在分布式Erlang中发送大消息的性能特征是什么？ [英] What are the performance characteristics of sending big messages in Distributed Erlang?

问题描述

假设我在Erlang应用程序中创建了新的本地进程，并且想向它发送一条大消息。

Suppose I create new local process in an Erlang application, and i want to send to it a big message.

-module(chain_hello). 

start(N, Some_big_data)->                                    
   Pid1 = spawn(chain_hello, some_fun, [N]),
   Pid1 ! Some_big_data,
   io:format("done \n").

尽管 Some_big_data 是对大数据的引用数据（例如文件内容）-发送时是否复制？

despite Some_big_data is a reference to really big data (eg. content of a file) - is it copied when sending? Are there big penalties for performance?

通常我会使用一些线程安全的共享对象（和/或互斥锁）。

Normally I would use some thread safe shared object (and/or mutex). Is there any solution in Erlang to avoid copying message content?

添加：

有趣的情况是Some_big_data是结构化内容-具体来说是：地图，我可以在上面执行一些操作。

ADDED:
Interesting case is when Some_big_data is structured content - to be specific: map, on which I can perform some operations.

ADDED2

我看到Erlang没有这样的解决方案（由于在Erlang中进行了设计，因此在工作进程中共享了一些结构化的数据，例如map）。但是我认为通过扎实的工作和轻松的并发管理是有道理的。

ADDED2
Ok, I see there is no such solution for Erlang (sharing some structured data like map in worker process) - because of Erlang design. But I think it is justified by solid work, and easily concurrence management.

推荐答案

作为建议，您只能将当前进程的pid（self（））发送到所需的进程处理some_big_data。这样，当您要使用some_big_data时，可以从第二个过程中将其引用回去。

As a suggestion, you can send only the pid of the current process (self()) to the process that you want to handle that some_big_data. That way, when you want to use that some_big_data, you can reference it back to it from the 2nd process.

例如：

-module(proc1).

send_big_data() ->
  BigData = get_some_big_data(),
  Pid = spawn(fun proc2:start/0),
  Pid ! {process_big_data, self()},
  loop(Pid, BigData).

loop(Pid,BigData) ->
  receive
    get_first_element ->
      [H|T] = BigData,
      Pid ! {response, H};
    _ ->
      Pid ! {nothing}
   end,
   loop(Pid).

（很抱歉出现语法错误）。

(Sorry for the eventual syntax mistakes).

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