What methods can be used to configure and manage server groups to ensure high availability and scalability?

To ensure high availability and scalability of servers, the following approaches are usually used:

1. Load Balancing — distributing incoming traffic among multiple servers to avoid overload of any single one. Hardware or software load balancers (e.g., Nginx, HAProxy) are used.

2. Clustering — combining multiple servers into a cluster that operates as a single entity. If one node fails, others continue to operate.

3. Auto Scaling — dynamically adding or removing servers depending on the load.

4. Replication and Fault Tolerance — duplicating data and services across multiple servers to prevent data loss and ensure continuous operation.

5. Container Orchestration — using systems like Kubernetes to manage groups of containers, automate scaling, and recovery.

Example of configuring a load balancer on Nginx for multiple servers:

upstream backend {
    server backend1.example.com;
    server backend2.example.com;
}

server {
    listen 80;
    location / {
        proxy_pass http://backend;
    }
}

Thus, requests will be distributed between backend1 and backend2.