put pingtask is in a seperate thread pool

agent/src/com/cloud/agent/Agent.java

@@ -28,6 +28,10 @@ import java.util.List;
 import java.util.Map;
 import java.util.Timer;
 import java.util.TimerTask;
+
+import java.util.concurrent.SynchronousQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import javax.naming.ConfigurationException;
@@ -52,6 +56,7 @@ import com.cloud.exception.AgentControlChannelException;
 import com.cloud.resource.ServerResource;
 import com.cloud.utils.PropertiesUtil;
 import com.cloud.utils.backoff.BackoffAlgorithm;
+import com.cloud.utils.concurrency.NamedThreadFactory;
 import com.cloud.utils.exception.CloudRuntimeException;
 import com.cloud.utils.nio.HandlerFactory;
 import com.cloud.utils.nio.Link;
@@ -112,6 +117,8 @@ public class Agent implements HandlerFactory, IAgentControl {
 
     StartupTask                 _startup              = null;
     boolean                     _reconnectAllowed     = true;
+    //For time sentitive task, e.g. PingTask
+    private ThreadPoolExecutor     _ugentTaskPool;
 
     // for simulator use only
     public Agent(IAgentShell shell) {
@@ -121,6 +128,10 @@ public class Agent implements HandlerFactory, IAgentControl {
         _connection = new NioClient("Agent", _shell.getHost(), _shell.getPort(), _shell.getWorkers(), this);
 
         Runtime.getRuntime().addShutdownHook(new ShutdownThread(this));
+        
+        _ugentTaskPool = new ThreadPoolExecutor(shell.getPingRetries(), 2 * shell.getPingRetries(), 10, TimeUnit.MINUTES, 
+                                                new SynchronousQueue<Runnable>(), new NamedThreadFactory("UgentTask")
+                                                );
     }
 
     public Agent(IAgentShell shell, int localAgentId, ServerResource resource) throws ConfigurationException {
@@ -152,6 +163,10 @@ public class Agent implements HandlerFactory, IAgentControl {
         s_logger.debug("Adding shutdown hook");
         Runtime.getRuntime().addShutdownHook(new ShutdownThread(this));
 
+        _ugentTaskPool = new ThreadPoolExecutor(shell.getPingRetries(), 2 * shell.getPingRetries(), 10, TimeUnit.MINUTES, 
+                                                new SynchronousQueue<Runnable>(), new NamedThreadFactory("UgentTask")
+                                                );
+        
         s_logger.info("Agent [id = " + (_id != null ? _id : "new") + " : type = " + getResourceName() + " : zone = " + _shell.getZone() + " : pod = " + _shell.getPod() + " : workers = "
                 + _shell.getWorkers() + " : host = " + _shell.getHost() + " : port = " + _shell.getPort());
     }
@@ -246,6 +261,8 @@ public class Agent implements HandlerFactory, IAgentControl {
             _resource.stop();
             _resource = null;
         }
+        
+        _ugentTaskPool.shutdownNow();
     }
 
     public Long getId() {
@@ -414,6 +431,9 @@ public class Agent implements HandlerFactory, IAgentControl {
 
         setLastPingResponseTime();
         scheduleWatch(link, response, _pingInterval, _pingInterval);
+      
+        _ugentTaskPool.setKeepAliveTime(2* _pingInterval, TimeUnit.MILLISECONDS);
+        
         s_logger.info("Startup Response Received: agent id = " + getId());
     }
 
@@ -728,7 +748,11 @@ public class Agent implements HandlerFactory, IAgentControl {
                 s_logger.trace("Scheduling " + (_request instanceof Response ? "Ping" : "Watch Task"));
             }
             try {
-                _link.schedule(new ServerHandler(Task.Type.OTHER, _link, _request));
+                if (_request instanceof Response) {
+                    _ugentTaskPool.submit(new ServerHandler(Task.Type.OTHER, _link, _request));
+                } else {
+                    _link.schedule(new ServerHandler(Task.Type.OTHER, _link, _request));
+                }
             } catch (final ClosedChannelException e) {
                 s_logger.warn("Unable to schedule task because channel is closed");
             }