If a write request succeeds on a set of systems in a managed routing session but the systems return a different number of affected rows, Unity makes tables involved in the request unrecoverable on the second system to respond. Unity assumes the first successful response is correct, and relays that request to the client. After the client receives that response, the rest of the systems must agree with it.
After a table becomes unrecoverable, re-synchronize and validate the table to return to the active state. Several Unity features can be used to do this.