Amazon EC2 Explained: Instances, EBS, Security Groups, Auto Scaling, and Load Balancing

Amazon EC2 Explained: Instances, EBS, Security Groups, Auto Scaling, and Load Balancing

Amazon EC2 gives you virtual machines with direct control over the operating system, runtime, networking, and attached storage. That flexibility is useful—but it also means you own more infrastructure operations than with Fargate or Lambda.

Choose Instances by Workload

EC2 instance families are optimized for different CPU, memory, storage, networking, or accelerator profiles. Benchmark the application rather than choosing a larger generic VM by habit.

Use Launch Templates

Launch Templates define repeatable instance configuration such as AMI, instance type, security groups, IAM profile, storage, and metadata settings. They are the modern basis for Auto Scaling; legacy Launch Configurations no longer support newer EC2 capabilities and are unavailable to newer accounts.

Version templates so infrastructure changes are reviewable and rollbackable.

Treat Instances as Replaceable

Avoid manually SSHing into production machines to create unique “pet” servers.

Prefer:

build AMI/image or bootstrap deterministically
→ launch instance
→ health check
→ replace old instance

Keep durable application data in RDS, S3, EBS with an explicit persistence design, or another durable service.

Security

• Restrict inbound traffic with security groups.
• Prefer IAM instance roles over static AWS access keys.
• Require IMDSv2 where appropriate to strengthen access to instance metadata credentials.
• Keep backend instances in private subnets when direct public access is unnecessary.
• Patch AMIs/OS regularly and replace instances through automation.

Scale With ALB + Auto Scaling

For stateless web backends, use an Auto Scaling Group across multiple Availability Zones behind a load balancer.

Health checks should remove broken instances and scaling policies should reflect real workload pressure. Remember that adding EC2 instances also adds database/API connection pressure downstream.

EBS and Instance Storage

EBS provides persistent block storage that can survive instance replacement according to volume lifecycle settings. Instance-store disks are ephemeral.

Neither is a substitute for application-aware backups.

Final Takeaway

EC2 is the right AWS compute primitive when you need VM-level control. Use Launch Templates, immutable replacement, instance roles, private networking, Auto Scaling, and multiple Availability Zones so that one manually configured server does not become your entire production architecture.

References

• Amazon EC2 Documentation
• EC2 Launch Templates
• EC2 Auto Scaling