More detailed subscriber event logging
[lispflowmapping.git] / mappingservice / implementation / src / main / java / org / opendaylight / lispflowmapping / implementation / lisp / MapServer.java
index 313d7a89b6070919ad9edbdde8de79270298ecce..ed5427d7c05664ba61c390ccd77a7bfaccc3825c 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Contextream, Inc. and others.  All rights reserved.
+ * Copyright (c) 2014, 2017 Contextream, Inc. and others.  All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
@@ -8,79 +8,92 @@
 
 package org.opendaylight.lispflowmapping.implementation.lisp;
 
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Maps;
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import java.net.InetAddress;
 import java.net.NetworkInterface;
 import java.net.SocketException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
-
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
 import org.apache.commons.lang3.BooleanUtils;
-import org.apache.commons.lang3.exception.ExceptionUtils;
 import org.opendaylight.controller.md.sal.binding.api.NotificationService;
-import org.opendaylight.lispflowmapping.implementation.authentication.LispAuthenticationUtil;
-import org.opendaylight.lispflowmapping.implementation.config.ConfigIni;
+import org.opendaylight.lispflowmapping.config.ConfigIni;
+import org.opendaylight.lispflowmapping.implementation.util.LoggingUtil;
+import org.opendaylight.lispflowmapping.implementation.util.MSNotificationInputUtil;
 import org.opendaylight.lispflowmapping.interfaces.dao.SubKeys;
-import org.opendaylight.lispflowmapping.interfaces.dao.SubscriberRLOC;
+import org.opendaylight.lispflowmapping.interfaces.dao.Subscriber;
 import org.opendaylight.lispflowmapping.interfaces.lisp.IMapNotifyHandler;
 import org.opendaylight.lispflowmapping.interfaces.lisp.IMapServerAsync;
+import org.opendaylight.lispflowmapping.interfaces.lisp.ISmrNotificationListener;
+import org.opendaylight.lispflowmapping.interfaces.lisp.SmrEvent;
 import org.opendaylight.lispflowmapping.interfaces.mappingservice.IMappingService;
+import org.opendaylight.lispflowmapping.lisp.authentication.LispAuthenticationUtil;
 import org.opendaylight.lispflowmapping.lisp.type.LispMessage;
+import org.opendaylight.lispflowmapping.lisp.type.MappingData;
 import org.opendaylight.lispflowmapping.lisp.util.LispAddressStringifier;
 import org.opendaylight.lispflowmapping.lisp.util.LispAddressUtil;
 import org.opendaylight.lispflowmapping.lisp.util.MapNotifyBuilderHelper;
 import org.opendaylight.lispflowmapping.lisp.util.MapRequestUtil;
+import org.opendaylight.lispflowmapping.lisp.util.MappingRecordUtil;
 import org.opendaylight.lispflowmapping.lisp.util.SourceDestKeyHelper;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.IpAddress;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.PortNumber;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.PortNumber;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.lisp.address.types.rev151105.lisp.address.address.SourceDestKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.inet.binary.types.rev160303.IpAddressBinary;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.MapRegister;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.SiteId;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.eid.container.Eid;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.eid.list.EidItem;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.eid.list.EidItemBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapnotifymessage.MapNotifyBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping.authkey.container.MappingAuthkey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping.record.container.MappingRecord;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping.record.container.MappingRecordBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping.record.list.MappingRecordItem;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping.record.list.MappingRecordItemBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.maprequestnotification.MapRequestBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.transport.address.TransportAddress;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.transport.address.TransportAddressBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.MappingChange;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.MappingChanged;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.MappingOrigin;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.OdlMappingserviceListener;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.mapping.authkey.container.MappingAuthkey;
+import org.opendaylight.yangtools.concepts.ListenerRegistration;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.common.base.Preconditions;
-
-public class MapServer implements IMapServerAsync, OdlMappingserviceListener {
+public class MapServer implements IMapServerAsync, OdlMappingserviceListener, ISmrNotificationListener {
 
     protected static final Logger LOG = LoggerFactory.getLogger(MapServer.class);
+    private static final byte[] ALL_ZEROES_XTR_ID = new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ,0};
     private IMappingService mapService;
-    private boolean authenticate;
     private boolean subscriptionService;
     private IMapNotifyHandler notifyHandler;
     private NotificationService notificationService;
+    private ListenerRegistration<MapServer> mapServerListenerRegistration;
+    private SmrScheduler scheduler;
 
