ZooKeeper的shell操作
Zookeeper的shell操作
Zookeeper命令工具
在启动Zookeeper服务之后,输入以下命令,连接到Zookeeper服务:
[[email protected] ~]$ zkCli.sh -server hadoop2:2181
1 [[email protected] ~]$ zkCli.sh -server hadoop2:2181 2 Connecting to hadoop2:2181 3 2018-03-21 19:55:53,744 [myid:] - INFO [main:[email protected]] - Client environment:zookeeper.version=3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f, built on 03/23/2017 10:13 GMT 4 2018-03-21 19:55:53,748 [myid:] - INFO [main:[email protected]] - Client environment:host.name=hadoop1 5 2018-03-21 19:55:53,749 [myid:] - INFO [main:[email protected]] - Client environment:java.version=1.8.0_73 6 2018-03-21 19:55:53,751 [myid:] - INFO [main:[email protected]] - Client environment:java.vendor=Oracle Corporation 7 2018-03-21 19:55:53,751 [myid:] - INFO [main:[email protected]] - Client environment:java.home=/usr/local/jdk1.8.0_73/jre 8 2018-03-21 19:55:53,751 [myid:] - INFO [main:[email protected]] - Client environment:java.class.path=/home/hadoop/apps/zookeeper-3.4.10/bin/../build/classes:/home/hadoop/apps/zookeeper-3.4.10/bin/../build/lib/*.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../lib/slf4j-log4j12-1.6.1.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../lib/slf4j-api-1.6.1.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../lib/netty-3.10.5.Final.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../lib/log4j-1.2.16.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../lib/jline-0.9.94.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../zookeeper-3.4.10.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../src/java/lib/*.jar:/home/hadoop/apps/zookeeper-3.4.10/bin/../conf::/usr/local/jdk1.8.0_73/lib:/usr/local/jdk1.8.0_73/jre/lib 9 2018-03-21 19:55:53,751 [myid:] - INFO [main:[email protected]] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib 10 2018-03-21 19:55:53,751 [myid:] - INFO [main:[email protected]] - Client environment:java.io.tmpdir=/tmp 11 2018-03-21 19:55:53,751 [myid:] - INFO [main:[email protected]] - Client environment:java.compiler=<NA> 12 2018-03-21 19:55:53,752 [myid:] - INFO [main:[email protected]] - Client environment:os.name=Linux 13 2018-03-21 19:55:53,752 [myid:] - INFO [main:[email protected]] - Client environment:os.arch=amd64 14 2018-03-21 19:55:53,752 [myid:] - INFO [main:[email protected]] - Client environment:os.version=2.6.32-573.el6.x86_64 15 2018-03-21 19:55:53,752 [myid:] - INFO [main:[email protected]] - Client environment:user.name=hadoop 16 2018-03-21 19:55:53,752 [myid:] - INFO [main:[email protected]] - Client environment:user.home=/home/hadoop 17 2018-03-21 19:55:53,752 [myid:] - INFO [main:[email protected]] - Client environment:user.dir=/home/hadoop 18 2018-03-21 19:55:53,755 [myid:] - INFO [main:[email protected]] - Initiating client connection, connectString=hadoop2:2181 sessionTimeout=30000 [email protected] 19 Welcome to ZooKeeper! 