Phase Verbs / Action Phrases
| Phrase | Meaning |
|---|---|
| optimize (for) | design specifically to be most efficient at a particular task |
| compare (instances) | evaluate different types against each other |
| balance (compute/memory/network) | have equal emphasis on multiple dimensions |
| process (large data sets) | handle/analyze big amounts of data |
Technical Vocabulary
| Term | Definition |
|---|---|
| Instance type | The combination of CPU, RAM, storage, and network capacity of an EC2 virtual machine |
| Instance class | The category letter: m=general, c=compute, r=memory/RAM, i/d/h=storage |
| Generation | Version number of the instance family (e.g., m5 is 5th generation) |
| Size | How large the instance is within its class (e.g., 2xlarge) |
| vCPU | Virtual CPU — shares a physical CPU core |
| OLTP | Online Transaction Processing — database workload with many rapid small transactions |
| HPC | High Performance Computing — scientific/engineering calculations requiring massive CPU |
| In-memory database | Database that stores data in RAM for ultra-fast access (e.g., Redis, ElastiCache) |
| Data warehouse | Storage optimized for analytical queries on large historical data sets |
| Distributed file system | Storage spread across many nodes, accessed as a single filesystem |
Key Concepts
Instance Type Naming Convention
Example: m5.2xlarge
m= instance class (general purpose)5= generation (5th)2xlarge= size
EC2 Instance Families
| Family | Letter | Use Cases |
|---|---|---|
| General Purpose | t, m | Web servers, code repos, balanced workloads |
| Compute Optimized | c | Batch processing, media transcoding, ML, gaming servers, HPC |
| Memory Optimized | r, x1, high mem, z1 | In-memory DBs, ElastiCache, real-time big data analytics |
| Storage Optimized | i, d, h1 | OLTP, NoSQL DBs, Redis cache, data warehousing, distributed file systems |
| Accelerated Computing | (GPU types) | ML inference, graphics rendering |
Example Comparison
| Instance | vCPU | RAM | Notes |
|---|---|---|---|
| t2.micro | 1 | 1 GB | Free tier eligible; used in this course |
| r5.16xlarge | 16 | 512 GB | Memory optimized |
| c5d.4xlarge | 16 | 32 GB | Compute optimized, more CPU emphasis |
Useful Reference
ec2instances.info— compare all EC2 instance types with pricing
Exam Tips
- Know the 5 instance families: General Purpose, Compute (C), Memory (R/X), Storage (I/D/H), Accelerated Computing
- T2.micro = general purpose, free tier eligible
- General purpose = balanced compute/memory/networking
- Compute optimized = high CPU (C-series)
- Memory optimized = high RAM (R-series — R = RAM)
- Storage optimized = high local disk I/O (I/D/H series)