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