Jinterface OtpNode initialization -name or -sname flag

Question

When creating an OtpNode instance what kind of node is this? Is it like an erl -sname xxx or like an elr -name xxx ?

I mean when I do: OtpNode node = new OtpNode(nodeName, cookie) then this is equivalent to creating an erlang node with -sname nodeName or with -name nodeName? — Paralife, Oct 20 '09 at 13:25

score 2 · Answer 1 · answered Oct 20 '09 at 16:42

It is working as "-sname". At least according to the following example.

TryOTP.java (imports are omitted on purpose)

public class TryOTP {
    public void start() {
        OtpNode node = null;

        try {
            node = new OtpNode("javambox@localhost", "zed"); // name, cookie
        } catch (IOException ex) {
            System.exit(-1);
        }

        System.out.println("Connected to epmd...");

        if (node.ping("shell@localhost", 2000)) {
            System.out.println("shell@localhost is up.");
        } else {
            System.out.println("shell@localhost is down");
        }

        OtpMbox mbox = node.createMbox("mbox");

        while (true) {

            OtpErlangObject o = null;
            try {
                o = mbox.receive();
            } catch (OtpErlangDecodeException ex) {
                System.out.println("Received message could not be decoded: " + ex);
                continue;
            } catch (OtpErlangExit ex) {
                System.out.println("Remote pid " + ex.pid() + " has terminated.");
                continue;
            }
            System.out.println("Received: " + o);
        }
    }

    public static void main(String[] args)
    {
        System.getProperties().setProperty("OtpConnection.trace", "3");
        new TryOTP().start();
    }

}

Running the Erlang shell:

erl -sname shell@localhost -setcookie zed

(shell@localhost)1> net_adm:ping(javambox@localhost).
pong
(shell@localhost)2> {mbox, javambox@localhost} ! hello. 
hello

Thanks. So if I suppose that if i do OtpNode("javaMbox@myhost.mydomain.com", "cookie") then it would be equivalent to -name. Well, I doesnt. If i start erl -name the two of them do not work. In fact java node still thinks it is an "sname" node. How can I make java OtpNode instance behave as an erl -name node? — Paralife, Oct 21 '09 at 09:07

score 1 · Answer 2 · answered Nov 17 '09 at 09:57

From the Java code you can connect to Erlang nodes started with both -name and -sname. It is only in the other direction that it's tricky (and I don't have the answer to that). So if you can do the connection from the Java side, then the problem is solved.

Jinterface OtpNode initialization -name or -sname flag

2 Answers2