-    public MapServer(IMappingService mapService, boolean authenticate, boolean subscriptionService,
-            IMapNotifyHandler notifyHandler, NotificationService notificationService) {
+    public MapServer(IMappingService mapService, boolean subscriptionService,
+                     IMapNotifyHandler notifyHandler, NotificationService notificationService) {
         Preconditions.checkNotNull(mapService);
         this.mapService = mapService;
-        this.authenticate = authenticate;
         this.subscriptionService = subscriptionService;
         this.notifyHandler = notifyHandler;
         this.notificationService = notificationService;
         if (notificationService != null) {
             notificationService.registerNotificationListener(this);
         }
+        scheduler = new SmrScheduler();
     }
 
     @Override
@@ -88,66 +101,75 @@ public class MapServer implements IMapServerAsync, OdlMappingserviceListener {
         this.subscriptionService = subscriptionService;
     }
 
-    @Override
-    public boolean shouldAuthenticate() {
-        return authenticate;
-    }
-
-    @Override
-    public void setShouldAuthenticate(boolean shouldAuthenticate) {
-        authenticate = shouldAuthenticate;
-    }
-
     @SuppressWarnings("unchecked")
     public void handleMapRegister(MapRegister mapRegister) {
-        boolean authFailed = false;
         boolean mappingUpdated = false;
-        MappingAuthkey authkey = null;
-        Set<SubscriberRLOC> subscribers = null;
+        boolean oldMappingRemoved = false;
+        boolean merge = ConfigIni.getInstance().mappingMergeIsSet() && mapRegister.isMergeEnabled();
+        Set<Subscriber> subscribers = null;
         MappingRecord oldMapping;
 
+        if (merge) {
+            if (!mapRegister.isXtrSiteIdPresent() || mapRegister.getXtrId() == null) {
+                LOG.error("Merge bit is set in Map-Register, but xTR-ID is not present. Will not merge.");
+                merge = false;
+            } else if (Arrays.equals(mapRegister.getXtrId().getValue(), ALL_ZEROES_XTR_ID)) {
+                LOG.warn("Merge bit is set in Map-Register, but xTR-ID is all zeroes.");
+            }
+        }
+
         for (MappingRecordItem record : mapRegister.getMappingRecordItem()) {
             MappingRecord mapping = record.getMappingRecord();
-            if (authenticate) {
-                authkey = mapService.getAuthenticationKey(mapping.getEid());
-                if (!LispAuthenticationUtil.validate(mapRegister, mapping.getEid(), authkey)) {
-                    authFailed = true;
-                    break;
-                }
-            }
+            Eid eid = mapping.getEid();
+            MappingData mappingData = new MappingData(mapping, System.currentTimeMillis());
+            mappingData.setMergeEnabled(merge);
+            mappingData.setXtrId(mapRegister.getXtrId());
 
-            oldMapping = (MappingRecord) mapService.getMapping(MappingOrigin.Southbound, mapping.getEid());
-            mapService.addMapping(MappingOrigin.Southbound, mapping.getEid(), getSiteId(mapRegister), mapping);
+            oldMapping = getMappingRecord(mapService.getMapping(MappingOrigin.Southbound, eid));
+            mapService.addMapping(MappingOrigin.Southbound, eid, getSiteId(mapRegister), mappingData);
+            if (oldMapping != null && MappingRecordUtil.isNegativeMapping(oldMapping)) {
+                mapService.removeMapping(MappingOrigin.Southbound, oldMapping.getEid());
+                oldMappingRemoved = true;
+            }
 
