One thing to realise is that the Erlang concurrency model does NOT really specify that the data in messages must be copied between processes, it states that sending messages is the only way to communicate and that there is no shared state. As all data is immutable, which is fundamental, then an implementation may very … Read more
There’s also integer_to_list/1, which does exactly what you want, without the ugliness.
In your original code, you only started one MailboxProcessor. Make wait() a function, and call it with each yield. Also you are not waiting for them to spin up or receive the messages, which I think invalidates the timing info; see my code below. That said, I have some success; on my box I can … Read more
Atoms are literals, constants with their own name for value. What you see is what you get and don’t expect more. The atom cat means “cat” and that’s it. You can’t play with it, you can’t change it, you can’t smash it to pieces; it’s cat. Deal with it. I compared atoms to constants having … Read more
Erlang has been designed for concurrent, fault-tolerant communication systems. You can easily write servers that handle large number of network connections and (thanks to one garbage collector per Erlang process) the servers can retain soft real-time characteristics (i.e., the whole server is not paused until GC finishes). You can also hot-swap Erlang code, distribute it … Read more
Repeat after me: “These are different paradigms” Say that aloud 20 times or so — it is our mantra for the moment. If we really must compare apples and oranges, let’s at least consider where the common aspects of “being fruit” intersect. Java “objects” are a Java programmer’s basic unit of computation. That is, an … Read more
I had this same problem today. There were no cookie or firewall problems and windows reported that the service was running successfully. This is what finally fixed it: Run RabbitMQ sbin command prompt as administrator. Run “rabbitmq-service remove” Run “rabbitmq-service install” For some reason the service set up by the installer did not configure several … Read more
This is related to a previous question, if not exactly the same! It’s not such a simple question because the actor model of concurrency allows for many different types of applications to be built, from a stateful single-VM application (with a few separate actor classes) to a stateless cluster of thousands of instances of an … Read more
It’s applicable everywhere. Whether or not you write your software in a “let it crash” pattern, it will crash anyway, e.g., when hardware fails. “Let it crash” applies anywhere where you need to withstand reality. Quoth James Hamilton: If a hardware failure requires any immediate administrative action, the service simply won’t scale cost-effectively and reliably. … Read more
The basic steps of tracing for function calls are on a non-live node: > dbg:start(). % start dbg > dbg:tracer(). % start a simple tracer process > dbg:tp(Module, Function, Arity, []). % specify MFA you are interested in > dbg:p(all, c). % trace calls (c) of that MFA for all processes. … trace here > … Read more