Lambda Flashcards
What is AWS Lambda?
A service for runing code without provisioning a server
Services that invoke Lambda Functions Synchronously
"ELB Cognito Lex Alexa API Gateway CloudFront Kinesis Data Firehose Step Functions S3 Batch"
Services that invoke Lambda Functions Asynchronously
"S3 SNS SES CloudFormation CloudWatch Logs CloudWatch Events CodeCommit Config IoT IoT Events CodePipeline"
What may cause a Lambda to return an error message?
Max Memory Used
What may cause a Lambda to time out?
If a connection is unavailable due to access restrictions
What is the Dead-letter Queue feature?
“After a specified number of execution attempts have failed Lambda can forward the unprocessed payload to a DLQ such as an SQS or SNS for logging purposes
DLQs can trigger additonal Lambda functions”
What are the customers responsibilities when using Lambdas?
“Lambda function code
Providing access to AWS resources that trigger the Lambda function
Providing access to AWS resource destinations “
What is the Lambda memory limits per invocation?
memory allocation range min 128 MB/max 3008 MB (64 MB increments)
What is the Lambda timeout limits per invocation?
900 seconds (15 minutes)
What is the Lambda /tmp directory storage limit?
Ephemeral disk capacity (“/tmp” space) 512 MB
What are the Lambda incovation payload limits?
"invocation payloads include request and response 6 MB (synchronous) 256 KB (asynchronous)"
What triggers and destinations are available by default?
“None are available by default
The AWSLambdaBasicExecutionRole grants permission to write to CloudWatch Logs”
Max batch size Lambdas can recieve from resources?
“Streams and DynamoDB 10_000
SQS 10 “
How do you send a constant event from a CloudWatch trigger?
In the CloudWatch event rules configure the input using the option “constant (JSON text)”
What is Lambda Invoke API?
An API used to invoke lambda functions from custom applications