How does keepalived achieve high availability?
Keepalived is a tool used to achieve high availability by monitoring the health status of servers and automatically switching to a backup server when the main server fails. The steps to implement high availability using Keepalived are as follows:
- Install Keepalived: Install the Keepalived package on both the primary server and the backup server.
- Set up Keepalived: Modify the configuration file of Keepalived, typically located at /etc/keepalived/keepalived.conf. This file contains information such as the virtual IP address, the relationship between the master and backup servers, and monitoring scripts.
- Set up monitoring scripts: You can write custom monitoring scripts to check the health status of the server, such as using the ping command to detect network connectivity, and using HTTP requests to check if the website is available.
- Start Keepalived: Launch the Keepalived service on both the primary server and the backup server, ensuring that it starts automatically.
- Test high availability: simulate a failure of the main server to observe if Keepalived can automatically switch to the backup server and if the virtual IP address can function properly.
It should be noted that the configuration and usage of Keepalived also involve other details and parameters, which can be adjusted and configured according to specific needs and environments. Additionally, Keepalived can also be used in conjunction with other tools such as Nginx, HAProxy, etc. to achieve more powerful high availability solutions.
