Start work on a little spit and polish, with cleaner exceptions.

proxy/src/main/java/net/md_5/bungee/BungeeServerInfo.java

@@ -1,6 +1,9 @@
 package net.md_5.bungee;
 
 import io.netty.bootstrap.Bootstrap;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelOption;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import java.net.InetSocketAddress;
 import java.util.Queue;
@@ -48,8 +51,20 @@ public class BungeeServerInfo extends ServerInfo
                 .channel( NioSocketChannel.class )
                 .group( BungeeCord.getInstance().eventLoops )
                 .handler( PipelineUtils.BASE )
+                .option( ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000 ) // TODO: Configurable
                 .remoteAddress( getAddress() )
                 .connect()
-                .channel().pipeline().get( HandlerBoss.class ).setHandler( new PingHandler( callback ) );
+                .addListener( new ChannelFutureListener()
+        {
+            @Override
+            public void operationComplete(ChannelFuture future) throws Exception
+            {
+                if ( !future.isSuccess() )
+                {
+                    callback.done( null, future.cause() );
+                }
+            }
+        } )
+                .channel().pipeline().get( HandlerBoss.class ).setHandler( new PingHandler( this, callback ) );
     }
 }

proxy/src/main/java/net/md_5/bungee/ServerConnector.java

@@ -99,7 +99,7 @@ public class ServerConnector extends PacketHandler
             target.addPlayer( user );
 
             user.setServer( server );
-            ch.pipeline().get( HandlerBoss.class ).setHandler( new DownstreamBridge( bungee, user ) );
+            ch.pipeline().get( HandlerBoss.class ).setHandler( new DownstreamBridge( bungee, user, server ) );
         }
 
         thisState = State.FINISHED;
@@ -119,4 +119,10 @@ public class ServerConnector extends PacketHandler
     {
         throw new KickException( kick.message );
     }
+
+    @Override
+    public String toString()
+    {
+        return "[" + user.getName() + "] <-> ServerConnector [" + target.getName() + "]";
+    }
 }

proxy/src/main/java/net/md_5/bungee/UserConnection.java

@@ -7,6 +7,7 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import java.net.InetSocketAddress;
 import java.util.Collection;
@@ -114,6 +115,7 @@ public final class UserConnection implements ProxiedPlayer
                 ch.pipeline().get( HandlerBoss.class ).setHandler( new ServerConnector( bungee, UserConnection.this, target ) );
             }
         } )
+                .option( ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000 ) // TODO: Configurable
                 .remoteAddress( target.getAddress() )
                 .connect().addListener( new ChannelFutureListener()
         {
@@ -128,6 +130,9 @@ public final class UserConnection implements ProxiedPlayer
                     {
                         sendMessage( ChatColor.RED + "Could not connect to target server, you have been moved to the default server" );
                         connect( def, false );
+                    } else
+                    {
+                        disconnect( "Server down, could not connect to default!" );
                     }
                 }
             }

proxy/src/main/java/net/md_5/bungee/connection/DownstreamBridge.java

@@ -11,6 +11,7 @@ import net.md_5.bungee.Util;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.config.ServerInfo;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
+import net.md_5.bungee.api.connection.Server;
 import net.md_5.bungee.api.event.ChatEvent;
 import net.md_5.bungee.api.event.PluginMessageEvent;
 import net.md_5.bungee.packet.Packet0KeepAlive;
@@ -26,6 +27,7 @@ public class DownstreamBridge extends PacketHandler
 
     private final ProxyServer bungee;
     private final UserConnection con;
+    private final Server server;
 
     @Override
     public void handle(ByteBuf buf) throws Exception
@@ -196,4 +198,10 @@ public class DownstreamBridge extends PacketHandler
         con.disconnect( "[Kicked] " + kick.message );
         throw new CancelSendSignal();
     }
+
+    @Override
+    public String toString()
+    {
+        return "[" + con.getName() + "] <-> DownstreamBridge <-> [" + server.getInfo().getName() + "]";
+    }
 }

proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java

@@ -240,4 +240,10 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     {
         return (InetSocketAddress) ch.remoteAddress();
     }
+
+    @Override
+    public String toString()
+    {
+        return "[" + ( ( getName() != null ) ? getName() : getAddress() ) + "] <-> InitialHandler";
+    }
 }

proxy/src/main/java/net/md_5/bungee/connection/PingHandler.java

@@ -6,6 +6,7 @@ import io.netty.channel.Channel;
 import lombok.RequiredArgsConstructor;
 import net.md_5.bungee.api.Callback;
 import net.md_5.bungee.api.ServerPing;
+import net.md_5.bungee.api.config.ServerInfo;
 import net.md_5.bungee.packet.PacketFFKick;
 import net.md_5.bungee.packet.PacketHandler;
 
