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ec2

Amazon EC2 Overview

  • Definition: Elastic Compute Cloud (EC2) is a web service that provides scalable compute capacity in the cloud.
  • Key Concepts:
    • Instances: Virtual servers running in AWS.
    • AMIs (Amazon Machine Images): Templates for instance OS and software.
    • Instance Types: Variations in CPU, memory, storage, and networking.
  • Use Cases: Web hosting, app servers, batch processing, machine learning.

1. EC2 Instance Types

EC2 offers families optimized for different workloads, critical for performance and cost optimization.

General Purpose (e.g., T3, M5)

  • Purpose: Balanced compute, memory, and networking.
  • Examples: T3 (burstable), M5 (consistent performance).
  • Use Case: Web servers, small databases.

Compute Optimized (e.g., C5)

  • Purpose: High-performance CPU.
  • Features: Ideal for compute-intensive tasks.
  • Use Case: Gaming servers, scientific modeling.

Memory Optimized (e.g., R5)

  • Purpose: Large memory capacity.
  • Features: High memory-to-CPU ratio.
  • Use Case: In-memory databases (e.g., Redis), big data analytics.

Storage Optimized (e.g., I3, D2)

  • Purpose: High I/O or dense storage.
  • Features: NVMe SSDs (I3) or HDDs (D2).
  • Use Case: NoSQL databases, data warehousing.

Accelerated Computing (e.g., G4, P3)

  • Purpose: GPU/FPGA acceleration.
  • Features: High-performance graphics or ML.
  • Use Case: Machine learning, video rendering.

Key Notes:

  • Performance: Match instance type to workload (e.g., C5 for CPU-bound apps).
  • Exam Tip: Memorize family purposes (e.g., ā€œCā€ for compute).

2. EC2 Storage Options

EC2 integrates with various storage types for resilience and performance.

Elastic Block Store (EBS)

  • Purpose: Persistent block storage for EC2.
  • Types:
    • gp3: General-purpose SSD (cost-effective, configurable IOPS).
    • gp2: General-purpose SSD (older, IOPS tied to size).
    • io1/io2: Provisioned IOPS SSD (high performance).
    • st1: Throughput-optimized HDD (big data).
    • sc1: Cold HDD (infrequent access).
  • Features: Snapshots, encryption, Multi-Attach (io1/io2).
  • Use Case: Databases, boot volumes.

Instance Store

  • Purpose: Temporary block storage.
  • Features: Physically attached to host, lost on stop/termination.
  • Use Case: Caches, scratch data.
  • Note: Ephemeral, not resilient.

EFS (Elastic File System)

  • Purpose: Shared file storage for multiple EC2 instances.
  • Features: NFS protocol, scales automatically.
  • Use Case: Content management, shared workloads.

Key Notes:

  • Resilience: EBS snapshots for backups, EFS for multi-instance access.
  • Exam Tip: Compare EBS vs. Instance Store durability.

3. EC2 Security

Security is a key focus for SAA-C03.

Security Groups

  • Purpose: Virtual firewall for instances.
  • Features: Stateful, allow rules only (no deny).
  • Example: Allow port 80 from 0.0.0.0/0 for web traffic.
  • Use Case: Control inbound/outbound traffic.

IAM Roles

  • Purpose: Grant EC2 instances permissions.
  • Features: Attach role to instance, no static credentials.
  • Use Case: Allow EC2 to access S3 buckets.

Key Pairs

  • Purpose: SSH access to instances.
  • Features: Public key stored by AWS, private key with user.
  • Note: Lost private key = no access.

Key Notes:

  • Secure Design: Use least privilege in IAM roles, restrict security groups.
  • Exam Tip: Practice security group rules for scenarios.

4. EC2 Resilience Features

Resilience ensures high availability and fault tolerance.

Auto Scaling

  • Purpose: Automatically adjust instance count.
  • Components:
    • Launch Template: Defines instance config (AMI, type).
    • Scaling Policies: Target tracking (e.g., CPU at 50%), step scaling.
  • Use Case: Handle traffic spikes.

