Sorted:

How to prevent duplicate data in high concurrency using Redis?

How to view the status of keepalived?

What are the characteristics of HAProxy?

How to set the maximum connection number in SQL Server?

How to install and deploy Prometheus

What is the method of using Prometheus?

What is the concept of enums in Java?

How to troubleshoot when the keepalive cache pages are not working as expected?

What is the difference between Grafana and Zabbix?

How do you configure HAProxy load balancing?