Optimize CDN performance and resolve latency issues for MediaTailor - AWS Elemental MediaTailor
Performance measurement techniquesCDN cache performance issuesCommon HTTP error resolution

Optimize CDN performance and resolve latency issues for MediaTailor

AWS Elemental MediaTailor content delivery network (CDN) integration performance directly impacts viewer experience and ad delivery quality. If you experience slow response times or performance degradation:

Performance measurement techniques

Before troubleshooting performance issues, establish baseline measurements and ongoing monitoring:

  1. Measure key performance metrics:

    • Response times: Manifest requests should complete within 200ms, segment requests within 100ms

    • Cache hit ratios: Content segments >95%, ad segments >90%

    • Origin request volume: Should be less than 5% of total requests when cache is optimized

    • Time to first frame: Initial playback should start within 2-3 seconds

  2. Use performance measurement tools:

    • CDN analytics dashboards: Monitor cache performance, response times, and error rates

    • CloudWatch metrics: Track MediaTailor service metrics including GetManifest.Latency

    • Browser developer tools: Measure client-side performance and network timing

    • Command-line tools: Use curl with timing options to measure specific requests

  3. Implement continuous monitoring:

    • Set up automated performance alerts for response time degradation

    • Monitor performance across different geographic regions

    • Track performance during peak traffic periods

    • Compare performance metrics before and after configuration changes

Performance measurement resources:

CDN cache performance issues

Cache performance problems are among the most common CDN integration issues. These problems affect all MediaTailor implementations and can significantly impact viewer experience and costs.

Low cache hit ratio

Symptoms: High origin request volume, increased latency, higher bandwidth costs, poor viewer experience

Target values:

  • Content segments: 95% or higher cache hit ratio

  • Ad segments: 90% or higher cache hit ratio

  • Manifests: Varies by implementation (personalized manifests should not be cached)

Common causes:

  • Incorrect TTL settings for different content types

  • Cache key configuration includes unnecessary query parameters

  • Cache-control headers from origin not properly configured

  • Frequent cache invalidations or purges

  • Geographic distribution issues (content not cached at edge locations)

Solutions:

  1. Review and optimize TTL settings:

    • Content segments: Set TTL to match segment duration or longer

    • Ad segments: Set TTL to 24 hours or longer for reusable ads

    • Static assets: Set TTL to 24 hours or longer

    For comprehensive TTL recommendations and caching optimization strategies, see Caching optimization for CDN and MediaTailor integrations.

  2. Optimize cache key configuration:

    • Remove unnecessary query parameters from cache keys

    • Ensure only content-affecting parameters are included

    • Normalize parameter order and case sensitivity

  3. Verify origin cache-control headers are properly set

  4. Implement origin shield (or equivalent CDN functionality) for high-traffic implementations. Origin shield functionality is available across major CDNs but might have different names (such as CloudFront Origin Shield, Fastly Shield, Cloudflare Argo Tiered Cache). If your CDN doesn't offer this functionality, it can be enabled in MediaTailor when you contact AWS Support.

  5. Review cache invalidation strategies and reduce unnecessary purges

Validation steps:

  1. Monitor cache hit ratios using CDN analytics dashboards

  2. Test specific URLs with curl to verify cache headers

  3. Compare origin request volume before and after changes

High origin request volume

Symptoms: Unexpectedly high number of requests reaching MediaTailor origin, increased origin server load, higher costs

Expected pattern: Origin requests should be less than 5% of total viewer requests when cache hit ratios are optimal

Common causes:

  • Cache misses due to low TTL values

  • Cache key fragmentation (too many unique cache keys)

  • Geographic traffic spikes in regions without cached content

  • Frequent cache invalidations

Solutions:

  1. Analyze request patterns to identify cache miss causes

  2. Optimize TTL settings based on content type and update frequency

  3. Implement cache warming strategies for new content

  4. Consider origin shield implementation (available across major CDNs with different names - see Origin Shield implementation for details)

Alert threshold: Set alerts when origin requests exceed 10% of total requests or increase by 50% over baseline

Common HTTP error resolution

HTTP errors in CDN integrations often indicate configuration issues or service problems. These error patterns are consistent across all MediaTailor implementations.

