Function mysql_snapshot_failpoint_pause 

async fn mysql_snapshot_failpoint_pause(table: &str)

Test-only pause point, run before this worker reads any rows of table. Configuring the failpoint as mysql_snapshot_pause=return(<table name>) holds the snapshot of that table until the failpoint is deactivated. return(<table name>:<millis>) holds it for that many milliseconds instead. The snapshot then completes in the same dataflow incarnation.