> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Monitoring Options

> This article explores monitoring AWS Lambda using CloudWatch, Lambda Insights, AWS X-Ray, and VPC Flow Logs for troubleshooting and optimizing serverless applications.

In this lesson, we explore how to monitor AWS Lambda using Amazon CloudWatch, Lambda Insights, AWS X-Ray, and VPC Flow Logs. These tools provide metrics, logs, and tracing to help troubleshoot and optimize serverless applications at scale.

## Amazon CloudWatch Metrics

AWS Lambda automatically sends key performance metrics to [Amazon CloudWatch](https://aws.amazon.com/cloudwatch/), allowing you to track function execution, errors, and performance trends.

| Metric               | Description                                    | Default |
| -------------------- | ---------------------------------------------- | ------- |
| Invocations          | Total number of function calls                 | ✔️      |
| Duration             | Time taken per invocation (in milliseconds)    | ✔️      |
| Errors               | Number of failed invocations                   | ✔️      |
| Throttles            | Invocations throttled due to concurrency limit | ☐       |
| IteratorAge          | Lag time for stream-based event sources        | ☐       |
| DeadLetterErrors     | Failures delivering to a dead-letter queue     | ☐       |
| ConcurrentExecutions | Real-time concurrency usage                    | ☐       |

<Callout icon="lightbulb" color="#1CB2FE">
  To collect additional metrics, enable enhanced monitoring in your function’s configuration or use [AWS CLI](https://aws.amazon.com/cli/) / [AWS SDKs](https://aws.amazon.com/developer/tools/) to customize metric filters.
</Callout>

If you need an aggregated view across all functions, CloudWatch dashboards can display combined metrics and alert on threshold breaches:

<Frame>
  ![The image is an informational slide about Amazon CloudWatch, detailing its automatic monitoring capabilities and additional metrics available, such as request numbers, duration, and concurrency limits.](https://kodekloud.com/kk-media/image/upload/v1752863156/notes-assets/images/AWS-Lambda-Monitoring-Options/amazon-cloudwatch-monitoring-metrics-slide.jpg)
</Frame>

## Lambda Insights

[Lambda Insights](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Lambda-Insights.html) extends CloudWatch with deeper visibility into function behavior, resource utilization, and performance anomalies.

Key benefits:

* Comprehensive dashboard for all functions in an AWS account or region
* Detailed per-function views of CPU, memory, disk, and network usage
* Customizable alerts on unusual trends or resource spikes

<Frame>
  ![The image shows a dashboard from AWS Lambda Insights, displaying performance monitoring metrics such as invocations, errors, duration, throttles, memory usage, CPU usage, and network usage.](https://kodekloud.com/kk-media/image/upload/v1752863158/notes-assets/images/AWS-Lambda-Monitoring-Options/aws-lambda-insights-performance-dashboard.jpg)
</Frame>

Use Lambda Insights to:

* Troubleshoot individual functions efficiently
* Analyze resource utilization over time
* Detect performance bottlenecks and anomalies

## AWS X-Ray Tracing

[AWS X-Ray](https://aws.amazon.com/xray/) provides distributed tracing for end-to-end request analysis. By instrumenting your Lambda functions with X-Ray, you can:

* Visualize service maps and trace requests through microservices
* Measure latency and identify performance hotspots
* Pinpoint errors across the execution flow

<Callout icon="triangle-alert" color="#FF6B6B">
  Enabling AWS X-Ray may incur additional costs and slight latency overhead. Evaluate tracing requirements before enabling in production.
</Callout>

<Frame>
  ![The image is a slide about AWS X-ray, a monitoring and troubleshooting tool, highlighting features like visual mapping and identifying performance bottlenecks and errors.](https://kodekloud.com/kk-media/image/upload/v1752863160/notes-assets/images/AWS-Lambda-Monitoring-Options/aws-xray-monitoring-troubleshooting-slide.jpg)
</Frame>

## VPC Flow Logs for Network Monitoring

To capture TCP/IP-level details such as source and destination IP addresses, use [VPC Flow Logs](https://docs.aws.amazon.com/vpc/latest/userguide/flow-logs.html). Since Lambda functions run outside your VPC by default, you must configure them to run within a VPC to generate flow logs.

Steps to enable:

1. Attach your Lambda function to a VPC subnet and security group.
2. Create a VPC Flow Log to an Amazon CloudWatch Logs group or Amazon S3 bucket.
3. Analyze logs for network performance and security insights.

<Callout icon="lightbulb" color="#1CB2FE">
  Ensure your Lambda execution role has permissions for both VPC configuration and flow log creation (`ec2:CreateFlowLogs`, `logs:CreateLogGroup`, `logs:PutLogEvents`).
</Callout>

## References

* [AWS Lambda Documentation](https://docs.aws.amazon.com/lambda/latest/dg/welcome.html)
* [Amazon CloudWatch Metrics](https://docs.aws.amazon.com/lambda/latest/dg/monitoring-metrics.html)
* [Lambda Insights Overview](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Lambda-Insights.html)
* [AWS X-Ray Developer Guide](https://docs.aws.amazon.com/xray/latest/devguide/aws-xray.html)
* [VPC Flow Logs User Guide](https://docs.aws.amazon.com/vpc/latest/userguide/flow-logs.html)

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