AWS mediatailor documentation change
Summary
Added documentation for manifest-based prefetch feature for live SGAI, including how to enable it and important CDN caching considerations.
Security assessment
The change documents a performance optimization feature (prefetch heartbeating) to reduce ad fill latency. It includes a configuration warning about CDN caching that could break the feature, but this is a functional consideration, not a security vulnerability. No security issues, vulnerabilities, or security features are mentioned.
Diff
diff --git a/mediatailor/latest/ug/sgai-live-configuration.md b/mediatailor/latest/ug/sgai-live-configuration.md index 36b3a683b..3621a3f6c 100644 --- a//mediatailor/latest/ug/sgai-live-configuration.md +++ b//mediatailor/latest/ug/sgai-live-configuration.md @@ -5 +5 @@ -Requirements for live SGAILive playback configurationSGAI live manifest requestsTesting SGAI live configuration +Requirements for live SGAILive playback configurationSGAI live manifest requestsManifest-based prefetch for live SGAITesting SGAI live configuration @@ -75,0 +76,15 @@ SGAI live manifests use the same URL pattern as traditional ad insertion: +## Manifest-based prefetch for live SGAI + +For live SGAI workflows, you can enable manifest-based prefetch heartbeating to reduce ad fill latency. Add `aws.guidedPrefetchMode=MANIFEST` to the manifest request: + + + https://your-config.mediatailor.region.amazonaws.com/v1/master/config-name/manifest.m3u8?aws.insertionMode=GUIDED&aws.guidedPrefetchMode=MANIFEST + +When enabled, MediaTailor appends a session identifier (`?aws.sessionId=<id>`) as a query parameter to each interstitial media manifest (`/v1/i-media`) URL in the multivariant playlist. Each time the player refreshes an i-media manifest, the request reaches MediaTailor with the session ID, which MediaTailor uses to identify the session and enqueue prefetch requests for upcoming ad breaks. + +###### Important + +**Do not cache i-media manifests in your CDN when using guided prefetch.** The prefetch heartbeating mechanism depends on the player's manifest refresh requests reaching MediaTailor directly. If your CDN caches and serves `/v1/i-media` responses, MediaTailor does not receive the heartbeat requests and cannot trigger prefetching. Configure your CDN to pass through `/v1/i-media/*` requests to MediaTailor when `aws.guidedPrefetchMode=MANIFEST` is in use. + +Guided prefetch is independent of the reporting mode. Whether you use server-side (default) or client-side (`aws.reportingMode=CLIENT`) tracking, beacons fire at playback time, not when ads are prefetched. For general information about how ad prefetching works in MediaTailor, see [Prefetching ads](./prefetching-ads.html). +