import java.util.Random;
import org.zeromq.ZMQ.Poller;
import org.zeromq.ZContext;
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.PollItem;
import org.zeromq.ZMQ.Socket;
//Broker peering simulation (part 1)
//Prototypes the state flow
//
public class peering1
{
public static void main(String[] argv)
{
// First argument is this broker's name
// Other arguments are our peers' names
//
if (argv.length < 1) {
System.out.println("syntax: peering1 me {you}\n");
System.exit(-1);
}
String self = argv[0];
System.out.println(String.format("I: preparing broker at %s\n", self));
Random rand = new Random(System.nanoTime());
ZContext ctx = new ZContext();
// Bind state backend to endpoint
Socket statebe = ctx.createSocket(ZMQ.PUB);
statebe.bind(String.format("ipc://%s-state.ipc", self));
// Connect statefe to all peers
Socket statefe = ctx.createSocket(ZMQ.SUB);
statefe.subscribe("".getBytes());
int argn;
for (argn = 1; argn < argv.length; argn++) {
String peer = argv[argn];
System.out.printf("I: connecting to state backend at '%s'\n", peer);
statefe.connect(String.format("ipc://%s-state.ipc", peer));
}
// The main loop sends out status messages to peers, and collects
// status messages back from peers. The zmq_poll timeout defines
// our own heartbeat:
while (true) {
// Poll for activity, or 1 second timeout
PollItem items[] = {new PollItem(statefe, Poller.POLLIN)};
int rc = ZMQ.poll(items, 1000);
if (rc == -1)
break; // Interrupted
// Handle incoming status messages
if (items[0].isReadable()) {
String peer_name = new String(statefe.recv(0));
String available = new String(statefe.recv(0));
System.out.printf("%s - %s workers free\n", peer_name, available);
} else {
// Send random values for worker availability
statebe.send(self, ZMQ.SNDMORE);
statebe.send(String.format("%d", rand.nextInt(10)), 0);
}
}
ctx.destroy();
}
}