How to troubleshoot Zookeeper on CentOS

Follow these steps to troubleshoot Zookeeper on CentOS:

Log Analysis

• View log files : Zookeeper's log files are usually located in /var/log/zookeeper/zookeeper.out. Use the cat command to view the content of the log file and analyze the error message or exception stack.
• Log level settings : You can configure the zoo.cfg file to set the log level to obtain more detailed debugging information.

Four-character command

• Use the four-word command provided by Zookeeper to monitor cluster status and debug problems. For example:
  • stat: Displays the running status of the server.
  • ruok: Check if Zookeeper is running.
  • mntr: Provides detailed operation information of the cluster.
  • cons: Displays details of client connection.

Node fault handling

• Check node downtime : Check log files and analyze whether there are any abnormalities before node downtime. Confirm whether the server resources (such as memory, CPU, disk) are sufficient.
• Network Problem : Use netstat and ping tools to check network connectivity and latency.
• Frequent switching of leaders : Check the performance and network status of the leader node to see if there is any situation in the log where the follower cannot be synchronized.

Port occupation check

• If you find that the Zookeeper port is occupied, you can use the netstat command to view port usage and use the ps command to view process details of the occupied port.

Service status check

• Use the systemctl command to check the status of the Zookeeper service, start the service, and set the service to automatically start when the system starts.

Configuration file check

• Check Zookeeper's configuration file /etc/zookeeper/conf/zoo.cfg to ensure that all parameters are set correctly, such as server address, data directory path, client connection port, etc.

System resource inspection

• Check the node's CPU, memory, and disk usage to determine whether there is a problem of insufficient resources.

Version and environment checks

• Make sure the Zookeeper version is compatible with the JDK version and check whether the system environment variables are set correctly.

Through the above steps, Zookeeper troubleshooting can be effectively carried out. If the problem persists, it is recommended to check out Zookeeper's official documentation or seek community help.

The above is the detailed content of How to troubleshoot Zookeeper on CentOS. For more information, please follow other related articles on the PHP Chinese website!