Move MultipartMessageManager into NodeStatisticsHandler
[controller.git] / opendaylight / md-sal / statistics-manager / src / main / java / org / opendaylight / controller / md / statistics / manager / StatisticsProvider.java
index af56a84db5611974d0537d65b914df6acbf4adc0..3ee059d1c0e06f45e7c14a832e088b3dfc906029 100644 (file)
  */
 package org.opendaylight.controller.md.statistics.manager;
 
-import java.util.List;
+import java.util.Collection;
+import java.util.Timer;
+import java.util.TimerTask;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
 
-import org.eclipse.xtext.xbase.lib.Exceptions;
+import org.opendaylight.controller.md.statistics.manager.MultipartMessageManager.StatsRequestType;
 import org.opendaylight.controller.sal.binding.api.NotificationProviderService;
+import org.opendaylight.controller.sal.binding.api.RpcConsumerRegistry;
+import org.opendaylight.controller.sal.binding.api.data.DataBrokerService;
+import org.opendaylight.controller.sal.binding.api.data.DataChangeListener;
 import org.opendaylight.controller.sal.binding.api.data.DataModificationTransaction;
 import org.opendaylight.controller.sal.binding.api.data.DataProviderService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.FlowCapableNode;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.FlowCapableNodeConnector;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.meters.Meter;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.Table;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.TableKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.table.Flow;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.statistics.rev130819.GetAggregateFlowStatisticsFromFlowTableForAllFlowsInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.statistics.rev130819.GetAggregateFlowStatisticsFromFlowTableForAllFlowsOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.statistics.rev130819.GetAllFlowsStatisticsFromAllFlowTablesInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.statistics.rev130819.GetAllFlowsStatisticsFromAllFlowTablesOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.statistics.rev130819.GetFlowStatisticsFromFlowTableInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.statistics.rev130819.GetFlowStatisticsFromFlowTableOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.statistics.rev130819.OpendaylightFlowStatisticsService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.table.statistics.rev131215.GetFlowTablesStatisticsInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.table.statistics.rev131215.GetFlowTablesStatisticsOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.table.statistics.rev131215.OpendaylightFlowTableStatisticsService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.port.rev130925.queues.Queue;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.queue.rev130925.QueueId;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.group.statistics.rev131111.GetAllGroupStatisticsInputBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.group.statistics.rev131111.GetAllGroupStatisticsOutput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.group.statistics.rev131111.GetGroupDescriptionInputBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.group.statistics.rev131111.GetGroupDescriptionOutput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.group.statistics.rev131111.OpendaylightGroupStatisticsService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.group.types.rev131018.groups.Group;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeConnectorId;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeRef;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.Nodes;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.node.NodeConnector;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.meter.statistics.rev131111.GetAllMeterConfigStatisticsInputBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.meter.statistics.rev131111.GetAllMeterConfigStatisticsOutput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.meter.statistics.rev131111.GetAllMeterStatisticsInputBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.meter.statistics.rev131111.GetAllMeterStatisticsOutput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.meter.statistics.rev131111.OpendaylightMeterStatisticsService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.port.statistics.rev131214.GetAllNodeConnectorsStatisticsInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.port.statistics.rev131214.GetAllNodeConnectorsStatisticsOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.port.statistics.rev131214.OpendaylightPortStatisticsService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.queue.statistics.rev131216.GetAllQueuesStatisticsFromAllPortsInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.queue.statistics.rev131216.GetAllQueuesStatisticsFromAllPortsOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.queue.statistics.rev131216.GetQueueStatisticsFromGivenPortInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.queue.statistics.rev131216.GetQueueStatisticsFromGivenPortOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.queue.statistics.rev131216.OpendaylightQueueStatisticsService;
+import org.opendaylight.yangtools.concepts.ListenerRegistration;
 import org.opendaylight.yangtools.concepts.Registration;
+import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.opendaylight.yangtools.yang.binding.NotificationListener;
 import org.opendaylight.yangtools.yang.common.RpcResult;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.common.base.Preconditions;
+
+/**
+ * Following are main responsibilities of the class:
+ * 1) Invoke statistics request thread to send periodic statistics request to all the
+ * flow capable switch connected to the controller. It sends statistics request for
+ * Group,Meter,Table,Flow,Queue,Aggregate stats.
+ *
+ * 2) Invoke statistics ager thread, to clean up all the stale statistics data from
+ * operational data store.
+ *
+ * @author avishnoi@in.ibm.com
+ *
+ */
 public class StatisticsProvider implements AutoCloseable {
+    public static final long STATS_COLLECTION_MILLIS = TimeUnit.SECONDS.toMillis(15);
+
+    private static final Logger spLogger = LoggerFactory.getLogger(StatisticsProvider.class);
 
