mappingservice/implementation/src/main/java/org/opendaylight/lispflowmapping/implementation/lisp/MapServer.java

   1 /*
   2  * Copyright (c) 2014, 2017 Contextream, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.lispflowmapping.implementation.lisp;
  10
  11 import static java.util.Objects.requireNonNull;
  12
  13 import com.google.common.util.concurrent.ThreadFactoryBuilder;
  14 import java.net.InetAddress;
  15 import java.net.NetworkInterface;
  16 import java.net.SocketException;
  17 import java.util.ArrayList;
  18 import java.util.Arrays;
  19 import java.util.Enumeration;
  20 import java.util.Iterator;
  21 import java.util.LinkedHashSet;
  22 import java.util.List;
  23 import java.util.Map;
  24 import java.util.Set;
  25 import java.util.concurrent.ConcurrentHashMap;
  26 import java.util.concurrent.Executors;
  27 import java.util.concurrent.ScheduledExecutorService;
  28 import java.util.concurrent.ScheduledFuture;
  29 import java.util.concurrent.ThreadFactory;
  30 import java.util.concurrent.TimeUnit;
  31 import org.apache.commons.lang3.BooleanUtils;
  32 import org.opendaylight.lispflowmapping.config.ConfigIni;
  33 import org.opendaylight.lispflowmapping.implementation.util.LoggingUtil;
  34 import org.opendaylight.lispflowmapping.implementation.util.MSNotificationInputUtil;
  35 import org.opendaylight.lispflowmapping.interfaces.dao.SubKeys;
  36 import org.opendaylight.lispflowmapping.interfaces.dao.Subscriber;
  37 import org.opendaylight.lispflowmapping.interfaces.lisp.IMapNotifyHandler;
  38 import org.opendaylight.lispflowmapping.interfaces.lisp.IMapServerAsync;
  39 import org.opendaylight.lispflowmapping.interfaces.lisp.ISmrNotificationListener;
  40 import org.opendaylight.lispflowmapping.interfaces.lisp.SmrEvent;
  41 import org.opendaylight.lispflowmapping.interfaces.mappingservice.IMappingService;
  42 import org.opendaylight.lispflowmapping.lisp.authentication.LispAuthenticationUtil;
  43 import org.opendaylight.lispflowmapping.lisp.type.LispMessage;
  44 import org.opendaylight.lispflowmapping.lisp.type.MappingData;
  45 import org.opendaylight.lispflowmapping.lisp.util.LispAddressStringifier;
  46 import org.opendaylight.lispflowmapping.lisp.util.LispAddressUtil;
  47 import org.opendaylight.lispflowmapping.lisp.util.MapNotifyBuilderHelper;
  48 import org.opendaylight.lispflowmapping.lisp.util.MapRequestUtil;
  49 import org.opendaylight.lispflowmapping.lisp.util.MappingRecordUtil;
  50 import org.opendaylight.lispflowmapping.lisp.util.MaskUtil;
  51 import org.opendaylight.lispflowmapping.lisp.util.SourceDestKeyHelper;
  52 import org.opendaylight.mdsal.binding.api.NotificationService;
  53 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.PortNumber;
  54 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.lisp.address.types.rev151105.lisp.address.Address;
  55 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.lisp.address.types.rev151105.lisp.address.address.SourceDestKey;
  56 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.inet.binary.types.rev160303.IpAddressBinary;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.binary.address.types.rev160504.augmented.lisp.address.address.Ipv4PrefixBinary;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.binary.address.types.rev160504.augmented.lisp.address.address.Ipv4PrefixBinaryBuilder;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.binary.address.types.rev160504.augmented.lisp.address.address.Ipv6PrefixBinary;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.binary.address.types.rev160504.augmented.lisp.address.address.Ipv6PrefixBinaryBuilder;
  61 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.MapRegister;
  62 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.SiteId;
  63 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.eid.container.Eid;
  64 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.eid.container.EidBuilder;
  65 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.eid.list.EidItem;
  66 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.eid.list.EidItemBuilder;
  67 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapnotifymessage.MapNotifyBuilder;
  68 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping._record.container.MappingRecord;