20 2018-03-21 19:55:53,789 [myid:] - INFO [main-SendThread(hadoop2:2181):[email protected]] - Opening socket connection to server hadoop2/192.168.123.103:2181. Will not attempt to authenticate using SASL (unknown error) 21 JLine support is enabled 22 2018-03-21 19:55:53,931 [myid:] - INFO [main-SendThread(hadoop2:2181):[email protected]] - Socket connection established to hadoop2/192.168.123.103:2181, initiating session 23 2018-03-21 19:55:53,977 [myid:] - INFO [main-SendThread(hadoop2:2181):[email protected]] - Session establishment complete on server hadoop2/192.168.123.103:2181, sessionid = 0x262486284b70000, negotiated timeout = 30000 24 25 WATCHER:: 26 27 WatchedEvent state:SyncConnected type:None path:null 28 [zk: hadoop2:2181(CONNECTED) 0]
连接成功之后,系统会输出Zookeeper的相关环境及配置信息,并在屏幕输出“welcome to Zookeeper!”等信息。
输入help之后,屏幕会输出可用的Zookeeper命令,如下图所示
使用Zookeeper命令的简单操作步骤
(1) 使用ls命令查看当前Zookeeper中所包含的内容:ls /
[zk: hadoop2:2181(CONNECTED) 1] ls / [zookeeper] [zk: hadoop2:2181(CONNECTED) 2]
(2) 创建一个新的Znode节点"aa",以及和它相关字符,执行命令:create /aa "my first zk",默认是不带编号的
[zk: hadoop2:2181(CONNECTED) 2] create /aa "my first zk" Created /aa [zk: hadoop2:2181(CONNECTED) 3]
创建带编号的持久性节点"bb",
[zk: localhost:2181(CONNECTED) 1] create -s /bb "bb" Created /bb0000000001 [zk: localhost:2181(CONNECTED) 2]
创建不带编号的临时节点"cc"
[zk: localhost:2181(CONNECTED) 2] create -e /cc "cc" Created /cc [zk: localhost:2181(CONNECTED) 3]
创建带编号的临时节点"dd"
[zk: localhost:2181(CONNECTED) 3] create -s -e /dd "dd" Created /dd0000000003 [zk: localhost:2181(CONNECTED) 4]
(3) 再次使用ls命令来查看现在Zookeeper的中所包含的内容:ls /
[zk: localhost:2181(CONNECTED) 4] ls /
[cc, dd0000000003, zookeeper, bb0000000001]
[zk: localhost:2181(CONNECTED) 5]
此时看到,aa节点已经被创建。
关闭本次连接回话session,再重新打开一个连接
[zk: localhost:2181(CONNECTED) 5] close 2018-03-22 13:03:29,137 [myid:] - INFO [main:[email protected]684] - Session: 0x1624c10e8d90000 closed [zk: localhost:2181(CLOSED) 6] 2018-03-22 13:03:29,139 [myid:] - INFO [main-EventThread:[email protected]519] - EventThread shut down for session: 0x1624c10e8d90000
[zk: localhost:2181(CLOSED) 6] ls /
Not connected
[zk: localhost:2181(CLOSED) 7] connect hadoop1:2181
重新查看,临时节点已经随着上一次的会话关闭自动删除了
[zk: hadoop1:2181(CONNECTED) 8] ls / [zookeeper, bb0000000001] [zk: hadoop1:2181(CONNECTED) 9]
(4) 使用get命令来确认第二步中所创建的Znode是否包含我们创建的字符串,执行命令:get /aa
[zk: hadoop2:2181(CONNECTED) 4] get /aa my first zk cZxid = 0x100000002 ctime = Wed Mar 21 20:01:02 CST 2018 mZxid = 0x100000002 mtime = Wed Mar 21 20:01:02 CST 2018 pZxid = 0x100000002 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 11 numChildren = 0 [zk: hadoop2:2181(CONNECTED) 5]
(5) 接下来通过set命令来对zk所关联的字符串进行设置,执行命令:set /aa haha123
[zk: hadoop2:2181(CONNECTED) 6] set /aa haha123 cZxid = 0x100000002 ctime = Wed Mar 21 20:01:02 CST 2018 mZxid = 0x100000004 mtime = Wed Mar 21 20:04:10 CST 2018 pZxid = 0x100000002 cversion = 0 dataVersion = 1 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 7 numChildren = 0 [zk: hadoop2:2181(CONNECTED) 7]
(6) 再次使用get命令来查看,上次修改的内容,执行命令:get /aa
[zk: hadoop2:2181(CONNECTED) 7] get /aa haha123 cZxid = 0x100000002 ctime = Wed Mar 21 20:01:02 CST 2018 mZxid = 0x100000004 mtime = Wed Mar 21 20:04:10 CST 2018 pZxid = 0x100000002 cversion = 0 dataVersion = 1 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 7 numChildren = 0 [zk: hadoop2:2181(CONNECTED) 8]
