Start Elastic Node without network link, closes #842.

modules/elasticsearch/src/main/java/org/elasticsearch/discovery/zen/ping/multicast/MulticastZenPing.java

@@ -36,7 +36,6 @@ import org.elasticsearch.common.io.stream.VoidStreamable;
 import org.elasticsearch.common.network.NetworkService;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
-import org.elasticsearch.discovery.DiscoveryException;
 import org.elasticsearch.discovery.zen.DiscoveryNodesProvider;
 import org.elasticsearch.discovery.zen.ping.ZenPing;
 import org.elasticsearch.discovery.zen.ping.ZenPingException;
@@ -142,9 +141,14 @@ public class MulticastZenPing extends AbstractLifecycleComponent<ZenPing> implem
             this.datagramPacketReceive = new DatagramPacket(new byte[bufferSize], bufferSize);
             this.datagramPacketSend = new DatagramPacket(new byte[bufferSize], bufferSize, InetAddress.getByName(group), port);
         } catch (Exception e) {
-            throw new DiscoveryException("Failed to set datagram packets", e);
+            logger.warn("disabled, failed to setup multicast (datagram) discovery : {}", e.getMessage());
+            if (logger.isDebugEnabled()) {
+                logger.debug("disabled, failed to setup multicast (datagram) discovery", e);
+            }
+            return;
         }
 
+        InetAddress multicastInterface = null;
         try {
             MulticastSocket multicastSocket;
 //            if (NetworkUtils.canBindToMcastAddress()) {
@@ -161,7 +165,7 @@ public class MulticastZenPing extends AbstractLifecycleComponent<ZenPing> implem
             multicastSocket.setTimeToLive(ttl);
 
             // set the send interface
-            InetAddress multicastInterface = networkService.resolvePublishHostAddress(address);
+            multicastInterface = networkService.resolvePublishHostAddress(address);
             multicastSocket.setInterface(multicastInterface);
             multicastSocket.joinGroup(InetAddress.getByName(group));
 
@@ -170,19 +174,35 @@ public class MulticastZenPing extends AbstractLifecycleComponent<ZenPing> implem
             multicastSocket.setSoTimeout(60000);
 
             this.multicastSocket = multicastSocket;
-        } catch (Exception e) {
-            throw new DiscoveryException("Failed to setup multicast socket", e);
-        }
 
-        this.receiver = new Receiver();
+            this.receiver = new Receiver();
-        this.receiverThread = daemonThreadFactory(settings, "discovery#multicast#received").newThread(receiver);
+            this.receiverThread = daemonThreadFactory(settings, "discovery#multicast#receiver").newThread(receiver);
-        this.receiverThread.start();
+            this.receiverThread.start();
+        } catch (Exception e) {
+            datagramPacketReceive = null;
+            datagramPacketSend = null;
+            if (multicastSocket != null) {
+                multicastSocket.close();
+                multicastSocket = null;
+            }
+            logger.warn("disabled, failed to setup multicast discovery on {}: {}", multicastInterface, e.getMessage());
+            if (logger.isDebugEnabled()) {
+                logger.debug("disabled, failed to setup multicast discovery on {}", e, multicastInterface);
+            }
+        }
     }
 
     @Override protected void doStop() throws ElasticSearchException {
-        receiver.stop();
+        if (receiver != null) {
-        receiverThread.interrupt();
+            receiver.stop();
-        multicastSocket.close();
+        }
+        if (receiverThread != null) {
+            receiverThread.interrupt();
+        }
+        if (multicastSocket != null) {
+            multicastSocket.close();
+            multicastSocket = null;
+        }
     }
 
     @Override protected void doClose() throws ElasticSearchException {
@@ -229,6 +249,9 @@ public class MulticastZenPing extends AbstractLifecycleComponent<ZenPing> implem
     }
 
     private void sendPingRequest(int id, boolean remove) {
+        if (multicastSocket == null) {
+            return;
+        }
         synchronized (sendMutex) {
             CachedStreamOutput.Entry cachedEntry = CachedStreamOutput.popEntry();
             try {