singleton-service/mdsal-singleton-dom-impl/src/main/java/org/opendaylight/mdsal/singleton/dom/impl/EOSClusterSingletonServiceProvider.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, 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 package org.opendaylight.mdsal.singleton.dom.impl;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static com.google.common.base.Verify.verify;
  12 import static com.google.common.base.Verify.verifyNotNull;
  13 import static java.util.Objects.requireNonNull;
  14
  15 import com.google.common.annotations.VisibleForTesting;
  16 import com.google.common.base.Strings;
  17 import com.google.common.util.concurrent.Futures;
  18 import com.google.common.util.concurrent.ListenableFuture;
  19 import com.google.common.util.concurrent.MoreExecutors;
  20 import java.util.ArrayList;
  21 import java.util.List;
  22 import java.util.concurrent.ConcurrentHashMap;
  23 import java.util.concurrent.ConcurrentMap;
  24 import java.util.concurrent.ExecutionException;
  25 import javax.annotation.PreDestroy;
  26 import javax.inject.Inject;
  27 import javax.inject.Singleton;
  28 import org.eclipse.jdt.annotation.NonNull;
  29 import org.opendaylight.mdsal.eos.common.api.CandidateAlreadyRegisteredException;
  30 import org.opendaylight.mdsal.eos.common.api.EntityOwnershipStateChange;
  31 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  32 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipListener;
  33 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipService;
  34 import org.opendaylight.mdsal.singleton.common.api.ClusterSingletonService;
  35 import org.opendaylight.mdsal.singleton.common.api.ClusterSingletonServiceProvider;
  36 import org.opendaylight.yangtools.concepts.Registration;
  37 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  38 import org.osgi.service.component.annotations.Activate;
  39 import org.osgi.service.component.annotations.Component;
  40 import org.osgi.service.component.annotations.Deactivate;
  41 import org.osgi.service.component.annotations.Reference;
  42 import org.slf4j.Logger;
  43 import org.slf4j.LoggerFactory;
  44
  45 /**
  46  * Implementation of {@link ClusterSingletonServiceProvider} working on top a {@link DOMEntityOwnershipService}.
  47  */
  48 @Singleton
  49 @Component(service = ClusterSingletonServiceProvider.class)
  50 public final class EOSClusterSingletonServiceProvider
  51         implements ClusterSingletonServiceProvider, DOMEntityOwnershipListener, AutoCloseable {
  52     private static final Logger LOG = LoggerFactory.getLogger(EOSClusterSingletonServiceProvider.class);
  53
  54     @VisibleForTesting
  55     static final @NonNull String SERVICE_ENTITY_TYPE = "org.opendaylight.mdsal.ServiceEntityType";
  56     @VisibleForTesting
  57     static final @NonNull String CLOSE_SERVICE_ENTITY_TYPE = "org.opendaylight.mdsal.AsyncServiceCloseEntityType";
  58
  59     private final ConcurrentMap<String, ClusterSingletonServiceGroup> serviceGroupMap = new ConcurrentHashMap<>();
  60     private final DOMEntityOwnershipService entityOwnershipService;
  61
  62     /* EOS Entity Listeners Registration */
  63     private Registration serviceEntityListenerReg;
  64     private Registration asyncCloseEntityListenerReg;
  65
  66     @Inject
  67     @Activate
  68     public EOSClusterSingletonServiceProvider(@Reference final DOMEntityOwnershipService entityOwnershipService) {
  69         this.entityOwnershipService = requireNonNull(entityOwnershipService);
  70         serviceEntityListenerReg = entityOwnershipService.registerListener(SERVICE_ENTITY_TYPE, this);
  71         asyncCloseEntityListenerReg = entityOwnershipService.registerListener(CLOSE_SERVICE_ENTITY_TYPE, this);
  72         LOG.info("Cluster Singleton Service started");
  73     }
  74
  75     @PreDestroy
  76     @Deactivate
  77     @Override
  78     public synchronized void close() throws ExecutionException, InterruptedException {
  79         if (serviceEntityListenerReg == null) {
  80             // Idempotent
  81             return;
  82         }
  83
  84         LOG.info("Cluster Singleton Service stopping");
  85         serviceEntityListenerReg.close();
  86         serviceEntityListenerReg = null;
  87
  88         final var future = Futures.allAsList(serviceGroupMap.values().stream()
  89             .map(ClusterSingletonServiceGroup::closeClusterSingletonGroup)
  90             .toList());
  91         try {
  92             LOG.debug("Waiting for service groups to stop");
  93             future.get();
  94         } finally {
  95             asyncCloseEntityListenerReg.close();
  96             asyncCloseEntityListenerReg = null;
  97             serviceGroupMap.clear();
  98         }
  99
 100         LOG.info("Cluster Singleton Service stopped");
 101     }
 102
 103     @Override
 104     public synchronized Registration registerClusterSingletonService(final ClusterSingletonService service) {
 105         LOG.debug("Call registrationService {} method for ClusterSingletonService Provider {}", service, this);
 106
 107         final String serviceIdentifier = service.getIdentifier().getName();
 108         checkArgument(!Strings.isNullOrEmpty(serviceIdentifier),
 109             "ClusterSingletonService identifier may not be null nor empty");
 110
 111         final ClusterSingletonServiceGroup serviceGroup;
 112         final var existing = serviceGroupMap.get(serviceIdentifier);
 113         if (existing == null) {
 114             serviceGroup = createGroup(serviceIdentifier, new ArrayList<>(1));
 115             serviceGroupMap.put(serviceIdentifier, serviceGroup);
 116
 117             try {
 118                 initializeOrRemoveGroup(serviceGroup);
 119             } catch (CandidateAlreadyRegisteredException e) {
 120                 throw new IllegalArgumentException("Service group already registered", e);
 121             }
 122         } else {
 123             serviceGroup = existing;
 124         }
 125
 126         final var reg = new ServiceRegistration(service) {
 127             @Override
 128             protected void removeRegistration() {
 129                 // We need to bounce the unregistration through a ordered lock in order not to deal with asynchronous
 130                 // shutdown of the group and user registering it again.
