用操作
ls命令
ls命令是用来查看某个节点下的子节点信息，zookeeper的根节点是’/’,在初始的时候’/'下是没有任何子节点的
[zk: hadoop-node01(CONNECTED) 5] ls [zk: hadoop-node01(CONNECTED) 6]
创建几个节点再查看:
[zk: hadoop-node01(CONNECTED) 8] create /node1 node1 Created /node1 [zk: hadoop-node01(CONNECTED) 9] create /node2 node2 Created /node2 [zk: hadoop-node01(CONNECTED) 10] ls / [node2, zookeeper, node1]
ls2
ls2命令是ls命令的增强版，比ls命令多输出本节点信息
[zk: hadoop-node01(CONNECTED) 11] ls2 / [node2, zookeeper, node1] cZxid = 0x0 ctime = Thu Jan 01 08:00:00 CST 1970 mZxid = 0x0 mtime = Thu Jan 01 08:00:00 CST 1970 pZxid = 0x30000000c cversion = 1 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 0 numChildren = 3
节点的信息描述在下面的get命令中描述
get命令
get命令查看节点的信息
[zk: hadoop-node01(CONNECTED) 11] ls2 / [node2, zookeeper, node1] cZxid = 0x0 ctime = Thu Jan 01 08:00:00 CST 1970 mZxid = 0x0 mtime = Thu Jan 01 08:00:00 CST 1970 pZxid = 0x30000000c cversion = 1 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 0 numChildren = 3
节点信息说明
序号 属性 说明
1 cZxid Znode创建的事务id
2 ctime 节点创建时间
3 mZxid Znode被修改的事务id，即每次对znode的修改都会更新mZxid
4 mtime 节点最近一次更新的时间
5 pZxid 是与该节点的子节点（或该节点）的最近一次 创建 / 删除 的时间戳对应
6 cversion 子节点数据更新次数
7 dataVersion 本节点数据更新次数
8 aclVersion 节点ACL(授权信息)的更新次数
9 ephemeralOwner 如果该节点为临时节点,ephemeralOwner值表示与该节点绑定的session id. 如果该节点不是临时节点,ephemeralOwner值为0
10 dataLength 节点数据长度
11 numChildren 子节点个数
zxid特别说明
对于zk来说，每次的变化都会产生一个唯一的事务id,zxid（ZooKeeper Transaction Id）。通过zxid，可以确定更新操作的先后顺序。例如，如果zxid1小于zxid2，说明zxid1操作先于zxid2发生。需要指出的是，zxid对于整个zk都是唯一的，即使操作的是不同的znode。
create命令
create命令用户创建ZNode节点。
create [-s] [-e] path data acl
参数 说明
-s 有序
-e 短暂
path 节点路径及名称
data 节点保存的数据
acl 节点的权限
创建永久节点
[zk: hadoop-node01(CONNECTED) 17] create /node1/node01 node01 Created /node1/node01 [zk: hadoop-node01(CONNECTED) 19] get /node1/node01 node01 cZxid = 0x30000000d ctime = Tue Feb 26 06:00:43 CST 2019 mZxid = 0x30000000d mtime = Tue Feb 26 06:00:43 CST 2019 pZxid = 0x30000000d cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 6 numChildren = 0 [zk: hadoop-node01(CONNECTED) 20] ls /node1 [node01]
创建永久有序节点
[zk: hadoop-node01(CONNECTED) 21] create /node1/node02 node02 Created /node1/node02 [zk: hadoop-node01(CONNECTED) 22] delete /node1/node02 [zk: hadoop-node01(CONNECTED) 23] create -s /node1/node02 node02 Created /node1/node020000000002 [zk: hadoop-node01(CONNECTED) 24] get /node1/node020000000002 node02 cZxid = 0x300000010 ctime = Tue Feb 26 06:02:44 CST 2019 mZxid = 0x300000010 mtime = Tue Feb 26 06:02:44 CST 2019 pZxid = 0x300000010 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 6 numChildren = 0
永久节点即使我们断开连接后再次连接后也不会消失
[zk: hadoop-node01(CONNECTED) 25] close 2019-02-25 23:07:21,968 [myid:] - INFO [main:ZooKeeper@684] - Session: 0x16920a6e1e90000 closed [zk: hadoop-node01(CLOSED) 26] 2019-02-25 23:07:21,968 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@519] - EventThread shut down for session: 0x16920a6e1e90000 [zk: hadoop-node01(CLOSED) 26] connect 2019-02-25 23:07:33,387 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=hadoop-node01 sessionTimeout=5000 watcher=org.apache.zookeeper.ZooKeeper Main$MyWatcher@383534aa[zk: hadoop-node01(CONNECTING) 27] 2019-02-25 23:07:33,401 [myid:] - INFO [main-SendThread(hadoop-node01:2181):ClientCnxn$SendThread@1032] - Opening socket connection to server h adoop-node01/192.168.88.121:2181. Will not attempt to