Check label strictly by adding more store info

[overvenus]

User may have misconfigured labels, such as two different labels on one machine. This may misguide PD to schedule the majority peers on the machine. When it is down, TiDB cluster may not make progress.

To prevent this error, we can add additional info in the PutStoreRequest, such as hostname or IP. PD can check label strictly using this info.

Cc @nolouch

[disksing]

I personally don't like the idea. It is better not to expect the software to do the right thing in the wrong configuration because it inevitably leads to doing the wrong thing in the right configuration. For example, what if 2 hosts have the same hostname? What if 2 tikv-servers from different hosts share the same address (entirely possible, such as using DNS or NAT)?

[siddontang]

here the main problem is that if the user misconfigures the label, how can we do it? still providing the services or not?

[disksing]

I believe that the service should be provided according to the user's configuration, based on the fact that we can't accurately determine whether the configuration is correct.