             if (subscriptionService) {
-                MappingRecord newMapping = ConfigIni.getInstance().mappingMergeIsSet() ?
-                        (MappingRecord) mapService.getMapping(MappingOrigin.Southbound, mapping.getEid()) : mapping;
+                MappingRecord newMapping = merge
+                        ? getMappingRecord(mapService.getMapping(MappingOrigin.Southbound, eid)) : mapping;
 
                 if (mappingChanged(oldMapping, newMapping)) {
                     if (LOG.isDebugEnabled()) {
                         LOG.debug("Mapping update occured for {} SMRs will be sent for its subscribers.",
                                 LispAddressStringifier.getString(mapping.getEid()));
                     }
-                    subscribers = getSubscribers(mapping.getEid());
-                    sendSmrs(mapping, subscribers);
+                    subscribers = getSubscribers(eid);
+                    if (oldMapping != null && !oldMapping.getEid().equals(eid)) {
+                        subscribers = addParentSubscribers(eid, subscribers);
+                    }
+                    LoggingUtil.logSubscribers(LOG, eid, subscribers);
+                    handleSmr(eid, subscribers);
+                    if (oldMapping != null && oldMappingRemoved && !oldMapping.getEid().equals(eid)) {
+                        subscribers = getSubscribers(oldMapping.getEid());
+                        LoggingUtil.logSubscribers(LOG, oldMapping.getEid(), subscribers);
+                        handleSmr(oldMapping.getEid(), subscribers);
+                    }
                     mappingUpdated = true;
                 }
             }
         }
-        if (!authFailed && BooleanUtils.isTrue(mapRegister.isWantMapNotify())) {
+        if (BooleanUtils.isTrue(mapRegister.isWantMapNotify())) {
             LOG.trace("MapRegister wants MapNotify");
             MapNotifyBuilder builder = new MapNotifyBuilder();
             List<TransportAddress> rlocs = null;
-            if (ConfigIni.getInstance().mappingMergeIsSet()) {
-                Set<IpAddress> notifyRlocs = new HashSet<IpAddress>();
+            if (merge) {
+                Set<IpAddressBinary> notifyRlocs = new HashSet<IpAddressBinary>();
                 List<MappingRecordItem> mergedMappings = new ArrayList<MappingRecordItem>();
                 for (MappingRecordItem record : mapRegister.getMappingRecordItem()) {
                     MappingRecord mapping = record.getMappingRecord();
-                    MappingRecord currentRecord = (MappingRecord) mapService.getMapping(MappingOrigin.Southbound,
-                            mapping.getEid());
+                    MappingRecord currentRecord = getMappingRecord(mapService.getMapping(MappingOrigin.Southbound,
+                            mapping.getEid()));
                     mergedMappings.add(new MappingRecordItemBuilder().setMappingRecord(currentRecord).build());
-                    Set<IpAddress> sourceRlocs = (Set<IpAddress>) mapService.getData(MappingOrigin.Southbound,
-                            mapping.getEid(), SubKeys.SRC_RLOCS);
+                    Set<IpAddressBinary> sourceRlocs = (Set<IpAddressBinary>) mapService.getData(
+                            MappingOrigin.Southbound, mapping.getEid(), SubKeys.SRC_RLOCS);
                     if (sourceRlocs != null) {
                         notifyRlocs.addAll(sourceRlocs);
                     }
@@ -160,17 +182,22 @@ public class MapServer implements IMapServerAsync, OdlMappingserviceListener {
             } else {
                 MapNotifyBuilderHelper.setFromMapRegister(builder, mapRegister);
             }
-            if (authenticate) {
-                builder.setAuthenticationData(LispAuthenticationUtil.createAuthenticationData(builder.build(),
-                        authkey.getKeyString()));
+            List<MappingRecordItem> mappings = builder.getMappingRecordItem();
+            if (mappings != null && mappings.get(0) != null && mappings.get(0).getMappingRecord() != null
+                    && mappings.get(0).getMappingRecord().getEid() != null) {
+                MappingAuthkey authkey = mapService.getAuthenticationKey(mappings.get(0).getMappingRecord().getEid());
+                if (authkey != null) {
+                    builder.setAuthenticationData(LispAuthenticationUtil.createAuthenticationData(builder.build(),
+                            authkey.getKeyString()));
+                }
             }
             notifyHandler.handleMapNotify(builder.build(), rlocs);
         }
     }
 
