The docs says you should copy the other way… If the Windows service is used, the cookie should be copied from C:\Windows\system32\config\systemprofile\.erlang.cookie to the expected location for users running commands like rabbitmqctl.bat. See http://www.rabbitmq.com/cli.html
For what it’s worth, in 2018, the docs are WRONG. In windows 10, the default location of the cookie file appears to be: C:\Windows\System32\config\systemprofile and NOT C:\Windows as the docs say. The best thing to do is to look at the log file, which is typically located in your user %AppData%\Roaming\RabbitMQ\log directory. The log file … Read more
Taking “produce” literally, here is a pretty small one. It doesn’t even read the request (but does fork on every request, so it’s not as minimal possible). -module(hello). -export([start/1]). start(Port) -> spawn(fun () -> {ok, Sock} = gen_tcp:listen(Port, [{active, false}]), loop(Sock) end). loop(Sock) -> {ok, Conn} = gen_tcp:accept(Sock), Handler = spawn(fun () -> handle(Conn) end), … Read more
You have two easy alternatives, use timer:send_interval/2 or erlang:send_after/3. send_interval is easier to setup, while send_after (when used in the Erlang module) is more reliable since it is a built-in function, see the Efficiency Guide. Using send_after also ensures that the gen_server process is not overloaded. If you were using the send_interval function you would … Read more
It’s a mistake to think of parallelism as only about raw number crunching power. Erlang is closer to the way a cluster computer works than, say, a GPU or classic supercomputer. In modern GPUs and old-style supercomputers, performance is all about vectorized arithmetic, special-purpose calculation hardware, and low-latency communication between processing units. Because communication latency … Read more
Chicago Boss: Routes does not work in production mode?
1- Set environment variable: Variable name : ERLANG_HOME Variable value: C:\Program Files (x86)\erl6.4 note: don’t include bin on above step. 2- Add %ERLANG_HOME%\bin to the PATH environmental variable: Variable name : PATH Variable value: %ERLANG_HOME%\bin This works well.
If you have enough RAM it’s not too hard to handle 1M or more connections on linux. These guys handled 10 million connections with a java application on a single box using regular CentOS kernel with a few sysctl tweaks: sysctl -w fs.file-max=12000500 sysctl -w fs.nr_open=20000500 ulimit -n 20000000 sysctl -w net.ipv4.tcp_mem=’10000000 10000000 10000000′ sysctl … Read more
I had a similar problem years ago. What you are trying to do is remove an offline node, which as far as I am aware was impossible in earlier versions of mnesia. You can however connect to the cluster using a dummy node named bad@node, and started with a tweaked system.config of the original clustered … Read more
Yes but it is painful. Below is a “lambda function declaration” (aka fun in Erlang terms). 1> F=fun(X) -> X+2 end. %%⇒ #Fun <erl_eval.6.13229925> Have a look at this post. You can even enter a module’s worth of declaration if you ever needed. In other words, yes you can declare functions.