-    public final static Logger spLogger = LoggerFactory.getLogger(StatisticsProvider.class);
-    
-    private DataProviderService dps;
+    private final ConcurrentMap<NodeId, NodeStatisticsHandler> handlers = new ConcurrentHashMap<>();
+    private final Timer timer = new Timer("statistics-manager", true);
+    private final DataProviderService dps;
 
-    private NotificationProviderService nps;
-    
     private OpendaylightGroupStatisticsService groupStatsService;
-    
+
     private OpendaylightMeterStatisticsService meterStatsService;
-    
-    private Thread statisticsRequesterThread;
-    
-    private final  InstanceIdentifier<Nodes> nodesIdentifier = InstanceIdentifier.builder(Nodes.class).toInstance();
-    
-    private final int STATS_THREAD_EXECUTION_TIME= 50000;
-    //Local caching of stats
-    
-    private final ConcurrentMap<NodeId,NodeStatistics> statisticsCache = 
-            new ConcurrentHashMap<NodeId,NodeStatistics>();
-    
-    public DataProviderService getDataService() {
-      return this.dps;
-    }
-    
-    public void setDataService(final DataProviderService dataService) {
-      this.dps = dataService;
-    }
-    
-    public NotificationProviderService getNotificationService() {
-      return this.nps;
-    }
-    
-    public void setNotificationService(final NotificationProviderService notificationService) {
-      this.nps = notificationService;
-    }
-
-    private final StatisticsUpdateCommiter updateCommiter = new StatisticsUpdateCommiter(StatisticsProvider.this);
-    
+
+    private OpendaylightFlowStatisticsService flowStatsService;
+
+    private OpendaylightPortStatisticsService portStatsService;
+
+    private OpendaylightFlowTableStatisticsService flowTableStatsService;
+
+    private OpendaylightQueueStatisticsService queueStatsService;
+
+    private StatisticsUpdateHandler statsUpdateHandler;
+
+    public StatisticsProvider(final DataProviderService dataService) {
+        this.dps = Preconditions.checkNotNull(dataService);
+    }
+
+    private final StatisticsListener updateCommiter = new StatisticsListener(StatisticsProvider.this);
+
     private Registration<NotificationListener> listenerRegistration;
-    
-    public void start() {
-        
-        NotificationProviderService nps = this.getNotificationService();
-        Registration<NotificationListener> registerNotificationListener = nps.registerNotificationListener(this.updateCommiter);
-        this.listenerRegistration = registerNotificationListener;
-        
-        // Get Group/Meter statistics service instance
-        groupStatsService = StatisticsManagerActivator.getProviderContext().
-                getRpcService(OpendaylightGroupStatisticsService.class);
-        
-        meterStatsService = StatisticsManagerActivator.getProviderContext().
-                getRpcService(OpendaylightMeterStatisticsService.class);
-
-        statisticsRequesterThread = new Thread( new Runnable(){
 
