Industrial fault description:

F7 is a fault which occurs in a third-party service and then leads to a failure.
We always need to call a microservice that maintained by a third-party or company.
Sometimes the response from the microservice maintained by others may be timeout and returns nothing, or even return wrong information.
Then this kind of fault occurs.



TainTicket replicated fault description:

In TainTicket system, if the user want to buy a ticket but the balance is not enough, the system will call a third-party service implemented by Node.js to get the ticket money. 
Sometimes there will be a delay caused by insufficient resource such as CPU in this third-party service, then the timeout will be triggered and the fault occurs.