2-Serverless Flashcards
How is Lambda charged?
You pay per request and by duration (rounded up to 100ms)
Duration pricing is based on memory allocation
How can Lambda versions be managed?
Once a version is created, it is immutable.
Therefore, create aliases and change the version that they reference
How is the most recent Lambda version denoted?
It automatically has the $LATEST alias applied to it
What is the ARN for a Lambda function?
arn:aws:lambda:[region]:[account]:function:[name]:[version/alias]
How can traffic to Lambda functions be split?
Based on aliases. Note that traffic can’t be split on the $LATEST alias
What is a key requirement for custom API Gateway domains?
They must have an SSL/TLS certificate defined in the AWS Certificate Manager
What protocols does API Gateway support?
It’s usually used with REST but can be configured as a SOAP passthrough
In the context of API Gateway, how does CORS work?
Setting a CORS policy defines the result of the OPTIONS call the client makes when considering whether to accept resources from that API
How can API Gateways be automatically configured?
The API Gateway Import feature allows Swagger v2 files to be imported
What are the default limits for API Gateway
A maximum of 10,000 requests per second to a single Gateway
Not more than 5,000 concurrent requests across a whole account
What happens if the API Gateway throttling limits are exceeded?
It returns Error 429: Too many requests
What are Step Functions?
A service to coordinate components in a serverless application. It retries if any errors occur
Three step types are supported: sequential, branching and parallel
What is Amazon X-Ray?
A service that collects data about an application and the AWS services / web services it uses
It integrates with ELB, Lambda, API Gateway, EC2 and Elastic Beanstalk