  69 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping._record.list.MappingRecordItem;
  70 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping._record.list.MappingRecordItemBuilder;
  71 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping._record.list.MappingRecordItemKey;
  72 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.mapping.authkey.container.MappingAuthkey;
  73 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.maprequestnotification.MapRequestBuilder;
  74 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.transport.address.TransportAddress;
  75 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.proto.rev151105.transport.address.TransportAddressBuilder;
  76 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.MappingChanged;
  77 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.MappingOrigin;
  78 import org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.mappingservice.rev150906.OdlMappingserviceListener;
  79 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  80 import org.slf4j.Logger;
  81 import org.slf4j.LoggerFactory;
  82
  83 public class MapServer implements IMapServerAsync, OdlMappingserviceListener, ISmrNotificationListener {
  84
  85     private static final Logger LOG = LoggerFactory.getLogger(MapServer.class);
  86     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};
  87     private final IMappingService mapService;
  88     private boolean subscriptionService;
  89     private final IMapNotifyHandler notifyHandler;
  90     private final NotificationService notificationService;
  91     private ListenerRegistration<MapServer> mapServerListenerRegistration;
  92     private final SmrScheduler scheduler;
  93
  94     public MapServer(IMappingService mapService, boolean subscriptionService,
  95                      IMapNotifyHandler notifyHandler, NotificationService notificationService) {
  96         this.mapService = requireNonNull(mapService);
  97         this.subscriptionService = subscriptionService;
  98         this.notifyHandler = notifyHandler;
  99         this.notificationService = notificationService;
 100         if (notificationService != null) {
 101             notificationService.registerNotificationListener(this);
 102         }
 103         scheduler = new SmrScheduler();
 104     }
 105
 106     @Override
 107     public void setSubscriptionService(boolean subscriptionService) {
 108         this.subscriptionService = subscriptionService;
 109     }
 110
 111     @Override
 112     @SuppressWarnings("unchecked")
 113     public void handleMapRegister(MapRegister mapRegister) {
 114         boolean mappingUpdated = false;
 115         boolean merge = ConfigIni.getInstance().mappingMergeIsSet() && mapRegister.getMergeEnabled();
 116         MappingRecord oldMapping;
 117
 118         if (merge) {
 119             if (!mapRegister.getXtrSiteIdPresent() || mapRegister.getXtrId() == null) {
 120                 LOG.error("Merge bit is set in Map-Register, but xTR-ID is not present. Will not merge.");
 121                 merge = false;
 122             } else if (Arrays.equals(mapRegister.getXtrId().getValue(), ALL_ZEROES_XTR_ID)) {
 123                 LOG.warn("Merge bit is set in Map-Register, but xTR-ID is all zeroes.");
 124             }
 125         }
 126
 127         for (MappingRecordItem record : mapRegister.getMappingRecordItem()) {
 128             MappingRecord mapping = record.getMappingRecord();
 129             Eid eid = mapping.getEid();
 130             MappingData mappingData = new MappingData(mapping, System.currentTimeMillis());
 131             mappingData.setMergeEnabled(merge);
 132             mappingData.setXtrId(mapRegister.getXtrId());
 133
 134             oldMapping = getMappingRecord(mapService.getMapping(MappingOrigin.Southbound, eid));
 135             mapService.addMapping(MappingOrigin.Southbound, eid, getSiteId(mapRegister), mappingData);
 136             if (merge) {
 137                 MappingRecord newMapping = getMappingRecord(mapService.getMapping(MappingOrigin.Southbound, eid));
 138                 if (MappingRecordUtil.mappingChanged(oldMapping, newMapping)) {
 139                     // If there is a SB mapping change with merge on, Map-Notify will be sent to ALL xTRs, not jus the