-    private static List<TransportAddress> getTransportAddresses(Set<IpAddress> addresses) {
+    private static List<TransportAddress> getTransportAddresses(Set<IpAddressBinary> addresses) {
         List<TransportAddress> rlocs = new ArrayList<TransportAddress>();
-        for (IpAddress address : addresses) {
+        for (IpAddressBinary address : addresses) {
             TransportAddressBuilder tab = new TransportAddressBuilder();
             tab.setIpAddress(address);
             tab.setPort(new PortNumber(LispMessage.PORT_NUM));
@@ -179,23 +206,36 @@ public class MapServer implements IMapServerAsync, OdlMappingserviceListener {
         return rlocs;
     }
 
-    private SiteId getSiteId(MapRegister mapRegister) {
+    private static SiteId getSiteId(MapRegister mapRegister) {
         return (mapRegister.getSiteId() != null) ? new SiteId(mapRegister.getSiteId()) : null;
     }
 
+    private static MappingRecord getMappingRecord(MappingData mappingData) {
+        return (mappingData != null) ? mappingData.getRecord() : null;
+    }
+
     @Override
     public void onMappingChanged(MappingChanged notification) {
+        LOG.trace("MappingChanged event of type: `{}'", notification.getChangeType());
         if (subscriptionService) {
-            sendSmrs(notification.getMappingRecord(), getSubscribers(notification.getMappingRecord().getEid()));
-            if (notification.getChangeType().equals(MappingChange.Removed)) {
-                removeSubscribers(notification.getMappingRecord().getEid());
+            Eid eid = notification.getMappingRecord().getEid();
+            Set<Subscriber> subscribers = MSNotificationInputUtil.toSubscriberSet(notification.getSubscriberItem());
+            LoggingUtil.logSubscribers(LOG, eid, subscribers);
+            if (mapService.isMaster()) {
+                sendSmrs(eid, subscribers);
+                if (eid.getAddress() instanceof SourceDestKey) {
+                    Set<Subscriber> dstSubscribers = MSNotificationInputUtil.toSubscriberSetFromDst(
+                            notification.getDstSubscriberItem());
+                    LoggingUtil.logSubscribers(LOG, SourceDestKeyHelper.getDstBinary(eid), dstSubscribers);
+                    sendSmrs(SourceDestKeyHelper.getDstBinary(eid), dstSubscribers);
+                }
             }
         }
     }
 
     private static boolean mappingChanged(MappingRecord oldMapping, MappingRecord newMapping) {
         // We only check for fields we care about
-        // XXX: This code needs to be checked and updated when the YANG model is modified
+        // XXX: This code needs to be checked and updated when the YANG model for MappingRecord is modified
         Preconditions.checkNotNull(newMapping, "The new mapping should never be null");
         if (oldMapping == null) {
             LOG.trace("mappingChanged(): old mapping is null");
@@ -219,58 +259,50 @@ public class MapServer implements IMapServerAsync, OdlMappingserviceListener {
         return false;
     }
 
-    private void sendSmrs(MappingRecord record, Set<SubscriberRLOC> subscribers) {
-        Eid eid = record.getEid();
-        handleSmr(eid, subscribers, notifyHandler);
+    private void handleSmr(Eid eid, Set<Subscriber> subscribers) {
+        sendSmrs(eid, subscribers);
 
