DNS resolver can run for longer than the given timeout

It's very hard to reproduce, we found the problem because we have a 60s timeout for our web server that we kept busting, even with email-validator's default 15s timeout.

Disabling check_availability solved our problem.

The problem

The problem lies within:

response = dns_resolver.resolve(domain, "MX")

( https://github.com/JoshData/python-email-validator/blob/main/email_validator/deliverability.py#L40 )

While debugging, what I can see is that the resolver goes through a loop, and only checks the timeout between calls. It also does some time.sleep()
That means that if a call or a sleep is longer than the timeout, it doesn't get interrupted and can thus run for longer

The solution

Using signal, we could interrupt the process. See https://stackoverflow.com/a/494273

This package does it: https://github.com/pnpnpn/timeout-decorator

I'll try implementing the stackoverflow suggestion on my end and write back with news

Bắt đầu trong deliverability.py tại lệnh gọi dns_resolver.resolve(domain, "MX") và theo dõi cách timeout được cấu hình được truyền qua khi check_availability được bật. Tái hiện hoặc điều tra vòng lặp resolver và hành vi sleep được mô tả trong issue. Được xem là hoàn tất khi việc phân giải DNS không chạy quá thời gian timeout đã cho và hành vi deliverability hiện có được giữ nguyên.