Dealing with Size Limits in AWS Lambda

Size Limits in Zip Based Lambda Functions

You need to be aware of multiple size limits for Lambda zip based functions:

• 50 MB for compressed deployment package of a function,

• 250 MB after a function is unzipped,

• 75 GB for all Lambda functions that have been deployed in a region,

• 10 MB when you are uploading a function through Console UI

Some Possible Solutions

The possible workarounds are:

• Reduce the function package size,

• Use container image or layers based functions,

• Use some other AWS product like ECS,

• Store large libraries and files in a S3 bucket and download them during runtime.

Reducing function package size

• AWS SDK libraries are already in place, upload only your own code and third party libraries.

• Carefully selecting which libraries to include and excluding unnecessary dependencies.

• Package Lambda functions individually using the Individually: true flag.

• Use serverless-webpack to reduce the package size.

• Store large binaries or files in the package in S3 and download them during runtime.

• If you're using Python libraries, you can get rid of botocore, boto3 as they are already present in AWS's lambdas functions.

Keep in Mind

• Lambda function has a maximum runtime of 15 minutes; downloading large files will take time away the time from your functions runtime.

• You can configure ephemeral storage (/tmp) between 512 MB and 10 GB.