+    private ListenerRegistration<DataChangeListener> flowCapableTrackerRegistration;
+
+    public void start(final DataBrokerService dbs, final NotificationProviderService nps, final RpcConsumerRegistry rpcRegistry) {
+
+        // Get Group/Meter statistics service instances
+        groupStatsService = rpcRegistry.getRpcService(OpendaylightGroupStatisticsService.class);
+        meterStatsService = rpcRegistry.getRpcService(OpendaylightMeterStatisticsService.class);
+        flowStatsService = rpcRegistry.getRpcService(OpendaylightFlowStatisticsService.class);
+        portStatsService = rpcRegistry.getRpcService(OpendaylightPortStatisticsService.class);
+        flowTableStatsService = rpcRegistry.getRpcService(OpendaylightFlowTableStatisticsService.class);
+        queueStatsService = rpcRegistry.getRpcService(OpendaylightQueueStatisticsService.class);
+
+        // Start receiving notifications
+        this.listenerRegistration = nps.registerNotificationListener(this.updateCommiter);
+
+        // Register for switch connect/disconnect notifications
+        final InstanceIdentifier<FlowCapableNode> fcnId = InstanceIdentifier.builder(Nodes.class)
+                .child(Node.class).augmentation(FlowCapableNode.class).build();
+        spLogger.debug("Registering FlowCapable tracker to {}", fcnId);
+        this.flowCapableTrackerRegistration = dbs.registerDataChangeListener(fcnId,
+                new FlowCapableTracker(this, fcnId));
+
+        statsUpdateHandler = new StatisticsUpdateHandler(StatisticsProvider.this);
+        registerDataStoreUpdateListener(dbs);
+
+        timer.schedule(new TimerTask() {
             @Override
             public void run() {
-                while(true){
-                    try {
-                        statsRequestSender();
-                        
-                        Thread.sleep(STATS_THREAD_EXECUTION_TIME);
-                    }catch (Exception e){
-                        spLogger.error("Exception occurred while sending stats request : {}",e);
+                try {
+                    // Send stats requests
+                    for (NodeStatisticsHandler h : handlers.values()) {
+                        sendStatisticsRequestsToNode(h);
+                    }
+
+                    // Perform cleanup
+                    for(NodeStatisticsHandler nodeStatisticsAger : handlers.values()){
+                        nodeStatisticsAger.cleanStaleStatistics();
                     }
+
+                } catch (RuntimeException e) {
+                    spLogger.warn("Failed to request statistics", e);
                 }
             }
-        });
-        
-        spLogger.debug("Statistics requester thread started with timer interval : {}",STATS_THREAD_EXECUTION_TIME);
-        
-        statisticsRequesterThread.start();
-        
+        }, 0, STATS_COLLECTION_MILLIS);
+
+        spLogger.debug("Statistics timer task with timer interval : {}ms", STATS_COLLECTION_MILLIS);
         spLogger.info("Statistics Provider started.");
     }
-    
+
+    private void registerDataStoreUpdateListener(DataBrokerService dbs) {
+        // FIXME: the below should be broken out into StatisticsUpdateHandler
+
+        //Register for flow updates
+        InstanceIdentifier<? extends DataObject> pathFlow = InstanceIdentifier.builder(Nodes.class).child(Node.class)
+                                                                    .augmentation(FlowCapableNode.class)
+                                                                    .child(Table.class)
+                                                                    .child(Flow.class).toInstance();
+        dbs.registerDataChangeListener(pathFlow, statsUpdateHandler);
+
+        //Register for meter updates
+        InstanceIdentifier<? extends DataObject> pathMeter = InstanceIdentifier.builder(Nodes.class).child(Node.class)
+                                                    .augmentation(FlowCapableNode.class)
+                                                    .child(Meter.class).toInstance();
+
+        dbs.registerDataChangeListener(pathMeter, statsUpdateHandler);
+
+        //Register for group updates
+        InstanceIdentifier<? extends DataObject> pathGroup = InstanceIdentifier.builder(Nodes.class).child(Node.class)
+                                                    .augmentation(FlowCapableNode.class)
+                                                    .child(Group.class).toInstance();
+        dbs.registerDataChangeListener(pathGroup, statsUpdateHandler);
+
+        //Register for queue updates
+        InstanceIdentifier<? extends DataObject> pathQueue = InstanceIdentifier.builder(Nodes.class).child(Node.class)
+                                                                    .child(NodeConnector.class)
+                                                                    .augmentation(FlowCapableNodeConnector.class)
+                                                                    .child(Queue.class).toInstance();
+        dbs.registerDataChangeListener(pathQueue, statsUpdateHandler);
+    }
+
     protected DataModificationTransaction startChange() {
-        
-        DataProviderService dps = this.getDataService();
         return dps.beginTransaction();
     }
-    
-    private void statsRequestSender(){
-        
-        //Need to call API to receive all the nodes connected to controller.
-        List<Node> targetNodes = getAllConnectedNodes();
-        
-        if(targetNodes == null)
-            return;
-
-        for (Node targetNode : targetNodes){
-            
-            
-            //We need to add check, so see if groups/meters are supported
-            //by the target node. Below check doesn't look good.
-            if(targetNode.getId().getValue().contains("openflow:")){
-                spLogger.info("Send request for stats collection to node : {})",targetNode.getId());
-                InstanceIdentifier<Node> targetInstanceId = InstanceIdentifier.builder(Nodes.class).child(Node.class,targetNode.getKey()).toInstance();
-                NodeRef targetNodeRef = new NodeRef(targetInstanceId);
-                
