Services - Networking and Content Delivery

Question 1

API Gateway - Characteristics 1

Answer 1

• It helps to create, publish, maintain, monitor, and secure APIs at any scale
• Supports stateful (WebSocket) and stateless (HTTP and REST) APIs
• Have flexible authentication mechanisms such as IAM policies, Lambda authorizer functions, and Cognito user pools
• Make APIs available to your customers by using developer portal, for API Gateway managed APIs and non-API Gateway managed APIs (specified with OpenAPI definitions)
• Provides a dashboard to monitor calls to the services and integrates with CloudWatch, CloudTrail, and WAF

Question 2

API Gateway - Characteristics 2

Answer 2

• Can manage traffic by adding throttling rules based on the number of requests:
• Per API, per-stage. Applied at the API method level for a stage
• AWS throttling limits. Applied across all accounts and clients
• Per-account limits. Applied to all APIs in an account
• Per-client throttling limits. Applied to clients that use API keys, which also are a client identifier
• When there are too many requests it responds to client with “429 Too Many Requests” HTTP code

Question 3

API Gateway - Endpoint types

Answer 3

• Edge-optimized endpoint:
• It reduces latency for requests all around the world
• CloudFront is also used as the public endpoint
• Regional endpoint:
• It reduces latency for requests that originate in the same region
• Can also configure the CDN and protect WAF
• Private endpoint:
• It securely exposes the REST APIs to other services only within the VPC

Question 4

API Gateway - Pricing

Answer 4

• HTTP APIs and REST APIs:
• Pay only for the API calls received and the amount of data transferred out
• When using optional data caching also pay based on the cache size selected
• WebSocket APIs:
• Pay when APIs are used based on number of messages sent / received, and connection minutes

Question 5

API Gateway - REST APIs Features

Answer 5

• Can set up a cache with customizable keys and TTL for each request
• Able to generate client SDKs for many platforms, so can test new APIs and distribute those SDKs to third-party developers
• Also can run multiple versions of the same API so that applications can continue to call previous API versions

Question 6

Global Accelerator - Characteristics 1

Answer 6

• It’s a managed global traffic manager that helps to direct internet traffic from users to your application’s public interfaces or endpoints
• It’s a global service that supports endpoints in multiple AWS Regions
• Pay for each provisioned accelerator. Charged a fixed fee and a incremental charge over Standard Data Transfer rates

Question 7

Global Accelerator - Characteristics 2

Answer 7

• By default, it provides two static IP addresses, as a fixed entry point to your applications, that you associate with your accelerator. So, it’s easy to move your endpoints between regions and AZs
• Static IP addresses will be unassigned only if you delete the respective accelerator(s), not if you disable them
• Propagation of changes takes seconds. The opposite to DNS-based client devices and internet resolvers that cache DNS answers for long periods of time

Question 8

Global Accelerator - Standard accelerator

Answer 8

• Routes client traffic across regional endpoints based on client location, endpoint health, and configurable policies
• Endpoints can be ALBs, NLBs, EC2 instances, or EIP addresses
• Also allows to shift client traffic across endpoints based on controls such as traffic dials (percentage traffic of the endpoint) and endpoint weights
• Can use IPv4 addresses from your own IP address ranges as entry points

Question 9

Global Accelerator - Custom routing accelerator

Answer 9

• Works well where you want to use custom application logic to direct users to a specific destination and port among many, while still gaining the benefits of Global Accelerator
• Only support VPC subnet endpoint types as entry points

Question 10

Global Accelerator - Components

Answer 10

• Static IP addresses and DNS name
• Accelerator
• Network zone: services the IP addresses from a unique IP subnet. Similar to an AZ, it’s an isolated unit with its own set of physical infrastructure
• Listener: processes inbound connections from clients to Global Accelerator, based on the port and protocol configured
• Endpoint: the resource where traffic is directed
• Endpoint group: associated with one Region. Includes one or more endpoints in the Region. Using Standard accelerator can use the traffic dial