 140                     // one registering (merging is done in the MappingSystem code)
 141                     mappingUpdated = true;
 142                 }
 143             }
 144         }
 145         if (BooleanUtils.isTrue(mapRegister.getWantMapNotify())) {
 146             LOG.trace("MapRegister wants MapNotify");
 147             MapNotifyBuilder builder = new MapNotifyBuilder();
 148             List<TransportAddress> rlocs = null;
 149             if (merge) {
 150                 Set<IpAddressBinary> notifyRlocs = new LinkedHashSet<>();
 151                 List<MappingRecordItem> mergedMappings = new ArrayList<>();
 152                 for (MappingRecordItem record : mapRegister.getMappingRecordItem()) {
 153                     MappingRecord mapping = record.getMappingRecord();
 154                     MappingRecord currentRecord = getMappingRecord(mapService.getMapping(MappingOrigin.Southbound,
 155                             mapping.getEid()));
 156                     mergedMappings.add(new MappingRecordItemBuilder()
 157                             .withKey(new MappingRecordItemKey(LispAddressStringifier.getString(mapping.getEid())))
 158                             .setMappingRecord(currentRecord).build());
 159                     Set<IpAddressBinary> sourceRlocs = (Set<IpAddressBinary>) mapService.getData(
 160                             MappingOrigin.Southbound, mapping.getEid(), SubKeys.SRC_RLOCS);
 161                     if (sourceRlocs != null) {
 162                         notifyRlocs.addAll(sourceRlocs);
 163                     }
 164                 }
 165                 MapNotifyBuilderHelper.setFromMapRegisterAndMappingRecordItems(builder, mapRegister, mergedMappings);
 166                 // send map-notify to merge group only when mapping record is changed
 167                 if (mappingUpdated) {
 168                     rlocs = getTransportAddresses(notifyRlocs);
 169                 }
 170             } else {
 171                 MapNotifyBuilderHelper.setFromMapRegister(builder, mapRegister);
 172             }
 173             List<MappingRecordItem> mappings = builder.getMappingRecordItem();
 174             if (mappings != null && mappings.get(0) != null && mappings.get(0).getMappingRecord() != null
 175                     && mappings.get(0).getMappingRecord().getEid() != null) {
 176                 MappingAuthkey authkey = mapService.getAuthenticationKey(mappings.get(0).getMappingRecord().getEid());
 177                 if (authkey != null) {
 178                     builder.setAuthenticationData(LispAuthenticationUtil.createAuthenticationData(builder.build(),
 179                             authkey.getKeyString()));
 180                 }
 181             }
 182             notifyHandler.handleMapNotify(builder.build(), rlocs);
 183         }
 184     }
 185
 186     private static List<TransportAddress> getTransportAddresses(Set<IpAddressBinary> addresses) {
 187         List<TransportAddress> rlocs = new ArrayList<>();
 188         for (IpAddressBinary address : addresses) {
 189             TransportAddressBuilder tab = new TransportAddressBuilder();
 190             tab.setIpAddress(address);
 191             tab.setPort(new PortNumber(LispMessage.PORT_NUMBER));
 192             rlocs.add(tab.build());
 193         }
 194         return rlocs;
 195     }
 196
 197     private static SiteId getSiteId(MapRegister mapRegister) {
 198         return mapRegister.getSiteId() != null ? new SiteId(mapRegister.getSiteId()) : null;
 199     }
 200
 201     private static MappingRecord getMappingRecord(MappingData mappingData) {
 202         return mappingData != null ? mappingData.getRecord() : null;
 203     }
 204
 205     @Override
 206     public void onMappingChanged(MappingChanged notification) {
 207         if (subscriptionService) {
 208             Eid eid = notification.getEid();
 209             if (eid == null) {
 210                 eid = notification.getMappingRecord().getEid();
 211             }
 212             LOG.trace("MappingChanged event for {} of type: `{}'", LispAddressStringifier.getString(eid),
 213                     notification.getChangeType());
 214             Set<Subscriber> subscribers = MSNotificationInputUtil.toSubscriberSet(notification.getSubscriberItem());
