⚡️ Serverless Plugin for DynamoDB Auto Scaling
With this plugin for serverless, you can enable DynamoDB Auto Scaling for tables and Global Secondary Indexes easily in your serverless.yml configuration file. The plugin supports multiple tables and indexes, as well as separate configuration for read and write capacities using Amazon's native DynamoDB Auto Scaling.
Usage
Add the NPM package to your project:
# Via yarn
$ yarn add serverless-dynamodb-autoscaling
# Via npm
$ npm install serverless-dynamodb-autoscaling
Add the plugin to your serverless.yml:
plugins:
- serverless-dynamodb-autoscaling
Configuration
Configure DynamoDB Auto Scaling in serverless.yml with references to your DynamoDB CloudFormation resources for the table property. The index configuration is optional to apply Auto Scaling Global Secondary Index.
custom:
capacities:
- table: CustomTable # DynamoDB Resource
index: # List or single index name
- custom-index-name
read:
minimum: 5 # Minimum read capacity
maximum: 1000 # Maximum read capacity
usage: 0.75 # Targeted usage percentage
write:
minimum: 40 # Minimum write capacity
maximum: 200 # Maximum write capacity
usage: 0.5 # Targeted usage percentage
That's it! With the next deployment, serverless will add a CloudFormation configuration to enable Auto Scaling for the DynamoDB resources CustomTable and its Global Secondary Index called custom-index-name.
You must provide at least a configuration for read or write to enable Auto Scaling!
Defaults
maximum: 200
minimum: 5
usage: 0.75
Index
If you only want to enable Auto Scaling for the index, use indexOnly: true to skip Auto Scaling for the general DynamoDB table.
API Throtteling
CloudWatch has very strict API rate limits! If you plan to configure Auto Scaling for multiple DynamoDB tables or Global Secondary Indexes, request an increase of the rate limits first! Otherwise, you might run into an error like this:
An error occurred while provisioning your stack: XYZ - Unable to create alarms for scaling policy XYZ due to reason:
Rate exceeded (Service: AmazonCloudWatch; Status Code: 400; Error Code: Throttling; Request ID: XYZ).
Breaking Changes
There have been multiple breaking changes regarding CloudFormation resource names in the past. If you end up with an error, that your CloudFormation Stack cannot be updated, try to remove the custom > capacities configuration from your serverless.yml file and deploy the service without any Auto Scaling configuration. After that, just re-add your previous configuration and deploy your service again.
DynamoDB
The example serverless configuration above works fine for a DynamoDB table CloudFormation resource like this:
resources:
Resources:
CustomTable:
Type: AWS::DynamoDB::Table
Properties:
TableName: custom-table
AttributeDefinitions:
- AttributeName: key
AttributeType: S
KeySchema:
- AttributeName: key
KeyType: HASH
ProvisionedThroughput:
ReadCapacityUnits: 5
WriteCapacityUnits: 5
GlobalSecondaryIndexes:
- IndexName: custom-index-name
KeySchema:
- AttributeName: key
KeyType: HASH
Projection:
ProjectionType: ALL
ProvisionedThroughput:
ReadCapacityUnits: 5
WriteCapacityUnits: 5
License
Feel free to use the code, it's released using the MIT license.
Thanks
- TrentBartlem's Gist
- daniel's post in the AWS Developer Forums
Contribution
You are welcome to contribute to this project! ?
To make sure you have a pleasant experience, please read the code of conduct. It outlines core values and beliefs and will make working together a happier experience.
Local Development
If you plan to change the TypeScript files and link the package to another project, use the link and build yarn commands:
$ > yarn link
$ > yarn build:watch # or "yarn build"
Use your local build of the package in another project:
$ > yarn link serverless-dynamodb-autoscaling