主管和工作进程是否应该注册为全局？ -二郎

Question

我刚开始学习 Erlang 一个月，很想知道在单例进程中是否应该将 supervisor 模块和 worker 模块都注册为全局？

Answer 1

You don't "register" a module as global, you don't register a module at all. If a module is loaded on a node then any other module evaluated in any process on that node can call functions in the original module. No registering or importing or anything else necessary.

If you mean registering a process as global then it depends which nodes are are expected to be able to find the process. If it is only to be reached from the same node the a local register/2 is enough. If, however, you want it to be globally accessible then you need to register it on all nodes which you typically do using the global module and with the {global,Name} argument when starting supervisors and behaviours.

EDIT:

OK, the only processes that really needs to be globally registered are the ones that you need to be globally accessible, which in this case is probably only the worker process. The supervisor probably needs only local registering, if any at all.

Note that registering the supervisor, either locally or globally, will NOT by default register the worker process even if it is its child. You have to explicitly register each process.

Answer 2

The rule is simple: you should register the process you are going to communicate with by name.

If you are going to communicate with supervisor, then you have to register supervisor. If you are going to communicate with worker - you should register worker.

In my practice I had to register workers more often, and only had to register supervisors implementing simple_one_for_one strategy that were used as process factories