TEIIDDES-1971: Workaround for avoiding annoying errors in server log

* "Connection reset by peer" messages appear in the jboss log due to making
  a socket connection from the host heatbeat requests but never using the
  socket. Almost like the server is upset that we connected then closed!!

* The read socket stream normally returns the hostname of the server so
  this is logged along with a nice message, ensuring the socket is used
  before closing it.

* The successfully connected message is useful for debug purposes but is
  unnecessary for users so implements tracing for the plugin in order to
  only log the messages in debug mode.

plugins/org.teiid.designer.dqp/.options

@@ -0,0 +1,17 @@
+# Master debug switch for plugin
+org.teiid.designer.dqp/debug = false
+
+# Option indicating if a trace message should be logged when a preview job is asked if it should run.
+org.teiid.designer.dqp/debug/preview/jobs/jobShouldRun = false
+
+# Option indicating if a trace message should be logged when a preview job is started.
+org.teiid.designer.dqp/debug/preview/jobs/jobStart = false
+
+# Option indicating if a trace message should be logged when a preview job is finished running.
+org.teiid.designer.dqp/debug/preview/jobs/jobDone = false
+
+# Option indicating if a trace message should be logged for how long a preview job took to run.
+org.teiid.designer.dqp/debug/preview/jobs/jobDuration = false
+
+# Option indicating if a trace message should be logged for the jboss host connection check 
+org.teiid.designer.dqp/debug/jboss/connection = false

plugins/org.teiid.designer.dqp/src/org/teiid/designer/runtime/DebugConstants.java

@@ -52,4 +52,8 @@ public interface DebugConstants {
      */
     String PREVIEW_JOB_DURATION = PREVIEW_JOBS + "/jobDuration"; //$NON-NLS-1$
 
+    /**
+     *  Option indicating if a trace message should be logged for the jboss host connection check 
+     */
+    String JBOSS_CONNECTION = DEBUG + "/jboss/connection"; //$NON-NLS-1$
 }

plugins/org.teiid.designer.dqp/src/org/teiid/designer/runtime/adapter/JBossServerUtil.java

@@ -7,11 +7,16 @@
 */
 package org.teiid.designer.runtime.adapter;
 
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
 import java.net.InetSocketAddress;
 import java.net.Socket;
 import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
 import org.eclipse.wst.server.core.IServer;
 import org.jboss.ide.eclipse.as.core.server.internal.JBossServer;
+import org.teiid.designer.runtime.DebugConstants;
 import org.teiid.designer.runtime.DqpPlugin;
 
 /**
@@ -43,6 +48,7 @@ public static boolean isJBossServerConnected(IServer parentServer, JBossServer j
      */
     protected static boolean isHostConnected(String host, int port) throws Exception {
         Socket socket = null;
+        Reader in  = null;
         InetSocketAddress endPoint = new InetSocketAddress(host, port);
 
         if (endPoint.isUnresolved()) {
@@ -54,11 +60,68 @@ protected static boolean isHostConnected(String host, int port) throws Exception
             socket = new Socket();
             socket.connect(endPoint, 1024);
 
+            /*
+             * This may not seem necessary since a socket connection
+             * should be enough. However, TEIIDDES-1971 has shown
+             * that without actually using the socket, 'Connection reset
+             * by peer' messages with be reported in the server log.
+             */
+            InputStream socketReader = socket.getInputStream();
+
+            final char[] buffer = new char[100];
+            in = new InputStreamReader(socketReader);
+            int rsz = in.read(buffer, 0, buffer.length);
+            if (rsz == -1) {
+                if (DqpPlugin.getInstance().isDebugOptionEnabled(DebugConstants.JBOSS_CONNECTION)) {
+                    /*
+                     * Only need to log this with debug tracing turned on.
+                     */
+                    String message = DqpPlugin.Util.getString("jbossServerConnectionStreamEmpty", host, port); //$NON-NLS-1$
+                    IStatus status = new Status(IStatus.OK, DqpPlugin.PLUGIN_ID, message);
+                    DqpPlugin.Util.log(status);
+                }
+                return false;
+            }
+
+            StringBuffer output = new StringBuffer();
+            for (int i = 0; i < buffer.length; ++i) {
+                if (Character.isLetterOrDigit(buffer[i])) {
+                    output.append(buffer[i]);
+                }
+            }
+
+            if (DqpPlugin.getInstance().isDebugOptionEnabled(DebugConstants.JBOSS_CONNECTION)) {
+                /*
+                 * Only need to log this with debug tracing turned on.
+                 */
+                String message = DqpPlugin.Util.getString("jbossServerHeartBeat", host, port, output); //$NON-NLS-1$
+                IStatus status = new Status(IStatus.OK, DqpPlugin.PLUGIN_ID, message);
+                DqpPlugin.Util.log(status);
+            }
+
             return true;
+        } catch (Exception ex) {
+            if (DqpPlugin.getInstance().isDebugOptionEnabled(DebugConstants.JBOSS_CONNECTION)) {
+                /*
+                 * Only need to log this with debug tracing turned on.
+                 */
+                DqpPlugin.Util.log(ex);
+            }
+            return false;
         } finally {
-            if (socket != null && socket.isConnected()) {
-                socket.close();
-                socket = null;
+            try {
+                if (in != null)
+                    in.close();
+
+                if (socket != null && socket.isConnected()) {
+                    socket.close();
+                    socket = null;
+                }
+            } catch (Exception ex2) {
+                /*
+                 * Unlikely event that socket did not close correctly.
+                 */
+                DqpPlugin.Util.log(ex2);
             }
         }
     }

plugins/org.teiid.designer.dqp/src/org/teiid/designer/runtime/i18n.properties

@@ -136,6 +136,8 @@ jdbcInfoType = JDBC
 # TeiidServerAdapterUtil
 jbossServerNotStartedMessage = No Teiid Instance found (server not started)
 jbossServerConnectionFailureMessage = Failed to connect to the jboss server at {0}
+jbossServerConnectionStreamEmpty = The Jboss Server on {0}\:{1} returned an empty stream
+jbossServerHeartBeat = A Jboss Server on {0}\:{1} correctly answered a host-available request with "{2}"
 
 # OrphanedTeiidServerException
 OrphanedTeiidServerException.message = The Teiid Instance {0} does not have a parent jboss server