authenticate using SASL (unknown error)2019-02-25 23:07:33,406 [myid:] - INFO [main-SendThread(hadoop-node01:2181):ClientCnxn$SendThread@876] - Socket connection established to hadoop-node01/192.168.88.121:2181, initi ating session2019-02-25 23:07:33,423 [myid:] - INFO [main-SendThread(hadoop-node01:2181):ClientCnxn$SendThread@1299] - Session establishment complete on server hadoop-node01/192.168.88.121:21 81, sessionid = 0x16920a6e1e90001, negotiated timeout = 5000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null [zk: hadoop-node01(CONNECTED) 27] ls /node1 [node020000000002, node01]
创建短暂节点
[zk: hadoop-node01(CONNECTED) 28] create -e /node1/node03 node03 Created /node1/node03 [zk: hadoop-node01(CONNECTED) 29] ls /node1 [node020000000002, node01, node03]
创建短暂有序节点
[zk: hadoop-node01(CONNECTED) 30] create -s -e /node1/node03 node04 Created /node1/node030000000004 [zk: hadoop-node01(CONNECTED) 31] ls /node1 [node020000000002, node01, node03, node030000000004] [zk: hadoop-node01(CONNECTED) 32]
注意
短暂节点不能创建子节点
创建短暂节点的客户端断开连接后数据会被自动删除
[zk: hadoop-node01(CONNECTED) 31] ls /node1 [node020000000002, node01, node03, node030000000004] [zk: hadoop-node01(CONNECTED) 32] create -e /node1/node03/aaa aaa Ephemerals cannot have children: /node1/node03/aaa [zk: hadoop-node01(CONNECTED) 33] close 2019-02-25 23:10:35,224 [myid:] - INFO [main:ZooKeeper@684] - Session: 0x16920a6e1e90001 closed [zk: hadoop-node01(CLOSED) 34] 2019-02-25 23:10:35,224 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@519] - EventThread shut down for session: 0x16920a6e1e90001 [zk: hadoop-node01(CLOSED) 34] connect 2019-02-25 23:10:44,441 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=hadoop-node01 sessionTimeout=5000 watcher=org.apache.zookeeper.ZooKeeper Main$MyWatcher@6bc168e5[zk: hadoop-node01(CONNECTING) 35] 2019-02-25 23:10:44,446 [myid:] - INFO [main-SendThread(hadoop-node01:2181):ClientCnxn$SendThread@1032] - Opening socket connection to server h adoop-node01/192.168.88.121:2181. Will not attempt to authenticate using SASL (unknown error)2019-02-25 23:10:44,448 [myid:] - INFO [main-SendThread(hadoop-node01:2181):ClientCnxn$SendThread@876] - Socket connection established to hadoop-node01/192.168.88.121:2181, initi ating session2019-02-25 23:10:44,464 [myid:] - INFO [main-SendThread(hadoop-node01:2181):ClientCnxn$SendThread@1299] - Session establishment complete on server hadoop-node01/192.168.88.121:21 81, sessionid = 0x16920a6e1e90002, negotiated timeout = 5000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null [zk: hadoop-node01(CONNECTED) 35] ls /node1 [node020000000002, node01]
set命令
set命令用来修改节点存储的信息
[zk: hadoop-node01(CONNECTED) 39] set /node1/node01 bbbb cZxid = 0x30000000d ctime = Tue Feb 26 06:00:43 CST 2019 mZxid = 0x300000018 mtime = Tue Feb 26 06:10:45 CST 2019 pZxid = 0x30000000d cversion = 0 dataVersion = 1 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 4 numChildren = 0 [zk: hadoop-node01(CONNECTED) 40] get /node1/node01 bbbb cZxid = 0x30000000d ctime = Tue Feb 26 06:00:43 CST 2019 mZxid = 0x300000018 mtime = Tue Feb 26 06:10:45 CST 2019 pZxid = 0x30000000d cversion = 0 dataVersion = 1 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 4 numChildren = 0
delete命令
delete命令用来删除节点，但是不能删除非空的节点
