opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/ModuleShardBackendResolver.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.controller.cluster.databroker.actors.dds;
   9
  10 import akka.actor.ActorRef;
  11 import akka.util.Timeout;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.base.Throwables;
  14 import com.google.common.collect.BiMap;
  15 import com.google.common.collect.ImmutableBiMap;
  16 import com.google.common.collect.ImmutableBiMap.Builder;
  17 import com.google.common.primitives.UnsignedLong;
  18 import java.util.concurrent.CompletableFuture;
  19 import java.util.concurrent.CompletionStage;
  20 import java.util.concurrent.TimeUnit;
  21 import java.util.concurrent.atomic.AtomicLong;
  22 import javax.annotation.concurrent.GuardedBy;
  23 import org.opendaylight.controller.cluster.access.ABIVersion;
  24 import org.opendaylight.controller.cluster.access.client.BackendInfo;
  25 import org.opendaylight.controller.cluster.access.client.BackendInfoResolver;
  26 import org.opendaylight.controller.cluster.access.commands.ConnectClientRequest;
  27 import org.opendaylight.controller.cluster.access.commands.ConnectClientSuccess;
  28 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
  29 import org.opendaylight.controller.cluster.access.concepts.RequestFailure;
  30 import org.opendaylight.controller.cluster.common.actor.ExplicitAsk;
  31 import org.opendaylight.controller.cluster.datastore.shardstrategy.DefaultShardStrategy;
  32 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  33 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36 import scala.Function1;
  37 import scala.compat.java8.FutureConverters;
  38
  39 /**
  40  * {@link BackendInfoResolver} implementation for static shard configuration based on ShardManager. Each string-named
  41  * shard is assigned a single cookie and this mapping is stored in a bidirectional map. Information about corresponding
  42  * shard leader is resolved via {@link ActorContext}. The product of resolution is {@link ShardBackendInfo}.
  43  *
  44  * @author Robert Varga
  45  */
  46 final class ModuleShardBackendResolver extends BackendInfoResolver<ShardBackendInfo> {
  47     private static final CompletableFuture<ShardBackendInfo> NULL_FUTURE = CompletableFuture.completedFuture(null);
  48     private static final Logger LOG = LoggerFactory.getLogger(ModuleShardBackendResolver.class);
  49
  50     /**
  51      * Fall-over-dead timeout. If we do not make progress in this long, just fall over and propagate the failure.
  52      * All users are expected to fail, possibly attempting to recover by restarting. It is fair to remain
  53      * non-operational.
  54      */
  55     // TODO: maybe make this configurable somehow?
  56     private static final Timeout DEAD_TIMEOUT = Timeout.apply(15, TimeUnit.MINUTES);
  57
  58     private final ActorContext actorContext;
  59     // FIXME: this counter should be in superclass somewhere
  60     private final AtomicLong nextSessionId = new AtomicLong();
  61     private final Function1<ActorRef, ?> connectFunction;
  62
  63     @GuardedBy("this")
  64     private long nextShard = 1;
  65
  66     private volatile BiMap<String, Long> shards = ImmutableBiMap.of(DefaultShardStrategy.DEFAULT_SHARD, 0L);
  67
  68     // FIXME: we really need just ActorContext.findPrimaryShardAsync()
  69     ModuleShardBackendResolver(final ClientIdentifier clientId, final ActorContext actorContext) {
  70         this.actorContext = Preconditions.checkNotNull(actorContext);
  71         this.connectFunction = ExplicitAsk.toScala(t -> new ConnectClientRequest(clientId, t, ABIVersion.BORON,
  72             ABIVersion.current()));
  73     }
  74
  75     @Override
  76     protected void invalidateBackendInfo(final CompletionStage<? extends BackendInfo> info) {
  77         LOG.trace("Initiated invalidation of backend information {}", info);
  78         info.thenAccept(this::invalidate);
  79     }
  80
  81     private void invalidate(final BackendInfo result) {
  82         Preconditions.checkArgument(result instanceof ShardBackendInfo);
  83         LOG.debug("Invalidating backend information {}", result);
  84         actorContext.getPrimaryShardInfoCache().remove(((ShardBackendInfo)result).getShardName());
  85     }
  86
  87     Long resolveShardForPath(final YangInstanceIdentifier path) {
  88         final String shardName = actorContext.getShardStrategyFactory().getStrategy(path).findShard(path);
  89         Long cookie = shards.get(shardName);
  90         if (cookie == null) {
  91             synchronized (this) {
  92                 cookie = shards.get(shardName);
  93                 if (cookie == null) {
  94                     cookie = nextShard++;
  95
  96                     Builder<String, Long> builder = ImmutableBiMap.builder();
  97                     builder.putAll(shards);
  98                     builder.put(shardName, cookie);
  99                     shards = builder.build();
 100                 }
 101             }
 102         }
 103
 104         return cookie;
 105     }
 106
 107     @Override
 108     protected CompletableFuture<ShardBackendInfo> resolveBackendInfo(final Long cookie) {
 109         final String shardName = shards.inverse().get(cookie);
 110         if (shardName == null) {
 111             LOG.warn("Failing request for non-existent cookie {}", cookie);
 112             return NULL_FUTURE;
 113         }
 114
 115         final CompletableFuture<ShardBackendInfo> ret = new CompletableFuture<>();
 116
 117         FutureConverters.toJava(actorContext.findPrimaryShardAsync(shardName)).thenCompose(info -> {
 118             LOG.debug("Looking up primary info for {} from {}", shardName, info);
 119             return FutureConverters.toJava(ExplicitAsk.ask(info.getPrimaryShardActor(), connectFunction, DEAD_TIMEOUT));
 120         }).thenApply(response -> {
 121             if (response instanceof RequestFailure) {
 122                 final RequestFailure<?, ?> failure = (RequestFailure<?, ?>) response;
 123                 LOG.debug("Connect request failed {}", failure, failure.getCause());
 124                 throw Throwables.propagate(failure.getCause());
 125             }
 126
 127             LOG.debug("Resolved backend information to {}", response);
 128
 129             Preconditions.checkArgument(response instanceof ConnectClientSuccess, "Unhandled response {}", response);
 130             final ConnectClientSuccess success = (ConnectClientSuccess) response;
 131
 132             return new ShardBackendInfo(success.getBackend(),
 133                 nextSessionId.getAndIncrement(), success.getVersion(), shardName, UnsignedLong.fromLongBits(cookie),
 134                 success.getDataTree(), success.getMaxMessages());
 135         }).whenComplete((info, throwablw) -> {
 136             if (throwablw != null) {
 137                 ret.completeExceptionally(throwablw);
 138             } else {
 139                 ret.complete(info);
 140             }
 141         });
 142
 143         LOG.debug("Resolving cookie {} to shard {}", cookie, shardName);
 144         return ret;
 145     }
 146 }