AWS Exam Guide: Using CloudWatch and CloudTrail for Lambda Root Cause Analysis

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The AWS Developer Associate exam's Domain 4 covers troubleshooting and optimization, specifically using CloudWatch Logs, Logs Insights, and CloudTrail to debug production issues. CloudWatch organizes log data into log groups, streams, and events, with Lambda automatically creating a log group per function and defaulting retention to never expire. Logs Insights provides a query language with commands such as filter, stats, parse, and sort to search and analyze log data for patterns like errors, slow invocations, and cold starts. Lambda's REPORT log lines include system-generated fields like @duration, @billedDuration, and @initDuration, which are essential for performance monitoring and cost tracking. Candidates are also expected to understand Embedded Metric Format for custom metrics and recognize common failure patterns across AWS service integrations.

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