public class MicroBlongNode {

public static void main(String[] args) {
    final MicroBlongNode local = new MicroBlongNode("localhost:8888");
    final MicroBlongNode other = new MicroBlongNode("127.0.0.1:8988");
    final String first = "1";
    final String second = "2";

    new Thread(() -> local.propagate(first, other)).start();
    new Thread(() -> other.propagate(second,local)).start();
}

private final String ident;

public MicroBlongNode(String ident) {
    this.ident = ident;
}

public String getIdent() {
    return ident;
}

public synchronized void propagate(String upd, MicroBlongNode backup) {
    System.out.println(ident + ":recvd " + upd + "; backup:" + backup.getIdent());
    this.confirmUpdate(this, upd);
}

public synchronized void confirmUpdate(MicroBlongNode other, String upd) {
    System.out.println(ident + ":recvd confrim" + upd + "; from:" + other.getIdent());
}

}