-                try{
-                  sendAllGroupStatisticsRequest(targetNodeRef);
-                  Thread.sleep(1000);
-                  sendAllMeterStatisticsRequest(targetNodeRef);
-                  Thread.sleep(1000);
-                  sendGroupDescriptionRequest(targetNodeRef);
-                  Thread.sleep(1000);
-                  sendMeterConfigStatisticsRequest(targetNodeRef);
-                  Thread.sleep(1000);
-                }catch(Exception e){
-                    spLogger.error("Exception occured while sending statistics request : {}", e);
-                }
+
+    private void sendStatisticsRequestsToNode(final NodeStatisticsHandler h) {
+        NodeKey targetNode = h.getTargetNodeKey();
+        spLogger.debug("Send requests for statistics collection to node : {}", targetNode.getId());
+
+        try{
+            if(flowTableStatsService != null){
+                sendAllFlowTablesStatisticsRequest(h);
+            }
+            if(flowStatsService != null){
+                // FIXME: it does not make sense to trigger this before sendAllFlowTablesStatisticsRequest()
+                //        comes back -- we do not have any tables anyway.
+                sendAggregateFlowsStatsFromAllTablesRequest(h);
+
+                sendAllFlowsStatsFromAllTablesRequest(h);
             }
+            if(portStatsService != null){
+                sendAllNodeConnectorsStatisticsRequest(h);
+            }
+            if(groupStatsService != null){
+                sendAllGroupStatisticsRequest(h);
+                sendGroupDescriptionRequest(h);
+            }
+            if(meterStatsService != null){
+                sendAllMeterStatisticsRequest(h);
+                sendMeterConfigStatisticsRequest(h);
+            }
+            if(queueStatsService != null){
+                sendAllQueueStatsFromAllNodeConnector(h);
+            }
+        }catch(Exception e){
+            spLogger.error("Exception occured while sending statistics requests : {}", e);
+        }
+    }
+
+
+    private void sendAllFlowTablesStatisticsRequest(NodeStatisticsHandler h) throws InterruptedException, ExecutionException {
+        final GetFlowTablesStatisticsInputBuilder input =
+                new GetFlowTablesStatisticsInputBuilder();
+
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetFlowTablesStatisticsOutput>> response =
+                flowTableStatsService.getFlowTablesStatistics(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_FLOW_TABLE);
+    }
+
+    private void sendAllFlowsStatsFromAllTablesRequest(NodeStatisticsHandler h) throws InterruptedException, ExecutionException{
+        final GetAllFlowsStatisticsFromAllFlowTablesInputBuilder input =
+                new GetAllFlowsStatisticsFromAllFlowTablesInputBuilder();
+
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetAllFlowsStatisticsFromAllFlowTablesOutput>> response =
+                flowStatsService.getAllFlowsStatisticsFromAllFlowTables(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_FLOW);
+    }
+
+    public void sendFlowStatsFromTableRequest(NodeKey node, Flow flow) throws InterruptedException, ExecutionException {
+        final NodeStatisticsHandler h = getStatisticsHandler(node.getId());
+        if (h != null) {
+            sendFlowStatsFromTableRequest(h, flow);
+        }
+    }
+
+    private void sendFlowStatsFromTableRequest(NodeStatisticsHandler h, Flow flow) throws InterruptedException, ExecutionException{
+        final GetFlowStatisticsFromFlowTableInputBuilder input =
+                new GetFlowStatisticsFromFlowTableInputBuilder(flow);
+
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetFlowStatisticsFromFlowTableOutput>> response =
+                flowStatsService.getFlowStatisticsFromFlowTable(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_FLOW);
+    }
+
+    private void sendAggregateFlowsStatsFromAllTablesRequest(final NodeStatisticsHandler h) throws InterruptedException, ExecutionException{
+        final Collection<TableKey> tables = h.getKnownTables();
+        spLogger.debug("Node {} supports {} table(s)", h, tables.size());
+
+        for (TableKey key : h.getKnownTables()) {
+            sendAggregateFlowsStatsFromTableRequest(h, key.getId().shortValue());
         }
     }
-    
-    private void sendAllGroupStatisticsRequest(NodeRef targetNode){
-        
+
+    private void sendAggregateFlowsStatsFromTableRequest(final NodeStatisticsHandler h, Short tableId) throws InterruptedException, ExecutionException{
+
+        spLogger.debug("Send aggregate stats request for flow table {} to node {}",tableId, h.getTargetNodeKey());
+        GetAggregateFlowStatisticsFromFlowTableForAllFlowsInputBuilder input =
+                new GetAggregateFlowStatisticsFromFlowTableForAllFlowsInputBuilder();
+
+        input.setNode(new NodeRef(InstanceIdentifier.builder(Nodes.class).child(Node.class, h.getTargetNodeKey()).toInstance()));
+        input.setTableId(new org.opendaylight.yang.gen.v1.urn.opendaylight.table.types.rev131026.TableId(tableId));
+        Future<RpcResult<GetAggregateFlowStatisticsFromFlowTableForAllFlowsOutput>> response =
+                flowStatsService.getAggregateFlowStatisticsFromFlowTableForAllFlows(input.build());
+
+        h.recordExpectedTableTransaction(response.get().getResult().getTransactionId(), tableId);
+    }
+
+    private void sendAllNodeConnectorsStatisticsRequest(NodeStatisticsHandler h) throws InterruptedException, ExecutionException{
+
+        final GetAllNodeConnectorsStatisticsInputBuilder input = new GetAllNodeConnectorsStatisticsInputBuilder();
+
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetAllNodeConnectorsStatisticsOutput>> response =
+                portStatsService.getAllNodeConnectorsStatistics(input.build());
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_PORT);
+    }
+
+    private void sendAllGroupStatisticsRequest(NodeStatisticsHandler h) throws InterruptedException, ExecutionException{
+
         final GetAllGroupStatisticsInputBuilder input = new GetAllGroupStatisticsInputBuilder();
-        
-        input.setNode(targetNode);
-        input.setNode(targetNode);
 
