Atomic access to multiple attributes for ensuring consistency

[struberg]

Initiated by @tomas-langer we had a lot of discussions during the last EG meetings about consistent atomic access to configuration.

Consider having myapp.host + myapp.port which belong together.

now if you switch from myserver:8080 to otherserver:9090, then there is no guarantee to have consistent access.

String url = config.getValue("myapp.host");
Integer port = config.getValue("myapp.port);

Imagine that inbetween those calls the config gets updated :(

This might require to switch back ConfigSource from getPropertyNames() to go Map<String, String> getProperties() as we had it in DeltaSpike and my initial proposal.
Or find another solution.

[struberg]

This is now resolved via the new ConfigSnapshot mechanism.