Connect to ZooKeeper

You can connect to ZooKeeper from the same server where it is installed with the ZooKeeper client tool. Execute the following command:

$ zkCli.sh

You should see an output similar to this:

You can run the following example to see how to add new data to ZooKeeper, recover it, and delete the created registries:

• Use the list command to see the data stored in the instance:

    $ ls /
    [zookeeper]
  

• Create a new directory (in this example, test directory which includes the string mydata) using the create / command. This creates a new znode and associates the string “my_data” with the node. You should see:

    $ create /test mydata
    Created /test
  

• Use the list command again to see how the directory looks like now:

    $ ls /
    [zookeeper, test]
  

• Check the information associated to the new node by using the get / command:

    $ get /test
    mydata
    cZxid = 0x23
    ctime = Fri Jun 01 14:43:23 UTC 2018
    mZxid = 0x23
    mtime = Fri Jun 01 14:43:23 UTC 2018
    pZxid = 0x23
    cversion = 0
    dataVersion = 0
    aclVersion = 0
    ephemeralOwner = 0x0
    dataLength = 6
    numChildren = 0
  

• Change the data associated to the test node using the set / command:

    $ set /test apache
    cZxid = 0x23
    ctime = Fri Jun 01 14:43:23 UTC 2018
    mZxid = 0x24
    mtime = Fri Jun 01 14:51:07 UTC 2018
    pZxid = 0x23
    cversion = 0
    dataVersion = 1
    aclVersion = 0
    ephemeralOwner = 0x0
    dataLength = 6
    numChildren = 0
  

  Run again the get / command to check that the data has been changed from mydata to apache:

    $ get /test
    apache
    cZxid = 0x23
    ctime = Fri Jun 01 14:43:23 UTC 2018
    mZxid = 0x24
    mtime = Fri Jun 01 14:51:07 UTC 2018
    pZxid = 0x23
    cversion = 0
    dataVersion = 1
    aclVersion = 0
    ephemeralOwner = 0x0
    dataLength = 6
    numChildren = 0
  

• Delete the node with the delete / command:

    $ delete /test
  

  If you execute again the ls / command you should see only the [zookeeper] node.