-        @SuppressWarnings("unused")
-        Future<RpcResult<GetAllGroupStatisticsOutput>> response = 
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetAllGroupStatisticsOutput>> response =
                 groupStatsService.getAllGroupStatistics(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_GROUP);
+    }
+
+    public void sendGroupDescriptionRequest(NodeKey node) throws InterruptedException, ExecutionException{
+        final NodeStatisticsHandler h = getStatisticsHandler(node.getId());
+        if (h != null) {
+            sendGroupDescriptionRequest(h);
+        }
     }
-    
-    private void sendGroupDescriptionRequest(NodeRef targetNode){
+
+    private void sendGroupDescriptionRequest(NodeStatisticsHandler h) throws InterruptedException, ExecutionException{
         final GetGroupDescriptionInputBuilder input = new GetGroupDescriptionInputBuilder();
-        
-        input.setNode(targetNode);
 
-        @SuppressWarnings("unused")
-        Future<RpcResult<GetGroupDescriptionOutput>> response = 
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetGroupDescriptionOutput>> response =
                 groupStatsService.getGroupDescription(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.GROUP_DESC);
     }
-    
-    private void sendAllMeterStatisticsRequest(NodeRef targetNode){
-        
+
+    private void sendAllMeterStatisticsRequest(NodeStatisticsHandler h) throws InterruptedException, ExecutionException{
+
         GetAllMeterStatisticsInputBuilder input = new GetAllMeterStatisticsInputBuilder();
-        
-        input.setNode(targetNode);
 
-        @SuppressWarnings("unused")
-        Future<RpcResult<GetAllMeterStatisticsOutput>> response = 
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetAllMeterStatisticsOutput>> response =
                 meterStatsService.getAllMeterStatistics(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_METER);
+    }
+
+    public void sendMeterConfigStatisticsRequest(NodeKey node) throws InterruptedException, ExecutionException {
+        final NodeStatisticsHandler h = getStatisticsHandler(node.getId());
+        if (h != null) {
+            sendMeterConfigStatisticsRequest(h);
+        }
     }
-    
-    private void sendMeterConfigStatisticsRequest(NodeRef targetNode){
-        
+
+    private void sendMeterConfigStatisticsRequest(NodeStatisticsHandler h) throws InterruptedException, ExecutionException{
+
         GetAllMeterConfigStatisticsInputBuilder input = new GetAllMeterConfigStatisticsInputBuilder();
-        
-        input.setNode(targetNode);
 
