AWS Lambda Invocations

AWS Lambda considers any time a lambda function is invoked in its invocation metric. This does not include throttled attempts to run the function. Because this is a metric that determines billing, it’s important to monitor any major changes. Blue Matador provides anomaly detection on this metric so you can know about potentially expensive fluctuations in invocations.

Causes

• If you are experiencing higher than expected invocations, the following may be occurring:
• Code that writes to the event source for your function may be malfunctioning and writing more to DynamoDB, Kinesis, S3, SQS, etc.
• Your lambda function might be failing with errors that are causing retries and boosting your invocation count
  
  
• If you are experiencing lower than expected invocations, the following may be occurring:
• Code that writes to your event source may be malfunctioning and not writing data
• Permission issues may prevent your code from accessing the event source
• Invocations may be throttled. This is especially true if your function is running against your unreserved concurrency limit. It’s possible that another function is exhausting your unreserved concurrency

Resources

• Invocation Sources (AWS Documentation)
• Cloudwatch Metrics for Lambda (AWS Documentation)