EC2 instance types

EC2 Instance Types: Complete Guide for AWS Cloud Practitioner Exam

Why EC2 Instance Types Are Important

EC2 instance types are fundamental to AWS because they determine the computing power, memory, storage, and networking capacity available to your applications. Choosing the right instance type directly impacts your application's performance and your AWS costs. Understanding instance types is essential for the Cloud Practitioner exam as it demonstrates your knowledge of AWS compute services.

What Are EC2 Instance Types?

EC2 instance types are pre-configured virtual server templates that offer different combinations of CPU, memory, storage, and networking resources. AWS organizes these into instance families, each optimized for specific use cases.

Instance Family Categories:

General Purpose (T, M series)
- Balanced compute, memory, and networking
- Ideal for web servers, small databases, development environments
- T3, T3a, M5, M6i are common examples

Compute Optimized (C series)
- High-performance processors
- Best for batch processing, gaming servers, scientific modeling, machine learning inference
- C5, C6i are common examples

Memory Optimized (R, X, Z series)
- Fast performance for memory-intensive workloads
- Ideal for in-memory databases, real-time big data analytics
- R5, R6i, X1, X2idn are common examples

Storage Optimized (I, D, H series)
- High sequential read and write access to large datasets
- Best for data warehousing, distributed file systems
- I3, D2, H1 are common examples

Accelerated Computing (P, G, Inf, Trn series)
- Hardware accelerators or co-processors
- Used for machine learning training, graphics rendering, video encoding
- P4, G4, Inf1 are common examples

How Instance Naming Works

Instance names follow a pattern: family + generation + size

Example: m5.large
- m = General purpose family
- 5 = Fifth generation
- large = Size (determines CPU and memory)

Sizes range from nano, micro, small, medium, large, xlarge, to metal.

How to Choose the Right Instance Type

1. Analyze your workload requirements
2. Consider CPU vs memory vs storage needs
3. Evaluate networking requirements
4. Start with general purpose and adjust based on performance
5. Use AWS Compute Optimizer for recommendations

Exam Tips: Answering Questions on EC2 Instance Types

Key Associations to Remember:

- Web servers, balanced workloads → General Purpose (T, M)
- High-performance computing, batch processing → Compute Optimized (C)
- In-memory databases, caching → Memory Optimized (R, X)
- Big data, data warehouses, log processing → Storage Optimized (I, D, H)
- Machine learning, GPU workloads → Accelerated Computing (P, G)

Common Exam Scenarios:

1. When a question mentions cost-effective and variable workloads, think T-series with burstable performance
2. Questions about SAP HANA or in-memory databases point to Memory Optimized
3. Scientific calculations or modeling suggest Compute Optimized
4. Video transcoding or 3D rendering indicates Accelerated Computing

Remember These Facts:

- Instance types can be changed after launch (instance must be stopped)
- Newer generations typically offer better price-performance
- T-series instances use CPU credits for bursting
- The exam tests conceptual understanding, not memorization of specific instance specs

Practice Question Approach:

1. Identify the workload type mentioned in the question
2. Match it to the appropriate instance family
3. Eliminate answers that mention instance types not suited for that workload
4. Consider cost optimization if mentioned in the question