What is a Lambda Concurrent Execution Limit? And what is the limit?
- It’s a limit on the number of concurrent executions across all functions in a given region per account.
- The default limit is at 1.000
What error will I see if I exceed the limit?
- “TooManyRequestException”
- HTTP Status Code 429
Can the concurrent execution limit be increased?
Yes, but you will have to contact AWS Support.
In Lambda, what is Reserved concurrency?
It’s a set number of executions which are reserved for a certain function. It also acts as a limit for that function.
If you are using an unqualified ARN for Lambda, which version will be used? (i.e. no alias or version in the ARN)
$LATEST
By default, a Lambda function cannot access resources inside a private VPC. What do we need to set up to change this?
- Provide VPC config information to the function
- Private subnet ID
- Security group ID (with required access)
How does it work when a Lambda function sets up config to access resources within a private VPC?
- Private subnet ID and Security group ID is given to the function
- Lambda uses the VPC information to set up Elastic Network interfaces (ENIs) using an IP from the private subnet CIDR range
- The security group needs to allow your function to access resources in VPC
Triggers?
- API Gateway
- AWS IoT
- Alexa Skills Kit
- Alexa Smart Home
- Application Load Balancer
- CloudFront
- CloudWatch logs
- CodeCommit
- Cognito Sync trigger
- DynamoDB
- EventBridge (CloudWatch Events)
- Kinesis
- S3
- SNS
- SQS
What 7 languages is supported by Lambda?
- Java
- Python
- Go
- Node.js
- C#
- PowerShell
- Ruby
Can Lambda functions do things globally?
Yes.
What is the maximum timeout for a Lambda function?
15 minutes
What is the default timeout on a Lambda function?
3 seconds