(7) 下面我们将刚才创建的Znode删除,执行命令:delete /aa
[zk: hadoop2:2181(CONNECTED) 8] delete /aa [zk: hadoop2:2181(CONNECTED) 9]
(8) 最后再次使用ls命令查看Zookeeper中的内容,执行命令:ls /
[zk: hadoop2:2181(CONNECTED) 9] ls / [zookeeper] [zk: hadoop2:2181(CONNECTED) 10]
经过验证,zk节点已经删除。
(9) 退出,执行命令:quit
[zk: hadoop2:2181(CONNECTED) 10] quit Quitting... 2018-03-21 20:07:11,133 [myid:] - INFO [main:[email protected]] - Session: 0x262486284b70000 closed 2018-03-21 20:07:11,139 [myid:] - INFO [main-EventThread:[email protected]] - EventThread shut down for session: 0x262486284b70000 [[email protected] ~]$
状态信息
查看一个文件的状态信息
[zk: localhost:2181(CONNECTED) 1] stat /a cZxid = 0x200000009 ctime = Thu Mar 22 13:07:19 CST 2018 mZxid = 0x200000009 mtime = Thu Mar 22 13:07:19 CST 2018 pZxid = 0x200000009 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 1 numChildren = 0 [zk: localhost:2181(CONNECTED) 2]
详细解释:
zxid: 一个事务编号,zookeeper集群内部的所有事务,都有一个全局的唯一的顺序的编号
它由两部分组成: 就是一个 64位的长整型 long
高32位: 用来标识leader关系是否改变,如 0x2
低32位: 用来做当前这个leader领导期间的全局的递增的事务编号,如 00000009
状态属性 | 说明 |
cZxid | 数据节点创建时的事务ID |
ctime | 数据节点创建时的时间 |
mZxid | 数据节点最后一次更新时的事务ID |
mtime | 数据节点最后一次更新时的时间 |
pZxid | 数据节点的子节点列表最后一次被修改(是子节点列表变更,而不是子节点内容变更)时的事务ID |
cversion | 子节点的版本号 |
dataVersion | 数据节点的版本号 |
aclVersion | 数据节点的ACL版本号 |
ephemeralOwner | 如果节点是临时节点,则表示创建该节点的会话的SessionID;如果节点是持久节点,则该属性值为0 |
dataLength | 数据内容的长度 |
numChildren | 数据节点当前的子节点个数 |
(1)修改节点a的数据,mZxid、dataVersion、dataLength 存储信息发生变化
[zk: localhost:2181(CONNECTED) 2] set /a 'aaa' cZxid = 0x200000009 ctime = Thu Mar 22 13:07:19 CST 2018 mZxid = 0x20000000a mtime = Thu Mar 22 13:12:53 CST 2018 pZxid = 0x200000009 cversion = 0 dataVersion = 1 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 3 numChildren = 0 [zk: localhost:2181(CONNECTED) 3]
(2)创建新的节点b,状态信息都会发生变化,zxid的事物ID也会增加
[zk: localhost:2181(CONNECTED) 5] stat /b cZxid = 0x20000000b ctime = Thu Mar 22 13:15:56 CST 2018 mZxid = 0x20000000b mtime = Thu Mar 22 13:15:56 CST 2018 pZxid = 0x20000000b cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 1 numChildren = 0 [zk: localhost:2181(CONNECTED) 6]
(3)在a节点下面新增节点c,pZxid、cversion、numChildren 发生改变
[zk: localhost:2181(CONNECTED) 6] create /a/c 'c' Created /a/c [zk: localhost:2181(CONNECTED) 7] stat /a cZxid = 0x200000009 ctime = Thu Mar 22 13:07:19 CST 2018 mZxid = 0x20000000a mtime = Thu Mar 22 13:12:53 CST 2018 pZxid = 0x20000000c cversion = 1 dataVersion = 1 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 3 numChildren = 1 [zk: localhost:2181(CONNECTED) 8]
(4)ephemeralOwner 持久性的节点信息是0x0临时的几点信息是本次会话的sessionid,如图
(5) 将leader干掉,此时第二台机器成为leader,重新创建一个文件y,此时发现czxid的前3位和之前发生变化,说明换了leader
[zk: localhost:2181(CONNECTED) 0] create /y 'yy' Created /y [zk: localhost:2181(CONNECTED) 2] stat /y cZxid = 0x300000003 ctime = Thu Mar 22 13:25:51 CST 2018 mZxid = 0x300000003 mtime = Thu Mar 22 13:25:51 CST 2018 pZxid = 0x300000003 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 2 numChildren = 0 [zk: localhost:2181(CONNECTED) 3]