serverless-timeout-alarms

Add CloudWatch metric filter and alarm for Lambda timeouts automatically during Serverless packaging.

• Creates a CloudWatch Logs metric filter that counts occurrences of timeout logs per function
• Adds a CloudWatch Alarm on that metric with configurable threshold/evaluation periods
• Supports global defaults and per-function overrides

Installation

npm install -D serverless-timeout-alarms

Usage

Add the plugin and configure global defaults in your serverless.yml:

plugins:
  - serverless-timeout-alarms

custom:
  timeoutAlarm:
    enabled: true
    namespace: Serverless/LambdaTimeouts
    filterPattern: timeout
    threshold: 1
    period: 300
    evaluationPeriods: 1
    statistic: Sum
    treatMissingData: notBreaching
    # Optional: SNS topic ARN for alarm actions
    # alarmActionSnsTopic: arn:aws:sns:us-east-1:123456789012:alerts

functions:
  hello:
    handler: src/handler.hello
    # Optional per-function override
    timeoutAlarm:
      enabled: true
      threshold: 2

When you run serverless package (or deploy), the plugin will add the following resources for each enabled function:

• AWS::Logs::MetricFilter to count timeout log events
• AWS::CloudWatch::Alarm on that metric

Alarm names use the format: [<stage>][<service>][<functionName>][TimeoutAlarm].

Configuration

Global custom.timeoutAlarm and per-function functions.<name>.timeoutAlarm support:

• enabled (boolean, default: true)
• namespace (string, default: Serverless/LambdaTimeouts)
• filterPattern (string, default: timeout)
• threshold (number, default: 1)
• period (seconds, default: 300)
• evaluationPeriods (number, default: 1)
• statistic (Sum | Average | Maximum | Minimum | SampleCount; default: Sum)
• treatMissingData (notBreaching | breaching | ignore | missing; default: notBreaching)
• alarmActionSnsTopic (optional string: SNS topic ARN)

If alarmActionSnsTopic is omitted, the alarm is created without actions; you can attach actions later.

Example metric name

For a service my-api, function getItem, stage prod:

/lambda/my-api/getItem/prod/timeoutCount

Quick deploy

Build and deploy/package as usual with Serverless:

npx serverless deploy
# or
npx serverless package

License

MIT