I am building a pub/sub system via event bus in my SFDC instance and one of my subscribers takes more than 24 hours to process requests (it's a human transition system). Is it possible to extend the message durability to more than 24 hours?
Event Retention in Event Bus as per documentation currently is:
High-volume platform event messages are stored for 72 hours (3 days). Standard-volume platform event messages are stored for 24 hours (1 day). You can retrieve past event messages when using CometD clients to subscribe to a channel.
so the best chance to wait for the longest interval is to publish High-Volume platform events (since sprint'19).
For efficient processing of high loads of incoming event messages, high-volume platform events are published asynchronously
Also, please note that the allocations are based on the salesforce edition.