Elastic Load Balancing (ELB)

  • Types:
    • Application Load Balancer (ALB): HTTP/HTTPS, path-based routing.
    • Network Load Balancer (NLB): TCP/UDP, low latency.
    • Classic Load Balancer: Legacy.
  • Features: Distributes traffic across instances.
  • Use Case: High availability web apps.

Placement Groups

  • Types:
    • Cluster: Low-latency group in single AZ.
    • Spread: Instances across distinct hardware (max 7 per AZ).
    • Partition: Multiple partitions per AZ (e.g., Hadoop).
  • Use Case: Optimize performance or resilience.

Key Notes:

  • Resilience: Auto Scaling + ELB for multi-AZ deployments.
  • Exam Tip: Know when to use Spread vs. Cluster.

5. EC2 Performance Features

High-performing architectures leverage EC2 optimizations.

Enhanced Networking

  • Purpose: Higher bandwidth, lower latency.
  • Options: Elastic Network Adapter (ENA), Elastic Fabric Adapter (EFA).
  • Use Case: HPC, big data.

Instance Type Selection

  • Purpose: Match workload to resources.
  • Example: C5 for CPU-heavy tasks, R5 for memory-intensive.

EBS Optimization

  • Purpose: Improve I/O performance.
  • Features: Enabled by default on many instances.
  • Use Case: Databases with high IOPS.

Key Notes:

  • Performance: Enhanced Networking + right instance type.
  • Exam Tip: Identify workload needs in scenarios.

6. EC2 Cost Optimization

Cost optimization is critical for SAA-C03.

Pricing Models

  • On-Demand: Pay per hour/second, no commitment.
  • Reserved Instances (RI): 1- or 3-year commitment, up to 72% savings.
  • Spot Instances: Bid on unused capacity, up to 90% savings.
  • Savings Plans: Flexible RI alternative.
  • Dedicated Hosts: Physical server, per-host billing.

Spot Fleet

  • Purpose: Manage multiple Spot Instances.
  • Features: Diversifies across instance types/AZs.
  • Use Case: Batch processing.

Auto Scaling

  • Purpose: Scale down to reduce costs.
  • Use Case: Shut down unused instances overnight.

Key Notes:

  • Cost Savings: Spot for interruptible workloads, RI for steady-state.
  • Exam Tip: Calculate costs for mixed pricing scenarios.

7. EC2 Networking

Networking integrates EC2 with VPCs.

Elastic Network Interface (ENI)

  • Purpose: Virtual NIC for instances.
  • Features: Attach multiple ENIs, move between instances.
  • Use Case: Failover, multi-IP setups.

Elastic IP (EIP)

  • Purpose: Static public IP.
  • Features: Reassignable, no charge when attached.
  • Use Case: Persistent public access.

VPC Integration

  • Purpose: Place EC2 in private/public subnets.
  • Features: Route tables, NAT Gateway for outbound.
  • Use Case: Secure app tier in private subnet.

Key Notes:

  • Networking: ENI for flexibility, EIP for consistency.
  • Exam Tip: Design VPC with EC2 placement.

8. EC2 Use Cases

Understand practical applications.

Web Hosting

  • Setup: EC2 + ALB + Auto Scaling.
  • Features: Scalable, resilient web servers.

Batch Processing

  • Setup: Spot Instances + SQS.
  • Features: Cost-effective, fault-tolerant.

High-Performance Computing (HPC)

  • Setup: Cluster placement group + C5 instances.
  • Features: Low-latency, high CPU.

Key Notes:

  • Versatility: EC2 fits many roles with proper config.
  • Exam Tip: Match use case to features.

Quick Reference Table

Feature Purpose Key Detail Exam Relevance
Instance Types Workload optimization T3, C5, R5, etc. Performance, Cost
EBS Persistent storage gp3, io2, snapshots Resilience, Performance
Security Groups Traffic control Stateful, allow-only Security
Auto Scaling Dynamic scaling Launch templates, policies Resilience, Cost
ELB Load distribution ALB, NLB Resilience, Performance
Pricing Models Cost management Spot, RI, On-Demand Cost Optimization
Enhanced Networking Better performance ENA, EFA Performance
ENI/EIP Networking flexibility Multiple IPs, static addressing Networking, Resilience