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