⚡️ serverless-provisioned-concurrency-autoscaling

Serverless Plugin for AWS Lambda Provisioned Concurrency Auto Scaling configuration.

Related blog post can be found on the Neiman Marcus Medium page.

Usage

Add the NPM package to your project:

$ npm install serverless-provisioned-concurrency-autoscaling

Add the plugin to your serverless.yml:

Use version 1.9.1 for Serverless 1/ Serverless 2.

Use version 2.0.1 for Serverless 3.

plugins:
  - serverless-provisioned-concurrency-autoscaling

Configuration

Add concurrencyAutoscaling parameters under each function you wish to autoscale in your serverless.yml.

Add customMetric: true if you want to use Maximum instead of Average statistic.

Minimal Configuration

functions:
  hello:
    handler: handler.hello
    provisionedConcurrency: 1
    concurrencyAutoscaling: true

Full Configuration

functions:
  world:
    handler: handler.world
    provisionedConcurrency: 1
    concurrencyAutoscaling:
      enabled: true
      alias: provisioned
      maximum: 10
      minimum: 1
      usage: 0.75
      scaleInCooldown: 0
      scaleOutCooldown: 0
      customMetric:
        statistic: maximum
      scheduledActions:
        - name: OpenOfficeTime
          startTime: "2025-01-01T00:00:00.000Z"
          endTime: "2025-01-01T23:59:59.999Z"
          timezone: "America/Chicago"
          schedule: "cron(30 8 ? * 1-6 *)"
          action:
            maximum: 100
            minimum: 10
        - name: CloseOfficeTime
          startTime: "2025-01-01T00:00:00.000Z"
          endTime: "2025-01-01T23:59:59.999Z"
          timezone: "America/Chicago"
          schedule: "cron(30 17 ? * 1-6 *)"
          action:
            maximum: 10
            minimum: 1
        - name: BlackFridayPeak1
          startTime: "2025-01-02T00:00:00.000Z"
          endTime: "2025-01-02T23:59:59.999Z"
          timezone: "America/New_York"
          schedule: "at(2025-01-02T12:34:56)"
          action:
            maximum: 50
            minimum: 5
        - name: BlackFridayPeak2
          startTime: "2025-01-03T00:00:00.000Z"
          endTime: "2025-01-03T23:59:59.999Z"
          timezone: "Europe/Warsaw"
          schedule: "rate(1 hour)"
          action:
            maximum: 50
            minimum: 5

That's it! With the next deployment, serverless will add Cloudformation resources to scale provisioned concurrency!

You must provide at least provisionedConcurrency and concurrencyAutoscaling to enable autoscaling. Set concurrencyAutoscaling to a boolean, or object with configuration. Any omitted configuration will use module defaults.

Defaults

alias: provisioned
maximum: 10
minimum: 1
usage: 0.75
scaleInCooldown: 0
scaleOutCooldown: 0

Change in Default Behavior: Starting in v1.7.0, the default scaleInCooldown is zero, not 120. This is backwards compatible, but different default behavior. This is in line with AWS' default scaleInCooldown.

Scheduled Actions

For more details on Scheduled Actions formats see the AWS CloudFormation ScheduledAction description.

Description of scheduledActions's properties:

Attribute	Description	Required	Example
endTime	The date and time that the action is scheduled to end, in UTC.	no	2025-12-31T23:59:59.999Z
startTime	The date and time that the action is scheduled to begin, in UTC.	no	2025-01-01T00:00:00.000Z
timezone	Timezone for startTime and endTime. Needs to be the canonical names of the IANA (supported by Yoda-Time).	no	America/Chicago
name	The name of the scheduled action unique among all other scheduled actions on the specified scalable target.	yes	OpenOfficeHourScheduleStart
schedule	One of three string formats: at, cron or rate (see next table).	yes	cron(* 30 8 * 1-6 *)
action	Object of minimum and maximum properties. At least one is required.	yes	minimum: 100 maximum: 105

Description of schedule's properties:

For more details on schedule syntax see:

• AWS CloudFormation ScheduledAction description
• AWS Schedule Expressions for Rules (cron)
• AWS Put Scheduled Action - Timezone

Attribute	Description	Format	Example
at	A start (a point in time)	at(yyyy-mm-ddThh:mm:ss)	at(2025-01-02T00:00:00)
cron	A cron syntax for recurring schedule	cron(fields)	cron(30 17 ? * 1-6 *)
rate	A rate	rate(value unit)	rate(16 minuets)

Known Issues/Limitations

N/A

Authors

• Clay Danford
• Dawid Boissé

Contributors

• Vinoth Kumar Chandrasekar

Conduct / Contributing / License

• Refer to our contribution guidelines to contribute to this project. See CONTRIBUTING.md.
• All contributions must follow our code of conduct. See CONDUCT.md.
• This project is licensed under the Apache 2.0 license. See LICENSE.

Acknowledgments

• serverless-dynamodb-autoscaling - Original plugin this module is based on.