 215             LoggingUtil.logSubscribers(LOG, eid, subscribers);
 216             if (mapService.isMaster()) {
 217                 sendSmrs(eid, subscribers);
 218                 if (eid.getAddress() instanceof SourceDestKey) {
 219                     Set<Subscriber> dstSubscribers = MSNotificationInputUtil.toSubscriberSetFromDst(
 220                             notification.getDstSubscriberItem());
 221                     LoggingUtil.logSubscribers(LOG, SourceDestKeyHelper.getDstBinary(eid), dstSubscribers);
 222                     sendSmrs(SourceDestKeyHelper.getDstBinary(eid), dstSubscribers);
 223                 }
 224             }
 225         }
 226     }
 227
 228     private void handleSmr(Eid eid, Set<Subscriber> subscribers) {
 229         sendSmrs(eid, subscribers);
 230
 231         // For SrcDst LCAF also send SMRs to Dst prefix
 232         if (eid.getAddress() instanceof SourceDestKey) {
 233             Eid dstAddr = SourceDestKeyHelper.getDstBinary(eid);
 234             Set<Subscriber> dstSubs = mapService.getSubscribers(dstAddr);
 235             sendSmrs(dstAddr, dstSubs);
 236         }
 237     }
 238
 239     private void sendSmrs(Eid eid, Set<Subscriber> subscribers) {
 240         if (subscribers == null) {
 241             return;
 242         }
 243         final MapRequestBuilder mrb = MapRequestUtil.prepareSMR(eid, LispAddressUtil.toRloc(getLocalAddress()));
 244         LOG.trace("Built SMR packet template (EID field will be set later): {}", mrb.build());
 245
 246         scheduler.scheduleSmrs(mrb, subscribers.iterator());
 247     }
 248
 249     private static InetAddress getLocalAddress() {
 250         try {
 251             Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
 252             while (interfaces.hasMoreElements()) {
 253                 NetworkInterface current = interfaces.nextElement();
 254                 LOG.trace("Interface {}", current);
 255                 if (!current.isUp() || current.isLoopback() || current.isVirtual()) {
 256                     continue;
 257                 }
 258                 Enumeration<InetAddress> addresses = current.getInetAddresses();
 259                 while (addresses.hasMoreElements()) {
 260                     InetAddress currentAddr = addresses.nextElement();
 261                     // Skip loopback and link local addresses
 262                     if (currentAddr.isLoopbackAddress() || currentAddr.isLinkLocalAddress()) {
 263                         continue;
 264                     }
 265                     LOG.debug(currentAddr.getHostAddress());
 266                     return currentAddr;
 267                 }
 268             }
 269         } catch (SocketException se) {
 270             LOG.debug("Caught socket exception", se);
 271         }
 272         return null;
 273     }
 274
 275     @Override
 276     public void onSmrInvokedReceived(SmrEvent event) {
 277         scheduler.smrReceived(event);
 278     }
 279
 280     /**
 281      * Task scheduler is responsible for resending SMR messages to a subscriber (xTR)
 282      * {@value ConfigIni#LISP_SMR_RETRY_COUNT} times, or until {@link ISmrNotificationListener#onSmrInvokedReceived}
 283      * is triggered.
 284      */
 285     private final class SmrScheduler {
 286         final int cpuCores = Runtime.getRuntime().availableProcessors();
 287         private final ThreadFactory threadFactory = new ThreadFactoryBuilder()
 288                 .setNameFormat("smr-executor-%d").build();
 289         private final ScheduledExecutorService executor = Executors.newScheduledThreadPool(cpuCores * 2, threadFactory);
 290         private final Map<Eid, Map<Subscriber, ScheduledFuture<?>>> eidFutureMap = new ConcurrentHashMap<>();
 291
 292         void scheduleSmrs(MapRequestBuilder mrb, Iterator<Subscriber> subscribers) {
 293             final Eid srcEid = fixSrcEidMask(mrb.getSourceEid().getEid());
 294             cancelExistingFuturesForEid(srcEid);
 295
 296             final Map<Subscriber, ScheduledFuture<?>> subscriberFutureMap = new ConcurrentHashMap<>();
 297
 298             // Using Iterator ensures that we don't get a ConcurrentModificationException when removing a Subscriber
 299             // from a Set.
