ZooKeeper命令行工具zkCli.sh
1.简介
ZooKeeper提供了一个非常简单的命令行客户端zkCli,它在ZooKeeper安装目录的bin目录下。
[root@node02 ~]# ls /usr/local/zookeeper/bin/ README.txt zkCleanup.sh zkCli.cmd zkCli.sh zkEnv.cmd zkEnv.sh zkServer.cmd zkServer.sh
先连接一个已经启动的ZooKeeper实例。例如:
[root@node02 ~]# zkCli.sh -server localhost:2181 Connecting to localhost:2181 2020-03-06 14:47:51,339 [myid:] - INFO [main:Environment@100] - Client environment:zookeeper.version=3.4.7-1713338, built on 11/09/2015 04:32 GMT 2020-03-06 14:47:51,342 [myid:] - INFO [main:Environment@100] - Client environment:host.name=node02 2020-03-06 14:47:51,342 [myid:] - INFO [main:Environment@100] - Client environment:java.version=1.8.0_191 2020-03-06 14:47:51,344 [myid:] - INFO [main:Environment@100] - Client environment:java.vendor=Oracle Corporation 2020-03-06 14:47:51,344 [myid:] - INFO [main:Environment@100] - Client environment:java.home=/usr/local/jdk1.8.0_191/jre 2020-03-06 14:47:51,344 [myid:] - INFO [main:Environment@100] - Client environment:java.class.path=/usr/local/zookeeper/bin/../build/classes:/usr/local/zookeeper/bin/../build/lib/*.jar:/usr/local/zookeeper/bin/../lib/slf4j-log4j12-1.6.1.jar:/usr/local/zookeeper/bin/../lib/slf4j-api-1.6.1.jar:/usr/local/zookeeper/bin/../lib/netty-3.7.0.Final.jar:/usr/local/zookeeper/bin/../lib/log4j-1.2.16.jar:/usr/local/zookeeper/bin/../lib/jline-0.9.94.jar:/usr/local/zookeeper/bin/../zookeeper-3.4.7.jar:/usr/local/zookeeper/bin/../src/java/lib/*.jar:/usr/local/zookeeper/bin/../conf: 2020-03-06 14:47:51,344 [myid:] - INFO [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:java.io.tmpdir=/tmp 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:java.compiler=<NA> 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:os.name=Linux 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:os.arch=amd64 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:os.version=3.10.0-693.el7.x86_64 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:user.name=root 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:user.home=/root 2020-03-06 14:47:51,345 [myid:] - INFO [main:Environment@100] - Client environment:user.dir=/root 2020-03-06 14:47:51,346 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=localhost:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@1a86f2f1 Welcome to ZooKeeper! 2020-03-06 14:47:51,401 [myid:] - INFO [main-SendThread(localhost:2181):ClientCnxn$SendThread@1032] - Opening socket connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error) JLine support is enabled 2020-03-06 14:47:51,576 [myid:] - INFO [main-SendThread(localhost:2181):ClientCnxn$SendThread@876] - Socket connection established to localhost/127.0.0.1:2181, initiating session 2020-03-06 14:47:51,608 [myid:] - INFO [main-SendThread(localhost:2181):ClientCnxn$SendThread@1299] - Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x370ae8d1f490000, negotiated timeout = 30000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null [zk: localhost:2181(CONNECTED) 0]
连接过程中会输出一大堆信息。当连接成功后,将进入ZooKeeper的交互式模式:
WatchedEvent state:SyncConnected type:None path:null [zk: localhost:2181(CONNECTED) 0] # 在这里输入ZooKeeper允许的命令
例如,输入help输出帮助信息
[zk: localhost:2181(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 [zk: localhost:2181(CONNECTED) 1]
其中交互式命令提示符中有一个不断递增的数字,例如上面执行依次操作后,从0变成1。这个数字代表的是命令的历史编号。
也可以使用zkCli.sh的非交互式模式来执行一次性操作,格式为:
zkCli.sh -server IP:PORT COMMAND
例如help命令:
zkCli.sh -server localhost:2181 help
在交互式环境中,可以使用TAB键补全,或列出可用的命令、路径。就像bash一样。
ZooKeeper的命令很少很简单,大致分为几个类型:
create:在树中的某个位置创建一个节点。 delete:删除一个节点。 exists:测试一个节点是否存在。 get data:读取节点数据。 set data:向节点中写入数据。 get children:检索某节点的子节点列表。 sync:等待要传播的数据。
注意,这只是命令的功能类型,并不意味着它们就是命令。
2.创建znode
create [-s] [-e] path data acl
-s:创建的是带序列号的节点,序列号用0填充节点路径。 -e:创建的是临时节点。 path:znode的路径,ZooKeeper中没有相对路径,所有路径都必须以'/'开头。 data:znode携带的数据。 acl:这个节点的ACL。
例如,创建一个znode节点:
[zk: localhost:2181(CONNECTED) 1] create /zk_test mydata1 Created /zk_test
其中/zk_test
是节点名称,mydata1
是该节点携带的数据。
创建一个子节点:
[zk: localhost:2181(CONNECTED) 2] create /zk_test/child_node1 "mydata2" Created /zk_test/child_node1
创建一个带序列号的znode:
[zk: localhost:2181(CONNECTED) 3] create -s /test1 222 Created /test10000000002
注意,创建了带序列号的znode后,以后只能使用带序列号的路径/test10000000003
来引用这个znode,而不能用/test1
来引用。
创建一个临时znode:
[zk: localhost:2181(CONNECTED) 4] create -e /test2 333 Created /test2
临时znode在会话退出时会自动删除,所以不能在临时节点上创建子节点。另外,虽然临时节点属于某会话,但所有客户端都可以查看、引用它。
3.查看节点的数据和状态信息
[zk: localhost:2181(CONNECTED) 5] get /zk_test mydata1 cZxid = 0x200000002 ctime = Fri Mar 06 14:56:29 CST 2020 mZxid = 0x200000002 mtime = Fri Mar 06 14:56:29 CST 2020 pZxid = 0x200000003 cversion = 1 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 7 numChildren = 1 [zk: localhost:2181(CONNECTED) 6] get /zk_test/child_node1 mydata2 cZxid = 0x200000003 ctime = Fri Mar 06 14:57:16 CST 2020 mZxid = 0x200000003 mtime = Fri Mar 06 14:57:16 CST 2020 pZxid = 0x200000003 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 7 numChildren = 0
如果只是要获取节点的状态信息,可以使用stat命令:
[zk: localhost:2181(CONNECTED) 7] stat /zk_test cZxid = 0x200000002 ctime = Fri Mar 06 14:56:29 CST 2020 mZxid = 0x200000002 mtime = Fri Mar 06 14:56:29 CST 2020 pZxid = 0x200000003 cversion = 1 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 7 numChildren = 1
ls2
命令是ls
和stat
两个命令的结合体,可以获取给定节点下的子节点,以及给定节点的状态信息:
[zk: localhost:2181(CONNECTED) 8] ls2 / [test2, zookeeper, test_znode, zk_test, test10000000002] # 子节点列表 cZxid = 0x0 ctime = Thu Jan 01 08:00:00 CST 1970 mZxid = 0x0 mtime = Thu Jan 01 08:00:00 CST 1970 pZxid = 0x200000005 cversion = 3 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 0 numChildren = 5 # 子节点数量
4.查看子节点
ls
命令查看某节点下的子节点。注意,不会递归检索。
[zk: localhost:2181(CONNECTED) 9] ls / [test2, zookeeper, test_znode, zk_test, test10000000002] [zk: localhost:2181(CONNECTED) 10] ls /zk_test [child_node1]
5.修改节点数据
set
命令用于修改节点:
[zk: localhost:2181(CONNECTED) 11] set /zk_test "mydata2" cZxid = 0x200000002 ctime = Fri Mar 06 14:56:29 CST 2020 mZxid = 0x200000006 mtime = Fri Mar 06 15:04:07 CST 2020 pZxid = 0x200000003 cversion = 1 dataVersion = 1 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 7 numChildren = 1
6.删除节点
delete
可以删除节点。注意,它不会递归删除,所以要删除一个包含子节点的节点,需要先删除所有子节点。
[zk: localhost:2181(CONNECTED) 12] delete /zk_test Node not empty: /zk_test [zk: localhost:2181(CONNECTED) 13] delete /zk_test/child_node1
rmr
命令可以递归删除节点,所以也会删除节点中的所有子节点。
[zk: localhost:2181(CONNECTED) 14] create /test/hello 2323 Node does not exist: /test/hello [zk: localhost:2181(CONNECTED) 15] create /test/hello/hello1 23233 Node does not exist: /test/hello/hello1 [zk: localhost:2181(CONNECTED) 16] rmr /test Node does not exist: /test [zk: localhost:2181(CONNECTED) 17] ls / [test2, zookeeper, test_znode, zk_test, test10000000002]
7.history和redo
history
命令可以列出最近操作的10条命令历史,并给出每个历史命令的编号。redo
命令可以根据历史命令的编号重新调用这些命令。
[zk: localhost:2181(CONNECTED) 18] history 8 - ls2 / 9 - ls / 10 - ls /zk_test 11 - set /zk_test "mydata2" 12 - delete /zk_test 13 - delete /zk_test/child_node1 14 - create /test/hello 2323 15 - create /test/hello/hello1 23233 16 - rmr /test 17 - ls / 18 - history
重新执行编号为13的历史命令:
[zk: localhost:2181(CONNECTED) 19] redo 13 Node does not exist: /zk_test/child_node1
8.connect和close
connect命令用于连接其它ZooKeeper服务器,close用于关闭当前连接。就像ssh到其它服务器,然后exit一样。
[zk: localhost:2181(CONNECTED) 20] connect 192.168.1.220:2181 [zk: 192.168.1.220:2181(CONNECTED) 21] close # 注意下面的ZooKeeper shell提示符中地址和连接状态的变化:
需要注意,当connect到其它服务器后,当前的连接就会断开,当前会话中的临时znode就会被删除。以下是connect到其它服务器时zookeeper.out中相关内容:
2020-03-06 15:10:48,582 [myid:1] - INFO [CommitProcessor:1:ZooKeeperServer@643] - Established session 0x170ae8d1f450000 with negotiated timeout 30000 for client /192.168.1.222:49426 2020-03-06 15:11:52,525 [myid:1] - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:NIOServerCnxn@1008] - Closed socket connection for client /192.168.1.222:49426 which had sessionid 0x170ae8d1f450000
所以,上面执行了close后,不会切换回之前的连接,需要手动再连接。
[zk: 192.168.1.220:2181(CLOSED) 22] close Not connected [zk: 192.168.1.220:2181(CLOSED) 23] close Not connected [zk: 192.168.1.220:2181(CLOSED) 24] ls / Not connected [zk: 192.168.1.220:2181(CLOSED) 25] connect localhost:2181 [zk: localhost:2181(CONNECTED) 26] ls / [zookeeper, test_znode, zk_test, test10000000002]
9.quit
[zk: localhost:2181(CONNECTED) 27] quit Quitting... 2020-03-06 15:22:15,233 [myid:] - INFO [main:ZooKeeper@684] - Session: 0x370ae8d1f490001 closed 2020-03-06 15:22:15,234 [myid:] - INFO [main-EventThread:ClientCnxn$EventThread@519] - EventThread shut down for session: 0x370ae8d1f490001