Instance Types
- General Purpose (T, M): balanced compute, memory, networking.
- Compute Optimized (C): batch processing, HPC, ML inference.
- Memory Optimized (R, X, z): in-memory databases, real-time processing.
- Storage Optimized (I, D, H): high sequential read/write, data warehousing.
- Accelerated Computing (P, G, Inf): GPU, machine learning training.
Pricing Models
- On-Demand: pay per second (Linux) or per hour (Windows). No commitment.
- Reserved (1 or 3 year): up to 72% discount. Standard or Convertible.
- Savings Plans: flexible pricing, commit to $/hr for 1 or 3 years.
- Spot Instances: up to 90% off. Can be interrupted with 2-min notice.
- Dedicated Hosts: physical server. Required for BYOL licensing.
Placement Groups
- Cluster: low latency, single AZ, HPC workloads.
- Spread: max 7 instances per AZ, critical applications.
- Partition: large distributed workloads (Hadoop, Cassandra, Kafka).
Key Features
- User Data: runs scripts at instance launch (runs as root).
- Metadata: http://169.254.169.254/latest/meta-data/
- Hibernation: saves RAM to EBS root volume, faster restart.
- Instance Store: ephemeral, high IOPS, lost on stop/terminate.
- ENI: basic networking. ENA: enhanced networking. EFA: HPC.
Practice EC2 Questions
Put your knowledge to the test with practice questions.