         // For SrcDst LCAF also send SMRs to Dst prefix
         if (eid.getAddress() instanceof SourceDestKey) {
-            Eid dstAddr = SourceDestKeyHelper.getDst(eid);
-            Set<SubscriberRLOC> dstSubs = getSubscribers(dstAddr);
-            MappingRecord newRecord = new MappingRecordBuilder(record).setEid(dstAddr).build();
-            handleSmr(newRecord.getEid(), dstSubs, notifyHandler);
+            Eid dstAddr = SourceDestKeyHelper.getDstBinary(eid);
+            Set<Subscriber> dstSubs = getSubscribers(dstAddr);
+            sendSmrs(dstAddr, dstSubs);
         }
     }
 
-    private void handleSmr(Eid eid, Set<SubscriberRLOC> subscribers, IMapNotifyHandler callback) {
+    private void sendSmrs(Eid eid, Set<Subscriber> subscribers) {
         if (subscribers == null) {
             return;
         }
-        MapRequestBuilder mrb = MapRequestUtil.prepareSMR(eid, LispAddressUtil.toRloc(getLocalAddress()));
+        final MapRequestBuilder mrb = MapRequestUtil.prepareSMR(eid, LispAddressUtil.toRloc(getLocalAddress()));
         LOG.trace("Built SMR packet: " + mrb.build().toString());
-        // Using Iterator ensures that we don't get a ConcurrentModificationException when removing a SubscriberRLOC
-        // from a Set.
-        Iterator<SubscriberRLOC> iterator = subscribers.iterator();
-        while (iterator.hasNext()) {
-            SubscriberRLOC subscriber = iterator.next();
-            if (subscriber.timedOut()) {
-                LOG.trace("Lazy removing expired subscriber entry " + subscriber.toString());
-                iterator.remove();
-            } else {
-                try {
-                    // The address stored in the SMR's EID record is used as Source EID in the SMR-invoked Map-Request.
-                    // To ensure consistent behavior it is set to the value used to originally request a given mapping
-                    mrb.setEidItem(new ArrayList<EidItem>());
-                    mrb.getEidItem().add(new EidItemBuilder().setEid(subscriber.getSrcEid()).build());
-                    callback.handleSMR(mrb.build(), subscriber.getSrcRloc());
-                } catch (Exception e) {
-                    LOG.error("Errors encountered while handling SMR:" + ExceptionUtils.getStackTrace(e));
-                }
-            }
-        }
-        addSubscribers(eid, subscribers);
+
+        scheduler.scheduleSmrs(mrb, subscribers.iterator());
     }
 
     @SuppressWarnings("unchecked")
-    private Set<SubscriberRLOC> getSubscribers(Eid address) {
-        return (Set<SubscriberRLOC>) mapService.getData(MappingOrigin.Southbound, address, SubKeys.SUBSCRIBERS);
+    private Set<Subscriber> getSubscribers(Eid address) {
+        return (Set<Subscriber>) mapService.getData(MappingOrigin.Southbound, address, SubKeys.SUBSCRIBERS);
     }
 
-    private void removeSubscribers(Eid address) {
-        mapService.removeData(MappingOrigin.Southbound, address, SubKeys.SUBSCRIBERS);
+    private Set<Subscriber> addParentSubscribers(Eid eid, Set<Subscriber> subscribers) {
+        Eid parentPrefix = mapService.getParentPrefix(eid);
+        if (parentPrefix == null) {
+            return subscribers;
+        }
+
+        Set<Subscriber> parentSubscribers = getSubscribers(parentPrefix);
+        if (parentSubscribers != null) {
+            if (subscribers != null) {
+                subscribers.addAll(parentSubscribers);
+            } else {
+                subscribers = parentSubscribers;
+            }
+        }
+        return subscribers;
     }
 
-    private void addSubscribers(Eid address, Set<SubscriberRLOC> subscribers) {
+    private void addSubscribers(Eid address, Set<Subscriber> subscribers) {
         mapService.addData(MappingOrigin.Southbound, address, SubKeys.SUBSCRIBERS, subscribers);
     }
 
