Cleanup of worker VMs left over from previous session in a reliable way

server/src/com/cloud/agent/manager/AgentManagerImpl.java

@@ -612,7 +612,8 @@ public class AgentManagerImpl implements AgentManager, HandlerFactory,
 
 		Hypervisor.HypervisorType hypervisorType = Hypervisor.HypervisorType.getType(cmd.getHypervisor());
 		if (hypervisorType == null) {
-			throw new InvalidParameterValueException("Please specify a valid hypervisor name");
+			s_logger.error("Unable to resolve " + cmd.getHypervisor() + " to a valid supported hypervisor type");
+			throw new InvalidParameterValueException("Unable to resolve " + cmd.getHypervisor() + " to a supported ");
 		}
 
 		Cluster.ClusterType clusterType = null;
@@ -625,8 +626,8 @@ public class AgentManagerImpl implements AgentManager, HandlerFactory,
 
 		Discoverer discoverer = getMatchingDiscover(hypervisorType);
 		if (discoverer == null) {
-			throw new InvalidParameterValueException(
+			
-					"Please specify a valid hypervisor");
+			throw new InvalidParameterValueException("Could not find corresponding resource manager for " + cmd.getHypervisor());
 		}
 
 		List<ClusterVO> result = new ArrayList<ClusterVO>();
@@ -664,8 +665,7 @@ public class AgentManagerImpl implements AgentManager, HandlerFactory,
 				uri = new URI(UriUtils.encodeURIComponent(url));
 				if (uri.getScheme() == null) {
 					throw new InvalidParameterValueException(
-							"uri.scheme is null " + url
+							"uri.scheme is null " + url + ", add http:// as a prefix");
-									+ ", add http:// as a prefix");
 				} else if (uri.getScheme().equalsIgnoreCase("http")) {
 					if (uri.getHost() == null
 							|| uri.getHost().equalsIgnoreCase("")

server/src/com/cloud/maid/StackMaid.java

@@ -8,7 +8,8 @@ import org.apache.log4j.Logger;
 import com.cloud.maid.dao.StackMaidDao;
 import com.cloud.maid.dao.StackMaidDaoImpl;
 import com.cloud.serializer.SerializerHelper;
-import com.cloud.utils.ActionDelegate;
+import com.cloud.utils.CleanupDelegate;
+import com.cloud.utils.db.Transaction;
 
 public class StackMaid {
     protected final static Logger s_logger = Logger.getLogger(StackMaid.class);
@@ -43,6 +44,16 @@ public class StackMaid {
 	public Object getContext(String key) {
 		return context.get(key);
 	}
+	
+	public void expungeMaidItem(long maidId) {
+		// this is a bit ugly, but when it is not loaded by component locator, this is just a workable way for now
+		Transaction txn = Transaction.open(Transaction.CLOUD_DB);
+		try {
+			maidDao.expunge(maidId);
+		} finally {
+			txn.close();
+		}
+	}
 
 	public int push(String delegateClzName, Object context) {
 		assert(msid_setby_manager != 0) : "Fatal, make sure StackMaidManager is loaded";
@@ -98,13 +109,15 @@ public class StackMaid {
 		context.clear();
 	}
 	
-	public static void doCleanup(StackMaidVO maid) {
+	public static boolean doCleanup(StackMaidVO maid) {
 		if(maid.getDelegate() != null) {
 			try {
 				Class<?> clz = Class.forName(maid.getDelegate());
 				Object delegate = clz.newInstance();
-				if(delegate instanceof ActionDelegate) {
+				if(delegate instanceof CleanupDelegate) {
-					((ActionDelegate)delegate).action(SerializerHelper.fromSerializedString(maid.getContext()));
+					return ((CleanupDelegate)delegate).cleanup(SerializerHelper.fromSerializedString(maid.getContext()), maid);
+				} else {
+					assert(false);
 				}
 			} catch (final ClassNotFoundException e) {
 				s_logger.error("Unable to load StackMaid delegate class: " + maid.getDelegate(), e);
@@ -117,6 +130,9 @@ public class StackMaid {
             } catch (final IllegalAccessException e) {
             	s_logger.error("Illegal access exception when loading resource: " + maid.getDelegate());
             } 
+            
+            return false;
 		}
+		return true;
 	}
 }

server/src/com/cloud/maid/StackMaidManagerImpl.java

@@ -51,8 +51,8 @@ public class StackMaidManagerImpl implements StackMaidManager {
 	
 	private void cleanupLeftovers(List<StackMaidVO> l) {
 		for(StackMaidVO maid : l) {
-			StackMaid.doCleanup(maid);
+			if(StackMaid.doCleanup(maid))
-			_maidDao.expunge(maid.getId());
+				_maidDao.expunge(maid.getId());
 		}
 	}
 	

server/test/com/cloud/async/CleanupDelegate.java

@@ -2,13 +2,12 @@ package com.cloud.async;
 
 import org.apache.log4j.Logger;
 
-import com.cloud.utils.ActionDelegate;
+public class CleanupDelegate implements com.cloud.utils.CleanupDelegate<String, Object> {
-
-public class CleanupDelegate implements ActionDelegate<String> {
     private static final Logger s_logger = Logger.getLogger(CleanupDelegate.class);
 
 	@Override
-	public void action(String param) {
+	public boolean cleanup(String param, Object managerContext) {
 		s_logger.info("Action called with param: " + param);
+		return true;
 	}
 }

utils/src/com/cloud/utils/CleanupDelegate.java

@@ -0,0 +1,5 @@
+package com.cloud.utils;
+
+public interface CleanupDelegate<T, M> {
+	boolean cleanup(T itemContext, M managerContext);
+}