Industrial fault description:

The grid-loading process takes too much time.
Too many nested "select" and "from" clauses are in the constructed SQL statement.


TrainTicket replicated fault description:

To simulate the nested select clauses, one procedure of mysql to sleep 10s was created in ts-voucher-service.
Since the front stage has a 5s limit of network request, the query of one order's voucher will be out of time.