Analyze Application Load Balancer Logs with Amazon CloudWatch Logs

This article explains how to analyze Application Load Balancer logs using Amazon CloudWatch Logs, which now supports ALB logs as vended logs with structured JSON formatting.

• All three ALB log types (access, connection, health check) delivered as structured JSON with named fields
• Enable ALB log ingestion via CloudWatch telemetry enablement rules for automatic configuration across organization
• Deploy sample CloudWatch dashboard using provided CloudFormation template for unified visualization
• Use Log Analytics queries to attribute 5xx errors to load balancer vs. application, identify slow routes, and analyze per-target reliability
• Create Log Alarms directly from queries to alert on health check failures without custom metrics
• Optionally enrich logs at ingestion using CloudWatch Logs pipelines with GeoIP and type conversion processors
• Centralize logs from multiple accounts and regions into single destination account

ALB logs now integrate seamlessly with CloudWatch Logs, eliminating infrastructure overhead and providing comprehensive observability for load balancer operations.