参考地址为:https://www.cnblogs.com/sherrykid/p/5813148.html
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1.连接
在 bin 目录下的? zkCli.sh? 就是ZooKeeper客户端
./zkCli.sh -timeout 5000? -server 127.0.0.1:2181 客户端与ZooKeeper建立链接
timeout:超时时间,单位毫秒
r:只读模式,当节点坏掉的时候,还可以提供读服务
示例:
./zkCli.sh -timeout 5000? -server 127.0.0.1:2181
Connecting to 127.0.0.1:2181 2018-09-19 16:48:35,332 [myid:] - INFO? [main:Environment@100] - Client environment:zookeeper.version=3.4.6-1569965,built on 02/20/2014 09:09 GMT 2018-09-19 16:48:35,336 [myid:] - INFO? [main:Environment@100] - Client environment:host.name=iZ2ze4wl2jm5gr50lqkcu2Z 2018-09-19 16:48:35,337 [myid:] - INFO? [main:Environment@100] - Client environment:java.version=1.8.0_181 2018-09-19 16:48:35,339 [myid:] - INFO? [main:Environment@100] - Client environment:java.vendor=Oracle Corporation 2018-09-19 16:48:35,339 [myid:] - INFO? [main:Environment@100] - Client environment:java.home=/usr/lib/jvm/java-8-oracle/jre 2018-09-19 16:48:35,339 [myid:] - INFO? [main:Environment@100] - Client environment:java.class.path=/usr/local/zookeeper-3.4.6/bin/../build/classes:/usr/local/zookeeper-3.4.6/bin/../build/lib/*.jar:/usr/local/zookeeper-3.4.6/bin/../lib/slf4j-log4j12-1.6.1.jar:/usr/local/zookeeper-3.4.6/bin/../lib/slf4j-api-1.6.1.jar:/usr/local/zookeeper-3.4.6/bin/../lib/netty-3.7.0.Final.jar:/usr/local/zookeeper-3.4.6/bin/../lib/log4j-1.2.16.jar:/usr/local/zookeeper-3.4.6/bin/../lib/jline-0.9.94.jar:/usr/local/zookeeper-3.4.6/bin/../zookeeper-3.4.6.jar:/usr/local/zookeeper-3.4.6/bin/../src/java/lib/*.jar:/usr/local/zookeeper-3.4.6/bin/../conf: 2018-09-19 16:48:35,339 [myid:] - INFO? [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib 2018-09-19 16:48:35,340 [myid:] - INFO? [main:Environment@100] - Client environment:java.io.tmpdir=/tmp 2018-09-19 16:48:35,340 [myid:] - INFO? [main:Environment@100] - Client environment:java.compiler=<NA> 2018-09-19 16:48:35,340 [myid:] - INFO? [main:Environment@100] - Client environment:os.name=Linux 2018-09-19 16:48:35,340 [myid:] - INFO? [main:Environment@100] - Client environment:os.arch=amd64 2018-09-19 16:48:35,340 [myid:] - INFO? [main:Environment@100] - Client environment:os.version=4.4.0-117-generic 2018-09-19 16:48:35,340 [myid:] - INFO? [main:Environment@100] - Client environment:user.name=root 2018-09-19 16:48:35,341 [myid:] - INFO? [main:Environment@100] - Client environment:user.home=/root 2018-09-19 16:48:35,341 [myid:] - INFO? [main:Environment@100] - Client environment:user.dir=/usr/local/zookeeper-3.4.6/bin 2018-09-19 16:48:35,344 [myid:] - INFO? [main:ZooKeeper@438] - Initiating client connection,connectString=127.0.0.1:2181 sessionTimeout=5000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@506c589e Welcome to ZooKeeper! 2018-09-19 16:48:35,410 [myid:] - INFO? [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@975] - Opening socket connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error) JLine support is enabled 2018-09-19 16:48:35,580 [myid:] - INFO? [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@852] - Socket connection established to 127.0.0.1/127.0.0.1:2181,initiating session 2018-09-19 16:48:35,591 [myid:] - INFO? [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1235] - Session establishment complete on server 127.0.0.1/127.0.0.1:2181,sessionid = 0x165f0e74c000003,negotiated timeout = 5000
WATCHER::
