MediaTailor session variable ad skipping troubleshooting

Session variables play a critical role in ad targeting and selection in AWS Elemental MediaTailor. Incorrect session variable configuration is a common cause of ad skipping issues. This comprehensive troubleshooting guide explains how to identify and resolve session variable problems that can prevent successful ad insertion.

Common session variable issues

Common session variable issues include the following:

• Missing required variables: Your ad decision server might require specific variables that aren't being provided.

• Incorrect variable syntax: Variables must use the correct syntax (for example, [session.id] instead of ${session.id}).

• URL encoding issues: Special characters in variable values might need proper URL encoding.

• Inconsistent player parameters: Player parameters must be consistently passed across sessions.

• Dynamic variable resolution failures: Variables that can't be resolved are replaced with empty strings.

• SCTE-35 UPID parsing issues: Problems with segmentation UPID processing can cause session variable resolution failures.

Verifying session variable resolution

To verify that your session variables are being properly resolved:

1. Enable debug logging for your MediaTailor configuration

2. Check the MediaTailor/AdDecisionServerInteractions log group for the actual ADS request URLs

3. Verify that all variables in the template URL have been replaced with appropriate values

4. Look for any variables that were replaced with empty strings, which may indicate resolution failures

SCTE-35 UPID parsing troubleshooting

Problems with SCTE-35 segmentation UPID processing can cause session variable issues:

• Format requirements: UPID must have segmentation_upid_type of 12 and include format_identifier for proper processing

• Parsing rules: Decoded UPID can contain colon delimiters for multiple values. The number of template variables and decoded UPID tokens must be equal

• Invalid formats: Avoid double colons with no values (e.g., :: or :46175218::4053) as these cause parsing failures