AWS Elemental MediaTailor ad insertion event flow

AWS Elemental MediaTailor processes manifest personalization for server-side ad insertion through a predictable sequence of events. Understanding this event flow helps you comprehend how MediaTailor transforms ad opportunities into personalized viewing experiences and provides a foundation for troubleshooting when issues occur.

Each ad insertion opportunity follows a chronological sequence of events that MediaTailor logs for visibility and monitoring. These events represent key milestones in the manifest personalization process, from detecting an ad opportunity to delivering tracking information.

Standard event sequence

When MediaTailor successfully processes an ad insertion opportunity, the following sequence of events typically occurs:

1. Ad opportunity detection - MediaTailor detects an ad marker (such as SCTE-35) in the content manifest, indicating an ad personalization opportunity is available.

2. Ad decision server request - MediaTailor sends a request to the configured ad decision server (ADS) to retrieve advertisements for the detected opportunity, including viewer parameters and ad break duration.

3. Ad response processing - MediaTailor receives a response from the ADS containing ad creative information, tracking URLs, and metadata about the advertisements to be included. For more information about VAST, VMAP, and VPAID response formats, see Ad server integration requirements.

4. Manifest personalization - MediaTailor successfully processes the ad response, transcodes the advertisements if necessary, and generates a personalized manifest that includes relative URLs for both the ad segments and origin content. MediaTailor then sends the personalized manifest to the playback device.

5. Tracking beacon activation - A tracking beacon is fired to report ad events (such as impressions, quartiles, and completion) back to the ad server or other measurement systems. In server-side reporting mode (default), MediaTailor fires the beacon based on player segment requests. In client-side reporting mode, the playback device fires the beacon using URLs provided in the personalized manifest.

Typical timing: This entire sequence usually completes within 2-5 seconds, depending on ad decision server response time and ad creative processing requirements.

Common event variations

Not all ad insertion attempts follow the standard successful sequence. MediaTailor handles various scenarios that can alter the event flow:

Empty ad response scenario

When the ad decision server returns no advertisements:

1. Ad opportunity detection occurs normally

2. Ad decision server request is sent successfully

3. ADS returns an empty response with zero ads

4. No ads are included in the personalized manifest for this opportunity

This is a normal scenario that can occur due to ad inventory availability, targeting criteria, or business rules configured in the ad decision server. In this case, the underlying content will be displayed unless the stream is a live or live-to-VOD stream and slate has been configured. For more information, see MediaTailor slate ad insertion.

Error scenarios

When technical issues prevent successful ad insertion, the event flow might be interrupted at various points:

• Ad decision server timeout - The request to the ADS exceeds the configured timeout threshold, preventing ad retrieval.

• Communication errors - Network or connectivity issues prevent MediaTailor from reaching the ad decision server.

• Response parsing errors - The ADS returns a response that MediaTailor cannot parse due to invalid VAST format or structure.

In error scenarios, MediaTailor typically continues with content playback without ads, ensuring uninterrupted viewer experience. For live or live-to-VOD streams with slate configured, slate content might be displayed instead. For more information, see MediaTailor slate ad insertion.

VAST redirect scenarios

When the initial VAST response contains a redirect to another ad server:

1. Ad opportunity detection and initial ADS request occur normally

2. Initial response contains a redirect instruction

3. MediaTailor follows the redirect to retrieve the final ad response

4. Manifest personalization proceeds with the final ad content

5. Tracking beacon activation occurs normally

VAST redirects are common in programmatic advertising and allow for ad server chaining and real-time decisioning. MediaTailor allows up to 7 wrapper redirects and unlimited HTTP redirects during the ad retrieval process.

Event timing overview

Understanding the timing characteristics of MediaTailor event flows helps set appropriate expectations for ad insertion performance:

• Ad opportunity detection - Occurs when MediaTailor receives a GetManifest request from the player and encounters the ad markers in the content manifest.

• Ad decision server interaction - Typically takes 100-500 milliseconds, depending on ADS response time and network conditions.

• Manifest personalization - Usually completes within 50-200 milliseconds after receiving the ADS response.

• Tracking beacon timing - Varies by reporting mode. For server-side beacons, timing is based on segment requests from the client player; client-side beacons fire based on player implementation.

Performance considerations: The total time from ad opportunity detection to manifest delivery should typically remain under 5 seconds to maintain optimal viewer experience. Individual components complete in milliseconds as described above. However, the 5-second threshold accounts for potential timeout values, retry attempts, and network variability that can occur during the complete ad insertion workflow. Longer delays might indicate ADS performance issues or network connectivity problems.

Using event flow knowledge

Understanding MediaTailor event flow provides the foundation for:

• Implementation planning - Knowing the event sequence helps in designing player integration and ad server configuration.

• Performance optimization - Understanding timing expectations enables identification of bottlenecks and optimization opportunities.

• Troubleshooting preparation - Familiarity with normal event flows makes it easier to identify when something goes wrong.

For detailed troubleshooting guidance using event flow analysis, see Troubleshooting. For technical details about event logging and monitoring, see Viewing logs.