Sequence synchronization and possibility of conflicts in an online upgrade

[jkburges]

Consider the following scenario:

Provider sequence is 1 After sequence sync, subscriber sequence is 1000 (due to buffer) Record inserted to subscriber, gets ID 1000 1000 records inserted to provider

Is it possible (or likely) that the provider will end up with a record having ID 1000 (and therefore cause a conflict)?

The context in which I'm wondering this is regarding cutting over an application from provider to subscriber (for an online upgrade), and I'm not sure whether the cutover has to be instantaneous so that either only provider or subscriber is getting writes, or whether it's tolerable different app instances to be writing to both of provider and subscriber for some period.