1 Reply Latest reply on Sep 20, 2005 2:28 PM by Tao Xie

    Weird problem in JNDI. JNDI client always try to connect one

    Tao Xie Newbie

      My environment,
      JBoss 4.0.2. In the LAN, there is a JBoss 4.0.2 instance running on Linux box - 10.2.3.172 . My machine (WinXP)'s IP address is 10.2.3.195

      I used 10.2.3.172 for some testing, but no longer use it. and it is still up & running for other purpose.

      I have a simple JNDI client, whatever URL I give, even non-exist ones, it always try to connect to 10.2.3.172. So strange.

      I don't have jndi.properties.

      Here is the TCP sniffer says,

      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=1640 Ack=15567 Win=65535 Len=17
      10.2.3.195 10.2.3.255 NBNS Name query NB ASDFA<00>
      10.2.3.195 10.2.7.5 TCP 3389 > 4215 [PSH, ACK] Seq=15567 Ack=1657 Win=65309 Len=16
      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=1657 Ack=15567 Win=65535 Len=52
      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=1709 Ack=15583 Win=65519 Len=59
      10.2.3.195 10.2.7.5 TCP 3389 > 4215 [ACK] Seq=15583 Ack=1768 Win=65198 Len=0
      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=1768 Ack=15583 Win=65519 Len=94
      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=1862 Ack=15583 Win=65519 Len=108
      10.2.3.195 10.2.7.5 TCP 3389 > 4215 [ACK] Seq=15583 Ack=1970 Win=64996 Len=0
      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=1970 Ack=15583 Win=65519 Len=24
      10.2.3.195 10.2.7.5 TCP 3389 > 4215 [PSH, ACK] Seq=15583 Ack=1994 Win=64972 Len=348
      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=1994 Ack=15931 Win=65171 Len=94
      10.2.3.195 230.0.0.4 IGMP V2 Membership Report
      10.2.3.195 230.0.0.4 UDP Source port: 2506 Destination port: 1102
      10.2.3.172 Broadcast ARP Who has 10.2.3.195? Tell 10.2.3.172
      10.2.3.195 10.2.3.172 ARP 10.2.3.195 is at 00:0c:f1:ea:e0:ec
      10.2.3.172 10.2.3.195 UDP Source port: 1102 Destination port: 2506
      10.2.3.195 10.2.3.172 TCP 2507 > 1100 [SYN] Seq=0 Ack=0 Win=65535 Len=0 MSS=1460
      10.2.3.172 10.2.3.195 TCP 1100 > 2507 [SYN, ACK] Seq=0 Ack=1 Win=5840 Len=0 MSS=1460
      10.2.3.195 10.2.3.172 TCP 2507 > 1100 [ACK] Seq=1 Ack=1 Win=65535 Len=0
      10.2.3.172 10.2.3.195 TCP 1100 > 2507 [PSH, ACK] Seq=1 Ack=1 Win=5840 Len=4
      10.2.3.172 10.2.3.195 TCP 1100 > 2507 [FIN, PSH, ACK] Seq=5 Ack=1 Win=5840 Len=968
      10.2.3.195 10.2.3.172 TCP 2507 > 1100 [ACK] Seq=1 Ack=974 Win=64563 Len=0
      10.2.7.5 10.2.3.195 TCP 4215 > 3389 [PSH, ACK] Seq=2088 Ack=15931 Win=65171 Len=101
      10.2.3.195 10.2.7.5 TCP 3389 > 4215 [ACK] Seq=15931 Ack=2189 Win=64777 Len=0
      10.2.3.195 10.2.3.172 TCP 2508 > 44173 [SYN] Seq=0 Ack=0 Win=65535 Len=0 MSS=1460

      "ASDFA" is the given non-existant URL by intention.
      10.2.3.172 Broadcast ARP Who has 10.2.3.195? Tell 10.2.3.172
      Somehow, 10.2.3.172 broadcast a message asking for the MAC address of 10.2.3.195. How is it possible?
      After that, they are happliy talk to each other.

      My JNDIClient...


      package test;

      import javax.naming.Context;
      import javax.naming.InitialContext;
      import javax.naming.NamingException;
      import java.util.Hashtable;

      /**
      * Test Program to reproduce Bug 6050
      */
      public class JNDIClient {

      public static void main(String[] args) {
      if (args.length < 2) {
      usage();
      return;
      }
      String url = args[0];
      String objName = args[1];
      try {
      InitialContext ic = getInitialContext(url);
      if (ic != null) {
      log("Successfully get Initial Context " + ic.toString() + " from URL " + url);
      Object obj = ic.lookup(objName);
      if (ic != null) {
      log("Sucessfully found object " + obj);
      }
      }
      else {
      log("Failed to get Initial Context");
      }
      } catch (Exception e) {
      log("Failure with exception ...");
      e.printStackTrace();
      }
      }
      public static InitialContext getInitialContext(String url) throws NamingException {
      Hashtable env = new Hashtable();
      env.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
      env.put(Context.PROVIDER_URL, "jnp://" + url);
      // env.put("java.naming.factory.url.pkgs", "org.jboss.naming:org.jnp.interfaces");
      InitialContext ctx = new InitialContext(env);
      return ctx;
      }

      public static void usage() {
      log("java test.JNDIClient (i.e. thrush:1099) (i.e. ejb/RDSAccessFacade");
      log("");
      }
      public static void log(String s) {
      System.out.println(s);
      }
      }

        • 1. Re: Weird problem in JNDI. JNDI client always try to connect
          Tao Xie Newbie

          just update on this.
          The weird behavior is caused by the jnp multicast discovery.
          Setting "jnp.disableDiscovery" to "true" solved the problem.

          But the othe problem still there in

          new InitialContext(env)

          If, the given URL is not reachable. I expect to see CommunicationException, just like Weblogic does.
          However, jnp just silently return an InitialContext object which is not usable.