In addition, the network isn't just up or down. It's varying shades (dare I say, 50 shades?) of down or broken. A single machine might not be accessible due to a switch issue. An entire rack or aisle might be compromised by a bad router or faulty routing table. A network cable might be flaky. The truth is you just don't know, and that's all inside a single LAN.
Your service discovery system could be able to see service {A,B,C}, but service A can't talk to B or C due to network issues. It happens.
In addition, the network isn't just up or down. It's varying shades (dare I say, 50 shades?) of down or broken. A single machine might not be accessible due to a switch issue. An entire rack or aisle might be compromised by a bad router or faulty routing table. A network cable might be flaky. The truth is you just don't know, and that's all inside a single LAN.
Your service discovery system could be able to see service {A,B,C}, but service A can't talk to B or C due to network issues. It happens.
http://www.rgoarchitects.com/Files/fallacies.pdf