Currently, the reverse-read ordering option in the Atom Feed service does not work as intended. With that ordering, the high water mark will actually be set to the last event in the feed rather than the first. The end result is that new events are never sent to consumers of the service until the high water mark even falls off the feed (i.e., is archived). Additionally, the Atom Feed service will read the entire available feed every time it checks for new events, which is expensive and wasteful.
One fix would be to change when ordering is applied, and to set the high water mark appropriately. That is, set the high water mark to the head event of the non-reversed stream, and do not reverse the stream until after determining which events are new events.
- Reverse order feed service reading works
- That is, the issues where events are re-read multiple times and new events are ignored are fixed.