When a new episode is released on your RSS feed, the Flex system rapidly detects and imports the episode, decreasing the time from publishing to delivery of audio files through the Acast system.
Acast re-encodes all source MP3 files to ensure a constant bitrate - this is a requirement of the dynamic audio engine, to ensure that dynamic content like ads are stitched in the exact right point of the file.
Rapid response times and auto-scaling ensure this process time is minimal. However, for the very small number of requests that may come with importing and encoding is occurring, the Flex system makes it possible to customise how to handle them.
In the event of unavailable re-encoded content, the Flex system can send:
HTTP 429 - a 'return and try-again-later' error message
This will tell the listening platform to try and retrieve the content again when the encoding process is complete and the file can be delivered. This option optimises to deliver an Acast dynamically stitched file to every request, maximising any potential ad delivery.
A redirect to source content until the import process is finished
This will redirect any requests coming in during the import process to deliver a version of the file from your own system. The request is still logged and added to the data pipeline, but the file will not be stitched using Acast's dynamic audio engine. This option optimises to deliver a file of any kind to every request, maximising the speed at which files are delivered to all requests.
These options only concern a small number of requests from the moment an episode is published, or in the event the Flex systems attempts to import an incompatible or broken file. For more information on what these options mean, please reach out to your technical account manager.