a) Shared data source; each service writes pid/state to a file in the shared data store. It could be a single directory in a single server setup or a dedicated NFS/SMB server for hundreds/thousands of nodes.
b) Pub/Sub service; Kafka, et al, in which services simply subscribe to and publish to a central channel to see everyone else.
c) Determinism; You use predictable naming/addressing and simply infer. This is tricky to scale but not impossible.
d) Any number of stand alone discovery services ala Zookeeper or Eureka. They all end up being effectively the same pub/sub model as B, just prepackaged.
e) You don't discover shit, you have a single load balanced endpoints that can scale out instances as needed behind balancer with zero knowledge required by the rest of the system.
Pick one to suit your needs. Service Discovery is not that hard and has been way over engineered.
You would think that the constitution would have included a passage about peoples right to keep and bare armaments being necessary to ensure the country stayed free...
Nah. Lets redefine "arms" to mean "guns", assume for some reason the constitution needed to give the government freedom from itself, and ignore the whole thing as archaic and outdated.
a) Shared data source; each service writes pid/state to a file in the shared data store. It could be a single directory in a single server setup or a dedicated NFS/SMB server for hundreds/thousands of nodes.
b) Pub/Sub service; Kafka, et al, in which services simply subscribe to and publish to a central channel to see everyone else.
c) Determinism; You use predictable naming/addressing and simply infer. This is tricky to scale but not impossible.
d) Any number of stand alone discovery services ala Zookeeper or Eureka. They all end up being effectively the same pub/sub model as B, just prepackaged.
e) You don't discover shit, you have a single load balanced endpoints that can scale out instances as needed behind balancer with zero knowledge required by the rest of the system.
Pick one to suit your needs. Service Discovery is not that hard and has been way over engineered.