 300             while (subscribers.hasNext()) {
 301                 Subscriber subscriber = subscribers.next();
 302                 if (subscriber.timedOut()) {
 303                     LOG.debug("Lazy removing expired subscriber entry {}", subscriber.getString());
 304                     subscribers.remove();
 305                 } else {
 306                     final ScheduledFuture<?> future = executor.scheduleAtFixedRate(new CancellableRunnable(
 307                             mrb, subscriber), 0L, ConfigIni.getInstance().getSmrTimeout(), TimeUnit.MILLISECONDS);
 308                     subscriberFutureMap.put(subscriber, future);
 309                 }
 310             }
 311
 312             if (subscriberFutureMap.isEmpty()) {
 313                 return;
 314             }
 315             eidFutureMap.put(srcEid, subscriberFutureMap);
 316         }
 317
 318         void smrReceived(SmrEvent event) {
 319             final List<Subscriber> subscriberList = event.getSubscriberList();
 320             for (Subscriber subscriber : subscriberList) {
 321                 if (LOG.isTraceEnabled()) {
 322                     LOG.trace("SMR-invoked event, EID {}, subscriber {}",
 323                             LispAddressStringifier.getString(event.getEid()),
 324                             subscriber.getString());
 325                     LOG.trace("eidFutureMap: {}", eidFutureMap);
 326                 }
 327                 final Map<Subscriber, ScheduledFuture<?>> subscriberFutureMap = eidFutureMap.get(event.getEid());
 328                 if (subscriberFutureMap != null) {
 329                     final ScheduledFuture<?> future = subscriberFutureMap.get(subscriber);
 330                     if (future != null && !future.isCancelled()) {
 331                         future.cancel(true);
 332                         if (LOG.isDebugEnabled()) {
 333                             LOG.debug("SMR-invoked MapRequest received, scheduled task for subscriber {}, EID {} with"
 334                                     + " nonce {} has been cancelled", subscriber.getString(),
 335                                     LispAddressStringifier.getString(event.getEid()), event.getNonce());
 336                         }
 337                         subscriberFutureMap.remove(subscriber);
 338                     } else {
 339                         if (future == null) {
 340                             LOG.trace("No outstanding SMR tasks for EID {}, subscriber {}",
 341                                     LispAddressStringifier.getString(event.getEid()), subscriber.getString());
 342                         } else {
 343                             LOG.trace("Future {} is cancelled", future);
 344                         }
 345                     }
 346                     if (subscriberFutureMap.isEmpty()) {
 347                         eidFutureMap.remove(event.getEid());
 348                     }
 349                 } else {
 350                     if (LOG.isTraceEnabled()) {
 351                         LOG.trace("No outstanding SMR tasks for EID {}",
 352                                 LispAddressStringifier.getString(event.getEid()));
 353                     }
 354                 }
 355             }
 356         }
 357
 358         private void cancelExistingFuturesForEid(Eid eid) {
 359             synchronized (eidFutureMap) {
 360                 if (eidFutureMap.containsKey(eid)) {
 361                     final Map<Subscriber, ScheduledFuture<?>> subscriberFutureMap = eidFutureMap.get(eid);
 362                     Iterator<Subscriber> oldSubscribers = subscriberFutureMap.keySet().iterator();
 363                     while (oldSubscribers.hasNext()) {
 364                         Subscriber subscriber = oldSubscribers.next();
 365                         ScheduledFuture<?> subscriberFuture = subscriberFutureMap.get(subscriber);
 366                         subscriberFuture.cancel(true);
 367                     }
 368                     eidFutureMap.remove(eid);
 369                 }
 370             }
 371         }
 372
 373         /*
 374          * See https://bugs.opendaylight.org/show_bug.cgi?id=8469#c1 why this is necessary.
