# CDN log interpretation and analysis techniques for MediaTailor
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AWS Elemental MediaTailor content delivery network (CDN) integration generates detailed logs that help you understand request patterns and identify issues. When analyzing content delivery network logs, focus on these key indicators:

**Note:** The following examples use Amazon CloudFront terminology. Other CDN providers may use different terms for similar concepts.

HTTP status codes  
+ `200` - Successful request
+ `404` - Resource not found (check routing rules and MediaTailor configuration)
+ `403` - Access denied (check CDN security settings and origin permissions)
+ `502/503/504` - Origin server errors (check MediaTailor service health and origin connectivity)

Cache behavior indicators  
+ `Hit` - Content served from CDN cache
+ `Miss` - Content fetched from origin
+ `RefreshHit` - Cached content validated with origin
+ `Error` - Request resulted in an error

Request patterns to monitor  
+ Manifest requests should typically result in `Miss` or `RefreshHit` due to low TTL settings
+ Content segments should show `Hit` for popular content
+ Ad segments may show `Miss` due to personalization

**Service health monitoring**

When analyzing CDN logs and troubleshooting issues, check MediaTailor service health to determine if problems are service-related:

AWS Service Health Dashboard  
Check current MediaTailor service status and any ongoing service events  
Access: [AWS Service Health Dashboard](https://status.aws.amazon.com/)  
Use this when: You see widespread 5xx errors or service timeouts in CDN logs

AWS Personal Health Dashboard  
View account-specific service health notifications and maintenance events  
Access: [AWS Personal Health Dashboard](https://console.aws.amazon.com/phd/home)  
Use this when: You need account-specific service health information or maintenance notifications

Amazon CloudWatch metrics monitoring  
Monitor MediaTailor service health indicators through CloudWatch metrics:  
+ `GetManifest.Errors` - Track manifest generation errors
+ `GetManifest.Latency` - Monitor response time performance
+ `AdDecisionServer.Errors` - Monitor ad server connectivity issues
+ `Origin.Errors` - Track origin server connectivity problems
Access: [CloudWatch Console](https://console.aws.amazon.com/cloudwatch/home)  
Use this when: You need detailed service performance metrics and historical trends

**Service health troubleshooting workflow:**

1. Check AWS Service Health Dashboard for current service status

1. Review AWS Personal Health Dashboard for account-specific notifications

1. Monitor CloudWatch metrics for service performance indicators

1. Correlate service health status with CDN log patterns and error rates

1. If service health is normal, focus on CDN configuration and origin server issues

**CDN log analysis resources**
+ [CloudFront access logs](https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/AccessLogs.html) - Complete guide to CDN log format and fields
+ [CloudFront real-time logs](https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/real-time-logs.html) - Real-time log streaming and analysis
+ [Analyzing log data with CloudWatch Logs Insights](https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/AnalyzingLogData.html) - Advanced log querying and analysis
+ [Monitor workload resources](https://docs.aws.amazon.com/wellarchitected/latest/reliability-pillar/monitor-workload-resources.html) - Well-Architected monitoring patterns