M10: Automatic Scaling and monitoring

Question 1

Elastic load balancing

Answer 1

Distributes incoming application or network traffic across multiple targets in a single availability zone or across multiple availability zones
Offers several monitoring tools for continuous monitoring and logging for auditing and analytics

Question 2

Three types of elastic load balancing

Answer 2

1. Application load balancer: level 7, ideal for HTTP/S traffic including containers, ensures latest SSL/TLS used.
2. Network load balancer: layer 4, transport, routing connections to targets based on IP protocol data
3. Classic load balancer: load balancing across multiple EC2 instances, older.

Question 3

Configuring load balancer

Answer 3

1. Listener

2. Optional health checks

Question 4

Configuring load balancer types

Answer 4

Application and network load balancers register targets in target groups and route traffic to target groups
Classic, register instances with load balancer

Question 5

Reasons to use load balancer

Answer 5

1. Achieve high availability and better fault tolerance for your application
2. Automatically load balance your containerised applications
3. Automatically scale your applications
4. Use elastic load balancing in your VPC
5. Enable hybrid load balancing
6. Invoking lambda functions over HTTP/S

Question 6

Amazon CloudWatch

Answer 6

Monitoring and observability service

Can respond to changes and take corrective action ss necessary

Question 7

CloudWatch alarm

Answer 7

Single metric
Maths expression based on CloudWatch metrics
Static threshold
Anomaly detection
Metric maths expression

Question 8

Specification needed for a static threshold alarm

Answer 8

1. Namespace: metric wanted, eg EC2
2. Metric: variable to measure
3. Statistic: average, sum, percentile…
4. Period: evaluation period
5. Conditions: metric greater, greater equal…
6. Additional configuration information: number of data points that need to be breached
7. Actions: send notification to SNS topic, perform auto scaling, EC2 action

Question 9

EC2 auto scaling

Answer 9

Maintains application availability and enables the automatic addition or removal of EC2 instances according to conditions you define

Question 10

Ways to use auto scaling

Answer 10

EC2 Instances can be added / deleted:

• manually
• on a schedule
• in response to demand
• in combination with auto scaling
• dynamic and predictive scaling can be used together to scale faster

Question 11

Auto scaling group

Answer 11

Collection of EC2 instances treated as a logical grouping for purposes of automatic scaling and management
Minimum, desired and maximum size

Question 12

Launch configuration

Answer 12

Instance configuration template

Question 13

Implement dynamic scaling

Answer 13

EC2 auto scaling, Amazon CloudWatch and elastic load balancing

Question 14

AWS auto scaling

Answer 14

Separate service that monitors your application, automatically adjusting for the following resources :

• amazon EC2 instances and spot fleets
• amazon ECS tasks
• amazon DynamoDB tables and indexes
• amazon aurora replicas