404 Not Found errors

Symptoms: Manifest or segment requests return HTTP 404, players fail to load content, "MANIFEST_LOAD_ERROR" in player logs

Common causes:

  • Incorrect CDN origin configuration (wrong MediaTailor endpoint URL)

  • Missing or incorrect cache behavior path patterns

  • URL rewriting issues in CDN configuration

  • MediaTailor configuration name or playback endpoint errors

  • Timing issues with live content (requesting future segments)

Diagnostic steps:

  1. Test the same URL directly against MediaTailor origin (bypass CDN)

  2. Verify CDN origin configuration matches MediaTailor playback endpoint

  3. Check CDN cache behavior path patterns and precedence

  4. Review CDN access logs for request routing details

  5. Validate MediaTailor configuration name and region settings

Solutions:

  • Correct CDN origin configuration to match MediaTailor playback endpoint

  • Update cache behavior path patterns to properly route requests

  • Fix URL rewriting rules if applicable

  • Verify MediaTailor configuration exists and is active

403 Forbidden errors

Symptoms: Requests return HTTP 403, access denied messages, authentication failures

Common causes:

  • Missing or incorrect query parameters required by MediaTailor

  • CDN not forwarding required headers or parameters

  • IP address restrictions or geographic blocking

  • Authentication token issues (if using signed URLs)

Solutions:

  • Verify all required query parameters are included and forwarded

  • Check CDN configuration for header and parameter forwarding

  • Review IP restrictions and geographic settings

  • Validate authentication tokens and signing processes

400 Bad Request errors

Symptoms: Requests return HTTP 400, malformed request errors, parameter validation failures

Common causes:

  • Malformed query parameters or URL encoding issues

  • Invalid parameter values or formats

  • Missing required parameters for specific MediaTailor features

  • URL length limitations exceeded

Solutions:

  • Validate query parameter formats and URL encoding

  • Check parameter values against MediaTailor API requirements

  • Ensure all required parameters are included

  • Review URL length and consider parameter optimization

5xx Server errors

Symptoms: Requests return HTTP 500, 502, 503, or 504 errors, intermittent service failures

Common causes:

  • MediaTailor service issues or capacity limitations

  • CDN origin connectivity problems

  • Timeout issues due to slow origin responses

  • Temporary service degradation

Solutions:

  • Check AWS Service Health Dashboard for MediaTailor service status

  • Verify CDN origin connectivity and timeout settings

  • Implement retry logic with exponential backoff

  • Monitor MediaTailor CloudWatch metrics for service health

  • Contact AWS Support if issues persist

  1. Measure baseline performance:

    • Test manifest request response times directly to MediaTailor (target: <200ms)

    • Measure CDN response times for manifest requests (target: <100ms for cache hits)

    • Check segment loading times from both origin and CDN

  2. Analyze CDN performance:

    • Check cache hit ratios for content segments (target: >80% for popular content)

    • Verify origin shield (or equivalent CDN functionality) is enabled and configured in the same AWS Region as your origin. Different CDNs use different names for this functionality

    • Monitor CDN edge location performance and geographic distribution

Performance benchmarks:

  • Monitor manifest generation response times and compare against your baseline performance

  • CDN cache hits are significantly faster than origin requests

  • ADS response times should not cause manifest generation delays

Additional troubleshooting resources:

Success criteria: When resolved, response times should meet target benchmarks (manifests less than 200ms, segments less than 100ms), cache hit ratios should exceed 90% for most content types, and origin request volume should be less than 5% of total requests. Performance should be consistent across all geographic regions and device types.