Compute & Load Balancing

Question 1

EC2 R Instance Types

Answer 1

Applications that need a lot of RAM (e.g in memory cache)

Question 2

EC2 C Instance Types

Answer 2

Applications that need good CPU (e.g databases or compute)

Question 3

EC2 M Instance Types

Answer 3

Applications that are balanced (e.g general or web apps)

Question 4

EC2 I Instance Types

Answer 4

Applications that need good local I/O (e.g databases)

Question 5

EC2 G Instance Types

Answer 5

Applcations that need a GPU (e.g video rendering or machine learning)

Question 6

EC2 T2/T3 Instance Types

Answer 6

Burstable instances

Question 7

EC2 Cluster Placement Strategy

Answer 7

Clusters instances into a low latency group in a single AZ
* Pro: Low latency
* Con: If the rack fails, all instances fail

Question 8

EC2 Spread Placement Strategy

Answer 8

Spreads instances across underlying hardware
* Pro: span across AZs, reduce risk of simultaneous failure
* Con: Limited to 7 instances per group per AZ

Question 9

EC2 Partition Placement Strategy

Answer 9

Spreads instances across logical partitions such that groups of instances in one partition do not share the underlying hardware with groups in different partitions

Question 10

How to move instances between placement groups

Answer 10

1. Stop the instance
2. Use the CLI to modify the placement
3. Start the instance

Question 11

EC2 Instance Launch Type

Answer 11

• On demand: short workload, predictable pricing, reliable
• Spot: short workload, cheap, can lose instances
• Reserved: minimum 1 year
• Dedicated: no other customers will share hardware
• Dedicated host: book an entire physical server and control instance placement

Question 12

EC2 Graviton

Answer 12

Family of processors designed to deliver the best price performance for your cloud workloads

Question 13

EC2 Enhanced Networking

Answer 13

Higher bandwidth, higher pps, lower latency
* Elastic Network Adapter (ENA) up to 100 Gbps
* Legacy: Intel 82599 VF

Question 14

Elastic Fabric Adapter

Answer 14

Improved Elastic Network Adapter, only works for Linux. Great for inter node communication, tightly coupled workloads.

Question 15

Auto Scaling Groups

Dynamic Scaling Policies

Answer 15

1. Target tracking scaling: Increase and decrease the capacity based on a CloudWatch metric and a target value
2. Simple step scaling: Increase and decrease capacity based on a set of scaling adjustments
3. Scheduled actions

Question 16

Auto Scaling Groups

Predictive Scaling

Answer 16

Continously forecast load and schedule scaling ahead