@@ -279,24 +311,154 @@ public class MapServer implements IMapServerAsync, OdlMappingserviceListener {
             Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
             while (interfaces.hasMoreElements()) {
                 NetworkInterface current = interfaces.nextElement();
-                LOG.debug("Interface " + current.toString());
+                LOG.trace("Interface " + current.toString());
                 if (!current.isUp() || current.isLoopback() || current.isVirtual()) {
                     continue;
                 }
                 Enumeration<InetAddress> addresses = current.getInetAddresses();
                 while (addresses.hasMoreElements()) {
-                    InetAddress current_addr = addresses.nextElement();
+                    InetAddress currentAddr = addresses.nextElement();
                     // Skip loopback and link local addresses
-                    if (current_addr.isLoopbackAddress() || current_addr.isLinkLocalAddress()) {
+                    if (currentAddr.isLoopbackAddress() || currentAddr.isLinkLocalAddress()) {
                         continue;
                     }
-                    LOG.debug(current_addr.getHostAddress());
-                    return current_addr;
+                    LOG.debug(currentAddr.getHostAddress());
+                    return currentAddr;
                 }
             }
         } catch (SocketException se) {
-            LOG.debug("Caught socket exceptio", se);
+            LOG.debug("Caught socket exception", se);
         }
         return null;
     }
+
+    @Override
+    public void onSmrInvokedReceived(SmrEvent event) {
+        scheduler.smrReceived(event);
+    }
+
+    /**
+     * Task scheduler is responsible for resending SMR messages to a subscriber (xTR)
+     * {@value ConfigIni#LISP_SMR_RETRY_COUNT} times, or until {@link ISmrNotificationListener#onSmrInvokedReceived}
+     * is triggered.
+     */
+    private class SmrScheduler {
+        final int cpuCores = Runtime.getRuntime().availableProcessors();
+        private final ThreadFactory threadFactory = new ThreadFactoryBuilder()
+                .setNameFormat("smr-executor-%d").build();
+        private final ScheduledExecutorService executor = Executors.newScheduledThreadPool(cpuCores * 2, threadFactory);
+        private final Map<IpAddressBinary, Map<Eid, ScheduledFuture<?>>> subscriberFutureMap = Maps.newConcurrentMap();
+
+        void scheduleSmrs(MapRequestBuilder mrb, Iterator<Subscriber> subscribers) {
+            // Using Iterator ensures that we don't get a ConcurrentModificationException when removing a Subscriber
+            // from a Set.
+            while (subscribers.hasNext()) {
+                Subscriber subscriber = subscribers.next();
+                if (subscriber.timedOut()) {
+                    LOG.debug("Lazy removing expired subscriber entry " + subscriber.getString());
+                    subscribers.remove();
+                } else {
+                    final Eid srcEid = mrb.getSourceEid().getEid();
+                    final ScheduledFuture<?> future = executor.scheduleAtFixedRate(new CancellableRunnable(
+                            mrb, subscriber), 0L, ConfigIni.getInstance().getSmrTimeout(), TimeUnit.MILLISECONDS);
+                    final IpAddressBinary subscriberAddress = LispAddressUtil
+                            .addressBinaryFromAddress(subscriber.getSrcRloc().getAddress());
+
+                    if (subscriberFutureMap.containsKey(subscriberAddress)) {
+                        subscriberFutureMap.get(subscriberAddress).put(srcEid, future);
+                    } else {
+                        final Map<Eid, ScheduledFuture<?>> eidFutureMap = Maps.newConcurrentMap();
+                        eidFutureMap.put(srcEid, future);
+                        subscriberFutureMap.put(subscriberAddress, eidFutureMap);
+                    }
+                }
+            }
+        }
+
+        void smrReceived(SmrEvent event) {
+            final List<IpAddressBinary> subscriberAddressList = event.getSubscriberAddressList();
+            for (IpAddressBinary subscriberAddress : subscriberAddressList) {
+                final Map<Eid, ScheduledFuture<?>> eidFutureMap = subscriberFutureMap.get(subscriberAddress);