 375          *
 376          * TL;DR  The sourceEid field in the MapRequestBuilder object will be serialized to a packet on the wire, and
 377          * a Map-Request can't store the prefix length in the source EID.
 378          *
 379          * Since we store all prefixes as binary internally, we only care about and fix those address types.
 380          */
 381         private Eid fixSrcEidMask(Eid eid) {
 382             Address address = eid.getAddress();
 383             if (address instanceof Ipv4PrefixBinary) {
 384                 return new EidBuilder(eid).setAddress(new Ipv4PrefixBinaryBuilder((Ipv4PrefixBinary) address)
 385                         .setIpv4MaskLength(MaskUtil.IPV4_MAX_MASK_UINT).build()).build();
 386             } else if (address instanceof Ipv6PrefixBinary) {
 387                 return new EidBuilder(eid).setAddress(new Ipv6PrefixBinaryBuilder((Ipv6PrefixBinary) address)
 388                         .setIpv6MaskLength(MaskUtil.IPV6_MAX_MASK_UINT).build()).build();
 389             }
 390             return eid;
 391         }
 392
 393         private final class CancellableRunnable implements Runnable {
 394             private final MapRequestBuilder mrb;
 395             private final Subscriber subscriber;
 396             private int executionCount = 1;
 397
 398             CancellableRunnable(MapRequestBuilder mrb, Subscriber subscriber) {
 399                 this.mrb = mrb;
 400                 this.subscriber = subscriber;
 401             }
 402
 403             @SuppressWarnings("checkstyle:IllegalCatch")
 404             @Override
 405             public void run() {
 406                 final Eid srcEid = mrb.getSourceEid().getEid();
 407
 408                 try {
 409                     // The address stored in the SMR's EID record is used as Source EID in the SMR-invoked
 410                     // Map-Request. To ensure consistent behavior it is set to the value used to originally request
 411                     // a given mapping.
 412                     if (executionCount <= ConfigIni.getInstance().getSmrRetryCount()) {
 413                         synchronized (mrb) {
 414                             mrb.setEidItem(new ArrayList<EidItem>());
 415                             mrb.getEidItem().add(new EidItemBuilder()
 416                                     .setEidItemId(LispAddressStringifier.getString(subscriber.getSrcEid()))
 417                                     .setEid(subscriber.getSrcEid()).build());
 418                             notifyHandler.handleSMR(mrb.build(), subscriber.getSrcRloc());
 419                             if (LOG.isTraceEnabled()) {
 420                                 LOG.trace("Attempt #{} to send SMR to subscriber {} for EID {}",
 421                                         executionCount,
 422                                         subscriber.getString(),
 423                                         LispAddressStringifier.getString(mrb.getSourceEid().getEid()));
 424                             }
 425                         }
 426                     } else {
 427                         LOG.trace("Cancelling execution of a SMR Map-Request after {} failed attempts.",
 428                                 executionCount - 1);
 429                         cancelAndRemove(subscriber, srcEid);
 430                         return;
 431                     }
 432                 } catch (Exception e) {
 433                     LOG.error("Errors encountered while handling SMR:", e);
 434                     cancelAndRemove(subscriber, srcEid);
 435                     return;
 436                 }
 437                 executionCount++;
 438             }
 439
 440             private void cancelAndRemove(Subscriber sub, Eid eid) {
 441                 final Map<Subscriber, ScheduledFuture<?>> subscriberFutureMap = eidFutureMap.get(eid);
 442                 if (subscriberFutureMap == null) {
 443                     LOG.warn("Couldn't find subscriber {} in SMR scheduler internal list", sub);
 444                     return;
 445                 }
 446
 447                 if (subscriberFutureMap.containsKey(sub)) {
 448                     ScheduledFuture<?> eidFuture = subscriberFutureMap.get(sub);
 449                     subscriberFutureMap.remove(sub);
 450                     eidFuture.cancel(false);
 451                 }
 452                 if (subscriberFutureMap.isEmpty()) {
 453                     eidFutureMap.remove(eid);
 454                 }
 455             }
 456         }
 457     }
 458 }