Both run_check_repl_dbhash.js and run_check_repl_dbhash_background use the phrase "data consistency checks failed" in their assertion messages. However, these two assertion failing mean different things: run_check_repl_dbhash.js failing represents permanent data loss and run_check_repl_dbhash_background.js failing typically represents transient incorrect query results (specifically around reading at a timestamp).
There is a desire to have an automated system distinguish these two cases from the assertion messages alone. This ticket is to update one or both of these files so the hooks fail with different assertion messages than each other. (One should probably also not be a substring of the other either.) This ticket must be backported all the way to the 4.0 branch—when run_check_repl_dbhash_background.js was first introduced—for the automated system to get the full benefit.