-        @SuppressWarnings("unused")
-        Future<RpcResult<GetAllMeterConfigStatisticsOutput>> response = 
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetAllMeterConfigStatisticsOutput>> response =
                 meterStatsService.getAllMeterConfigStatistics(input.build());
-        
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.METER_CONFIG);;
+    }
+
+    private void sendAllQueueStatsFromAllNodeConnector(NodeStatisticsHandler h) throws InterruptedException, ExecutionException {
+        GetAllQueuesStatisticsFromAllPortsInputBuilder input = new GetAllQueuesStatisticsFromAllPortsInputBuilder();
+
+        input.setNode(h.getTargetNodeRef());
+
+        Future<RpcResult<GetAllQueuesStatisticsFromAllPortsOutput>> response =
+                queueStatsService.getAllQueuesStatisticsFromAllPorts(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_QUEUE_STATS);;
     }
-    
-    public ConcurrentMap<NodeId, NodeStatistics> getStatisticsCache() {
-        return statisticsCache;
+
+    public void sendQueueStatsFromGivenNodeConnector(NodeKey node,NodeConnectorId nodeConnectorId, QueueId queueId) throws InterruptedException, ExecutionException {
+        final NodeStatisticsHandler h = getStatisticsHandler(node.getId());
+        if (h != null) {
+            sendQueueStatsFromGivenNodeConnector(h, nodeConnectorId, queueId);
+        }
     }
-    
-    private List<Node> getAllConnectedNodes(){
-        
-        Nodes nodes = (Nodes) dps.readOperationalData(nodesIdentifier);
-        if(nodes == null)
-            return null;
-        
-        spLogger.info("Number of connected nodes : {}",nodes.getNode().size());
-        return nodes.getNode();
+
+    private void sendQueueStatsFromGivenNodeConnector(NodeStatisticsHandler h, NodeConnectorId nodeConnectorId, QueueId queueId) throws InterruptedException, ExecutionException {
+        GetQueueStatisticsFromGivenPortInputBuilder input = new GetQueueStatisticsFromGivenPortInputBuilder();
+
+        input.setNode(h.getTargetNodeRef());
+        input.setNodeConnectorId(nodeConnectorId);
+        input.setQueueId(queueId);
+        Future<RpcResult<GetQueueStatisticsFromGivenPortOutput>> response =
+                queueStatsService.getQueueStatisticsFromGivenPort(input.build());
+
+        h.recordExpectedTransaction(response.get().getResult().getTransactionId(), StatsRequestType.ALL_QUEUE_STATS);;
+    }
+
+    /**
+     * Get the handler for a particular node.
+     *
+     * @param nodeId source node
+     * @return Node statistics handler for that node. Null if the statistics should
+     *         not handled.
+     */
+    public final NodeStatisticsHandler getStatisticsHandler(final NodeId nodeId) {
+        Preconditions.checkNotNull(nodeId);
+        NodeStatisticsHandler handler = handlers.get(nodeId);
+        if (handler == null) {
+            spLogger.info("Attempted to get non-existing handler for {}", nodeId);
+        }
+        return handler;
     }
 
-    @SuppressWarnings("deprecation")
     @Override
-    public void close(){
-        
+    public void close() {
         try {
-            spLogger.info("Statistics Provider stopped.");
             if (this.listenerRegistration != null) {
-              
                 this.listenerRegistration.close();
-                
-                this.statisticsRequesterThread.destroy();
-            
+                this.listenerRegistration = null;
             }
-          } catch (Throwable e) {
-            throw Exceptions.sneakyThrow(e);
-          }
+            if (this.flowCapableTrackerRegistration != null) {
+                this.flowCapableTrackerRegistration.close();
+                this.flowCapableTrackerRegistration = null;
+            }
+            timer.cancel();
+        } catch (Exception e) {
+            spLogger.warn("Failed to stop Statistics Provider completely", e);
+        } finally {
+            spLogger.info("Statistics Provider stopped.");
+        }
     }
 
+    void startNodeHandlers(final Collection<NodeKey> addedNodes) {
+        for (NodeKey key : addedNodes) {
+            if (handlers.containsKey(key.getId())) {
+                spLogger.warn("Attempted to start already-existing handler for {}, very strange", key.getId());
+                continue;
+            }
+
+            final NodeStatisticsHandler h = new NodeStatisticsHandler(dps, key);
+            final NodeStatisticsHandler old = handlers.putIfAbsent(key.getId(), h);
+            if (old == null) {
+                spLogger.debug("Started node handler for {}", key.getId());
+
+                // FIXME: this should be in the NodeStatisticsHandler itself
+                sendStatisticsRequestsToNode(h);
+            } else {
+                spLogger.debug("Prevented race on handler for {}", key.getId());
+            }
+        }
+    }
+
+    void stopNodeHandlers(final Collection<NodeKey> removedNodes) {
+        for (NodeKey key : removedNodes) {
+            final NodeStatisticsHandler s = handlers.remove(key.getId());
+            if (s != null) {
+                spLogger.debug("Stopping node handler for {}", key.getId());
+                s.close();
+            } else {
+                spLogger.warn("Attempted to remove non-existing handler for {}, very strange", key.getId());
+            }
+        }
+    }
 }