Summary of common commands in the latest version of Zookeeper (collection of eating ash series)

1. Common commands on the server side

After completing the pseudo-cluster deployment of zookeeper (the deployment tutorial refers to deploying the latest version of zookeeper pseudo-distributed cluster on linux ), you can execute these commands in the bin directory

1. Start the ZK service:

bin/zkServer.sh start

2. Check the ZK service status:

bin/zkServer.sh status

3. Stop ZK service:

bin/zkServer.sh stop

4. Restart the ZK service:

bin/zkServer.sh restart 

5. connect to the server:

zkCli.sh -server 127.0.0.1:2181

2. Common commands of the client

In Linux environment:

zkCli.sh -server 127.0.0.1:2181

After the connection is successful, the system will output the relevant environment and configuration information of ZooKeeper, as follows:

3. Common commands of the client

We can use the help command to view help:

3.1 Create Node

Using the create command, you can create a Zookeeper node, such as

create [-s] [-e] path data acl

Among them, -s or -e specify node characteristics, sequence or temporary node respectively, if not specified, it means persistent node; acl is used for permission control.

1. Create a sequence node

#创建zk-test顺序节点
create -s /zk-test 123

You can see that a string of numbers is added after the created zk-test node to show the difference.

2. Create a temporary node

#创建zk-temp临时节点
 create -e /zk-temp 123

The temporary node will be automatically deleted after the client session ends. Use the quit command to exit the client.

Use the client to connect to the server again, and use the ls / command to view the nodes in the root directory

You can see that the zk-temp temporary node no longer exists in the root directory.

3. Create permanent node

#创建zk-permanent永久节点
create /zk-permanent 123

3.2 Reading Nodes

The commands related to reading include the ls command and the get command. The ls command can list all the child nodes under the node specified by Zookeeper, and can only view all the child nodes of the first level under the specified node; the get command can obtain the data of the node specified by ZK. Data content and attribute information. Its usage is as follows:

ls [-s] [-w] [-R] path
get [-s] [-w] path

To get all the child nodes below the root node, use the ls command.

ls /

If you want to get the data content and attribute information of the root node, use the get -s command.

get -s /

You can also use the ls -s command to view node attribute information

ls -s /

You can see that the number of child nodes is 5.

To get the data content and properties of /zk-permanent, use the following commands:

get -s /zk-permanent

You can see that its data content is 123, and there are other attributes.

3.3 Update Node

Using the set command, you can update the data content of the specified node, the usage is as follows

set [-s] [-v version] path data

Among them, data is the new content to be updated, and version indicates the data version. For example, to update the data of the /zk-permanent node to 456, you can use the following command:

set /zk-permanent 456

Now dataVersion has become 1, indicating that an update has been made.

3.4 Delete Node

Use the delete command to delete the specified node on Zookeeper, the usage is as follows

delete [-v version] path

The version also represents the data version. Use the delete /zk-permanent command to delete the /zk-permanent node

delete /zk-permanent 

As you can see, the /zk-permanent node has been successfully deleted. It is worth noting that if the deleted node has a child node, then the node cannot be deleted. The child node must be deleted first, and then the parent node must be deleted.