 131                 EOSClusterSingletonServiceProvider.this.removeRegistration(serviceIdentifier, this);
 132             }
 133         };
 134
 135         serviceGroup.registerService(reg);
 136         return reg;
 137     }
 138
 139     private ClusterSingletonServiceGroup createGroup(final String serviceIdentifier,
 140             final List<ServiceRegistration> services) {
 141         return new ClusterSingletonServiceGroupImpl(serviceIdentifier, entityOwnershipService,
 142             createEntity(SERVICE_ENTITY_TYPE, serviceIdentifier),
 143             createEntity(CLOSE_SERVICE_ENTITY_TYPE, serviceIdentifier), services);
 144     }
 145
 146     private void initializeOrRemoveGroup(final ClusterSingletonServiceGroup group)
 147             throws CandidateAlreadyRegisteredException {
 148         try {
 149             group.initialize();
 150         } catch (CandidateAlreadyRegisteredException e) {
 151             serviceGroupMap.remove(group.getIdentifier(), group);
 152             throw e;
 153         }
 154     }
 155
 156     private void removeRegistration(final String serviceIdentifier, final ServiceRegistration reg) {
 157         final PlaceholderGroup placeHolder;
 158         final ListenableFuture<?> future;
 159         synchronized (this) {
 160             final var lookup = verifyNotNull(serviceGroupMap.get(serviceIdentifier));
 161             future = lookup.unregisterService(reg);
 162             if (future == null) {
 163                 return;
 164             }
 165
 166             // Close the group and replace it with a placeholder
 167             LOG.debug("Closing service group {}", serviceIdentifier);
 168             placeHolder = new PlaceholderGroup(lookup, future);
 169
 170             final String identifier = reg.getInstance().getIdentifier().getName();
 171             verify(serviceGroupMap.replace(identifier, lookup, placeHolder));
 172             LOG.debug("Replaced group {} with {}", serviceIdentifier, placeHolder);
 173
 174             lookup.closeClusterSingletonGroup();
 175         }
 176
 177         future.addListener(() -> finishShutdown(placeHolder), MoreExecutors.directExecutor());
 178     }
 179
 180     private synchronized void finishShutdown(final PlaceholderGroup placeHolder) {
 181         final var identifier = placeHolder.getIdentifier();
 182         LOG.debug("Service group {} closed", identifier);
 183
 184         final var services = placeHolder.getServices();
 185         if (services.isEmpty()) {
 186             // No services, we are all done
 187             if (serviceGroupMap.remove(identifier, placeHolder)) {
 188                 LOG.debug("Service group {} removed", placeHolder);
 189             } else {
 190                 LOG.debug("Service group {} superseded by {}", placeHolder, serviceGroupMap.get(identifier));
 191             }
 192             return;
 193         }
 194
 195         // Placeholder is being retired, we are reusing its services as the seed for the group.
 196         final var group = createGroup(identifier, services);
 197         verify(serviceGroupMap.replace(identifier, placeHolder, group));
 198         placeHolder.setSuccessor(group);
 199         LOG.debug("Service group upgraded from {} to {}", placeHolder, group);
 200
 201         try {
 202             initializeOrRemoveGroup(group);
 203         } catch (CandidateAlreadyRegisteredException e) {
 204             LOG.error("Failed to register delayed group {}, it will remain inoperational", identifier, e);
 205         }
 206     }
 207
 208     @Override
 209     public void ownershipChanged(final DOMEntity entity, final EntityOwnershipStateChange change,
 210             final boolean inJeopardy) {
 211         LOG.debug("Ownership change for ClusterSingletonService Provider on {} {} inJeopardy={}", entity, change,
 212             inJeopardy);
 213
 214         final var serviceIdentifier = getServiceIdentifierFromEntity(entity);
 215         final var serviceHolder = serviceGroupMap.get(serviceIdentifier);
 216         if (serviceHolder != null) {
 217             serviceHolder.ownershipChanged(entity, change, inJeopardy);
 218         } else {
 219             LOG.debug("ClusterSingletonServiceGroup was not found for serviceIdentifier {}", serviceIdentifier);
 220         }
 221     }
 222
 223     @VisibleForTesting
 224     static String getServiceIdentifierFromEntity(final DOMEntity entity) {
 225         final var yii = entity.getIdentifier();
 226         final var niiwp = (NodeIdentifierWithPredicates) yii.getLastPathArgument();
 227         return niiwp.values().iterator().next().toString();
 228     }
 229
 230     /**
 231      * Creates an extended {@link DOMEntity} instance.
 232      *
 233      * @param entityType the type of the entity
 234      * @param entityIdentifier the identifier of the entity
 235      * @return instance of Entity extended GenericEntity type
 236      */
 237     @VisibleForTesting
 238     static DOMEntity createEntity(final String entityType, final String entityIdentifier) {
 239         return new DOMEntity(entityType, entityIdentifier);
 240     }
 241 }