@@ -13,6 +14,7 @@ import net.md_5.bungee.packet.PacketHandler;
 public class PingHandler extends PacketHandler
 {
 
+    private final ServerInfo target;
     private final Callback<ServerPing> callback;
     private static final ByteBuf pingBuf = Unpooled.wrappedBuffer( new byte[]
     {
@@ -38,4 +40,10 @@ public class PingHandler extends PacketHandler
         ServerPing ping = new ServerPing( Byte.parseByte( split[1] ), split[2], split[3], Integer.parseInt( split[4] ), Integer.parseInt( split[5] ) );
         callback.done( ping, null );
     }
+
+    @Override
+    public String toString()
+    {
+        return "[Ping Handler] -> " + target.getName();
+    }
 }

proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java

@@ -75,4 +75,10 @@ public class UpstreamBridge extends PacketHandler
             throw new CancelSendSignal();
         }
     }
+
+    @Override
+    public String toString()
+    {
+        return "[" + con.getName() + "] -> UpstreamBridge";
+    }
 }

proxy/src/main/java/net/md_5/bungee/netty/HandlerBoss.java

@@ -4,6 +4,9 @@ import com.google.common.base.Preconditions;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundMessageHandlerAdapter;
+import io.netty.handler.timeout.ReadTimeoutException;
+import java.util.logging.Level;
+import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.connection.CancelSendSignal;
 import net.md_5.bungee.packet.DefinedPacket;
 import net.md_5.bungee.packet.PacketHandler;
@@ -30,6 +33,7 @@ public class HandlerBoss extends ChannelInboundMessageHandlerAdapter<ByteBuf>
         if ( handler != null )
         {
             handler.connected( ctx.channel() );
+            ProxyServer.getInstance().getLogger().log( Level.INFO, "{0} has connected", handler );
         }
     }
 
@@ -38,6 +42,7 @@ public class HandlerBoss extends ChannelInboundMessageHandlerAdapter<ByteBuf>
     {
         if ( handler != null )
         {
+            ProxyServer.getInstance().getLogger().log( Level.INFO, "{0} has disconnected", handler );
             handler.disconnected( ctx.channel() );
         }
     }
@@ -69,9 +74,15 @@ public class HandlerBoss extends ChannelInboundMessageHandlerAdapter<ByteBuf>
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception
     {
-        cause.printStackTrace();
         if ( ctx.channel().isActive() )
         {
+            if ( cause instanceof ReadTimeoutException )
+            {
+                ProxyServer.getInstance().getLogger().log( Level.WARNING, handler + " - read timed out" );
+            } else
+            {
+                ProxyServer.getInstance().getLogger().log( Level.SEVERE, handler + " - encountered exception", cause );
+            }
             ctx.close();
         }
     }

proxy/src/main/java/net/md_5/bungee/packet/PacketHandler.java

@@ -6,6 +6,9 @@ import io.netty.channel.Channel;
 public abstract class PacketHandler
 {
 
+    @Override
+    public abstract String toString();
+
     public void connected(Channel channel) throws Exception
     {
     }

proxy/src/main/java/net/md_5/bungee/tablist/GlobalTabList.java

@@ -22,7 +22,7 @@ public class GlobalTabList implements TabListHandler
         UserConnection con = (UserConnection) player;
         for ( ProxiedPlayer p : ProxyServer.getInstance().getPlayers() )
         {
-            con.packetQueue.add( new PacketC9PlayerListItem( p.getDisplayName(), true, p.getPing() ) );
+            con.sendPacket(new PacketC9PlayerListItem( p.getDisplayName(), true, p.getPing() ) );
         }
         BungeeCord.getInstance().broadcast( new PacketC9PlayerListItem( player.getDisplayName(), true, player.getPing() ) );
     }

proxy/src/main/java/net/md_5/bungee/tablist/ServerUniqueTabList.java

@@ -40,7 +40,7 @@ public class ServerUniqueTabList implements TabListHandler
             {
                 for ( String username : usernames )
                 {
-                    ( (UserConnection) player ).packetQueue.add( new PacketC9PlayerListItem( username, false, 9999 ) );
+                    ( (UserConnection) player ).sendPacket(new PacketC9PlayerListItem( username, false, 9999 ) );
                 }
                 usernames.clear();
             }