[zk: hadoop-node01(CONNECTED) 41] delete /node1 Node not empty: /node1 [zk: hadoop-node01(CONNECTED) 42] create /node3 node3 Created /node3 [zk: hadoop-node01(CONNECTED) 43] delete /node3 [zk: hadoop-node01(CONNECTED) 44] ls / [node2, zookeeper, node1]
rmr命令
rmr命令也是用来删除节点的，而且rmr命令可以删除非空的节点。
[zk: hadoop-node01(CONNECTED) 45] ls /node1 [node020000000002, node01] [zk: hadoop-node01(CONNECTED) 46] rmr /node1 [zk: hadoop-node01(CONNECTED) 47] ls / [node2, zookeeper]
stat命令
stat命令查看节点的状态信息
[zk: hadoop-node01(CONNECTED) 49] stat /node2 cZxid = 0x30000000c ctime = Tue Feb 26 05:38:33 CST 2019 mZxid = 0x30000000c mtime = Tue Feb 26 05:38:33 CST 2019 pZxid = 0x30000000c cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 5 numChildren = 0
close命令
关闭和服务器的连接
[zk: hadoop-node01(CONNECTED) 50] close 2019-02-25 23:24:54,024 [myid:] - INFO [main:ZooKeeper@684] - Session: 0x16920a6e1e90002 closed [zk: hadoop-node01(CLOSED) 51] 2019-02-25 23:24:54,025 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@519] - EventThread shut down for session: 0x16920a6e1e90002 [zk: hadoop-node01(CLOSED) 51]
connect命令
再次连接服务器
[zk: hadoop-node03(CONNECTED) 0] close 2019-02-25 23:25:29,318 [myid:] - INFO [main:ZooKeeper@684] - Session: 0x3692632cde90001 closed [zk: hadoop-node03(CLOSED) 1] 2019-02-25 23:25:29,321 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@519] - EventThread shut down for session: 0x3692632cde90001 [zk: hadoop-node03(CLOSED) 1] connect hadoop-node02:2181 2019-02-25 23:25:42,251 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=hadoop-node02:2181 sessionTimeout=5000 watcher=org.apache.zookeeper.ZooK eeperMain$MyWatcher@5d22bbb7[zk: hadoop-node02:2181(CONNECTING) 2] 2019-02-25 23:25:42,263 [myid:] - INFO [main-SendThread(hadoop-node02:2181):ClientCnxn$SendThread@1032] - Opening socket connection to serv er hadoop-node02/192.168.88.122:2181. Will not attempt to authenticate using SASL (unknown error)2019-02-25 23:25:42,275 [myid:] - INFO [main-SendThread(hadoop-node02:2181):ClientCnxn$SendThread@876] - Socket connection established to hadoop-node02/192.168.88.122:2181, initi ating session2019-02-25 23:25:42,286 [myid:] - INFO [main-SendThread(hadoop-node02:2181):ClientCnxn$SendThread@1299] - Session establishment complete on server hadoop-node02/192.168.88.122:21 81, sessionid = 0x26924b577110003, negotiated timeout = 5000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null [zk: hadoop-node02:2181(CONNECTED) 2]
quit命令
退出客户端连接
[zk: hadoop-node03(CONNECTED) 0] quit Quitting... 2019-02-25 23:26:25,437 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@519] - EventThread shut down for session: 0x3692632cde90002 2019-02-25 23:26:25,438 [myid:] - INFO [main:ZooKeeper@684] - Session: 0x3692632cde90002 closed [root@hadoop-node02 ~]#
zookeeper中的事件监听
在刚开始的时候我们介绍过zookeeper的两个核心功能是存储和监听，通过上面的命令我们已经可以对数据做存储操作了，接下来看下监听操作
1.数据改变的监听
监听的是节点中的内容改变了就会触发，针对的是具体的某个节点的信息，如下:
设置对某个节点内容改变的监听
[zk: localhost:2181(CONNECTED) 0] get /node2 watch node2 cZxid = 0x30000000c ctime = Tue Feb 26 05:38:33 CST 2019 mZxid = 0x30000000c mtime = Tue Feb 26 05:38:33 CST 2019 pZxid = 0x30000000c cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 5 numChildren = 0
在其他节点上修改node2的内容观察效果
但是要注意监听效果只会触发一次！！！
2.子节点改变的监听
给node2节点绑定子节点改变的监听器
[zk: localhost:2181(CONNECTED) 2] ls /node2 watch []
然后在node2下创建新的子节点观察效果
同样此监听器也只会触发一次!!!
好了常用的命令就介绍到此，下篇文章介绍节点的监听