+                if (eidFutureMap != null) {
+                    final ScheduledFuture<?> future = eidFutureMap.get(event.getEid());
+                    if (future != null && !future.isCancelled()) {
+                        future.cancel(true);
+                        LOG.debug("SMR-invoked MapRequest received, scheduled task for subscriber {}, EID {} with"
+                                + " nonce {} has been cancelled", subscriberAddress.toString(),
+                                LispAddressStringifier.getString(event.getEid()), event.getNonce());
+                        eidFutureMap.remove(event.getEid());
+                    }
+                    if (eidFutureMap.isEmpty()) {
+                        subscriberFutureMap.remove(subscriberAddress);
+                    }
+                }
+            }
+        }
+
+        private final class CancellableRunnable implements Runnable {
+            private MapRequestBuilder mrb;
+            private Subscriber subscriber;
+            private int executionCount = 1;
+
+            CancellableRunnable(MapRequestBuilder mrb, Subscriber subscriber) {
+                this.mrb = mrb;
+                this.subscriber = subscriber;
+            }
+
+            @SuppressWarnings("checkstyle:IllegalCatch")
+            @Override
+            public void run() {
+                final IpAddressBinary subscriberAddress = LispAddressUtil
+                        .addressBinaryFromAddress(subscriber.getSrcRloc().getAddress());
+                final Eid srcEid = mrb.getSourceEid().getEid();
+
+                try {
+                    // The address stored in the SMR's EID record is used as Source EID in the SMR-invoked
+                    // Map-Request. To ensure consistent behavior it is set to the value used to originally request
+                    // a given mapping.
+                    if (executionCount <= ConfigIni.getInstance().getSmrRetryCount()) {
+                        synchronized (mrb) {
+                            mrb.setEidItem(new ArrayList<EidItem>());
+                            mrb.getEidItem().add(new EidItemBuilder().setEid(subscriber.getSrcEid()).build());
+                            notifyHandler.handleSMR(mrb.build(), subscriber.getSrcRloc());
+                            if (LOG.isTraceEnabled()) {
+                                LOG.trace("Attempt #{} to send SMR for EID {} to subscriber {}, source EID {}",
+                                        executionCount,
+                                        LispAddressStringifier.getString(mrb.getSourceEid().getEid()),
+                                        LispAddressStringifier.getString(subscriber.getSrcRloc()),
+                                        LispAddressStringifier.getString(mrb.getEidItem().get(0).getEid()));
+                            }
+                        }
+                    } else {
+                        LOG.trace("Cancelling execution of a SMR Map-Request after {} failed attempts.",
+                                executionCount - 1);
+                        cancelAndRemove(subscriberAddress, srcEid);
+                        return;
+                    }
+                } catch (Exception e) {
+                    LOG.error("Errors encountered while handling SMR:", e);
+                    cancelAndRemove(subscriberAddress, srcEid);
+                    return;
+                }
+                executionCount++;
+            }
+
+            private void cancelAndRemove(IpAddressBinary subscriberAddress, Eid eid) {
+                final Map<Eid, ScheduledFuture<?>> eidFutureMap = subscriberFutureMap.get(subscriberAddress);
+                if (eidFutureMap == null) {
+                    LOG.warn("Couldn't find subscriber {} in SMR scheduler internal list", subscriberAddress);
+                    return;
+                }
+
+                if (eidFutureMap.containsKey(eid)) {
+                    ScheduledFuture<?> eidFuture = eidFutureMap.get(eid);
+                    eidFutureMap.remove(eid);
+                    eidFuture.cancel(false);
+                }
+                if (eidFutureMap.isEmpty()) {
+                    subscriberFutureMap.remove(subscriberAddress);
+                }
+            }
+        }
+    }
 }