Using ZooKeeper from Scratch¶
ZooKeeper is an open-source, highly reliable, and distributed consistency coordination service. ZooKeeper is designed to solve the problem that data consistency cannot be ensured for complex and error-prone distributed systems. There is no need to develop dedicated collaborative applications, which is suitable for high availability services to ensure data consistency.
Background Information¶
Before using the client, you need to download and update the client configuration file on all clients except the client of the active management node.
Procedure¶
Download the client configuration file.
Log in to FusionInsight Manager. For details, see. Accessing FusionInsight Manager
Choose Cluster > Name of the desired cluster > Dashboard > More > Download Client.
Download the cluster client.
Set Select Client Type to Configuration Files Only, select a platform type, and click OK to generate the client configuration file which is then saved in the /tmp/FusionInsight-Client/ directory on the active management node by default.
Log in to the active management node of Manager.
Log in to any node where Manager is deployed as user root.
Run the following command to identify the active and standby nodes:
sh ${BIGDATA_HOME}/om-server/om/sbin/status-oms.sh
In the command output, the value of HAActive for the active management node is active, and that for the standby management node is standby. In the following example, node-master1 is the active management node, and node-master2 is the standby management node.
HAMode double NodeName HostName HAVersion StartTime HAActive HAAllResOK HARunPhase 192-168-0-30 node-master1 V100R001C01 2020-05-01 23:43:02 active normal Actived 192-168-0-24 node-master2 V100R001C01 2020-05-01 07:14:02 standby normal Deactived
Log in to the primary management node as user root and run the following command to switch to user omm:
sudo su - omm
Run the following command to go to the client installation directory, for example, /opt/client.
cd /opt/client
Run the following command to update the client configuration for the active management node.
sh refreshConfig.sh /opt/client Full path of the client configuration file package
For example, run the following command:
sh refreshConfig.sh /opt/client /tmp/FusionInsight-Client/FusionInsight_Cluster_1_Services_Client.tar
If the following information is displayed, the configurations have been updated successfully:
ReFresh components client config is complete. Succeed to refresh components client config.
Use the client on a Master node.
On the active management node where the client is updated, for example, node 192-168-0-30, run the following command to go to the client directory:
cd /opt/client
Run the following command to configure environment variables:
source bigdata_env
If Kerberos authentication has been enabled for the current cluster, run the following command to authenticate the current user. If Kerberos authentication is disabled for the current cluster, skip this step:
kinit MRS cluster user
Example: kinit zookeeperuser.
Run the following Zookeeper client command:
zkCli.sh -server <zookeeper installation node IP>:<port>
Example: zkCli.sh -server node-master1DGhZ:2181
Run the ZooKeeper client command.
Create a ZNode.
create /test
View ZNode information.
ls /
Write data to the ZNode.
set /test "zookeeper test"
View the data written to the ZNode.
get /test
Delete the created ZNode.
delete /test