Do not understand the text in health check

Question

I am looking at the following page where it says:

Sum over backend services. If a backend is used by multiple backend services, the backend instances are contacted as frequently as the sum of frequencies for each backend service's health check.

Now I don't quite understand what the following means:

...the backend instances are contacted as frequently as the sum of frequencies for each backend service's health check.

Can someone please help me break this down.

Thank you!

Answer 1

... the sum of frequencies for each backend service's health check. refers to the sum of the Check interval check-interval configuration flag for each service defined. The default for each is 5s

---

What is a backend service?

A backend service defines how Cloud Load Balancing distributes traffic. The backend service configuration contains a set of values, such as the protocol used to connect to backends, various distribution and session settings, health checks, and timeout

---

What is check-interval config flag?

From Docs

The check interval is the amount of time from the start of one probe issued by one prober to the start of the next probe issued by the same prober. Units are seconds.