WatchedEvent state:SyncConnected type:None path:null 如上,表示我们和ZooKeeper建立了连接,可以通过命令与ZooKeeper进行交互了
2.查看命令帮助 h 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 ?? ? ?? ?显示能够执行的命令
命令分类和数据库相似,大概可以分为增删改查四类
ZooKeeper数据结构:
zookeeper.png放到桌面
大多数时候,我们对ZooKeeper的操作都是在对节点进行增删改查
常用命令:
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查询相关指令
ls path:列出path下的文件
[zk: 127.0.0.1:2181(CONNECTED) 4] ls / [zookeeper]
如上:列出根目录节点下的所有文件,目前就只有一个系统自带的zookeeper节点
stat path:查看节点状态
[zk: 127.0.0.1:2181(CONNECTED) 6] stat /zookeeper cZxid = 0x0 ctime = Thu Jan 01 08:00:00 CST 1970 mZxid = 0x0 mtime = Thu Jan 01 08:00:00 CST 1970 pZxid = 0x0 cversion = -1 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 0 numChildren = 1
cZxid:创建节点时的事务id pZxid:子节点列表最后一次被修改的事务id cversion:节点版本号 dataCersion:数据版本号 aclVerson:acl权限版本号
get path:获取指定节点的内容
ls2 path:列出path节点的子节点及状态信息
3.创建指令 create [-s] [-e] path data acl
1 [zk: 127.0.0.1:2181(CONNECTED) 10] create /node_1 123 2 Created /node_1
如上:在根目录创建了node_1节点,携带数据 123
使用 get /node_1 验证是否添加节点及其数据成功
[zk: 127.0.0.1:2181(CONNECTED) 15] create -e /node_1/node_1_1 234 Created /node_1/node_1_1 创建了一个临时节点(-e),并且携带数据234,使用stat命令查看这个新建的临时节点
[zk: 127.0.0.1:2181(CONNECTED) 16] stat /node_1/node_1_1 cZxid = 0x200000003 ctime = Sat Aug 27 15:27:30 CST 2016 mZxid = 0x200000003 mtime = Sat Aug 27 15:27:30 CST 2016 pZxid = 0x200000003 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x156cacb918b0000 dataLength = 3 numChildren = 0
ephemeralOwner值不再是0,表示这个临时节点的版本号,如果是永久节点则其值为 0x0 1 [zk: 127.0.0.1:2181(CONNECTED) 1] create -s /node_1/node_1_1 234 2 Created /node_1/node_1_10000000001 通过使用-s参数,创建一个顺序节点,我们虽然指定的节点名是node_1_1,但是实际上,名称却是 node_1_10000000001,如果我们重复执行:
[zk: 127.0.0.1:2181(CONNECTED) 2] create -s /node_1/node_1_1 234 Created /node_1/node_1_10000000002 效果如上
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这个特性,我们可以利用一下,生成在分布式环境下的主键生成器
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-s 和 -e 可以同时使用
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4.退出: quit [zk: 127.0.0.1:2181(CONNECTED) 19] quit Quitting... 2016-08-27 15:29:44,760 [myid:] - INFO? [main:ZooKeeper@684] - Session: 0x156cacb918b0000 closed 2016-08-27 15:29:44,763 [myid:] - INFO? [main-EventThread:ClientCnxn$EventThread@519] - EventThread shut down for session: 0x156cacb918b0000 这个时候如果重新登录,执行 ls /node_1,发现其子节点是空的,创建的node_1_1子节点不见了,那是因为之前创建的时候就已经指定了,我们创建的是一个临时节点。当客户端会话结束后,临时节点是会被删除了。
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5.修改相关指定:
set path data [version]
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复制代码 [zk: 127.0.0.1:2181(CONNECTED) 14] set /node_1 998 cZxid = 0x200000002 ctime = Sat Aug 27 15:24:39 CST 2016 mZxid = 0x20000000a mtime = Sat Aug 27 15:38:40 CST 2016 pZxid = 0x200000008 cversion = 5 dataVersion = 2 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 3 numChildren = 3 复制代码 如果我们多次修改,会发现? dataVersion ,也就是数据版本,在不停得发生变化(自增)
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如果我们在set的时候手动去指定了版本号,就必须和上一次查询出来的结果一致,否则 就会报错。
这个可以用于我们在修改节点数据的时候,保证我们修改前数据没被别人修改过。因为如果别人修改过了,我们这次修改是不会成功的
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6.删除指令:
delete path [version]
删除指定节点数据,其version参数的作用于set指定一致
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delete /node_1/node_1_10000000001 整个节点全删除
注意:delete只能删除不包含子节点的节点,如果要删除的节点包含子节点,使用rmr命令
rmr /node_1 (编辑:李大同)
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