opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractShardBackendResolver.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.primitives.UnsignedLong;
  15 import java.util.concurrent.CompletionStage;
  16 import java.util.concurrent.TimeUnit;
  17 import java.util.concurrent.atomic.AtomicLong;
  18 import javax.annotation.Nonnull;
  19 import javax.annotation.Nullable;
  20 import javax.annotation.concurrent.GuardedBy;
  21 import javax.annotation.concurrent.ThreadSafe;
  22 import org.opendaylight.controller.cluster.access.ABIVersion;
  23 import org.opendaylight.controller.cluster.access.client.BackendInfoResolver;
  24 import org.opendaylight.controller.cluster.access.commands.ConnectClientRequest;
  25 import org.opendaylight.controller.cluster.access.commands.ConnectClientSuccess;
  26 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
  27 import org.opendaylight.controller.cluster.access.concepts.RequestFailure;
  28 import org.opendaylight.controller.cluster.common.actor.ExplicitAsk;
  29 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32 import scala.Function1;
  33 import scala.compat.java8.FutureConverters;
  34
  35 /**
  36  * {@link BackendInfoResolver} implementation for static shard configuration based on ShardManager. Each string-named
  37  * shard is assigned a single cookie and this mapping is stored in a bidirectional map. Information about corresponding
  38  * shard leader is resolved via {@link ActorContext}. The product of resolution is {@link ShardBackendInfo}.
  39  *
  40  * @author Robert Varga
  41  */
  42 @ThreadSafe
  43 abstract class AbstractShardBackendResolver extends BackendInfoResolver<ShardBackendInfo> {
  44     static final class ShardState {
  45         private final CompletionStage<ShardBackendInfo> stage;
  46         @GuardedBy("this")
  47         private ShardBackendInfo result;
  48
  49         ShardState(final CompletionStage<ShardBackendInfo> stage) {
  50             this.stage = Preconditions.checkNotNull(stage);
  51             stage.whenComplete(this::onStageResolved);
  52         }
  53
  54         @Nonnull CompletionStage<ShardBackendInfo> getStage() {
  55             return stage;
  56         }
  57
  58         @Nullable synchronized ShardBackendInfo getResult() {
  59             return result;
  60         }
  61
  62         private synchronized void onStageResolved(final ShardBackendInfo result, final Throwable failure) {
  63             if (failure == null) {
  64                 this.result = Preconditions.checkNotNull(result);
  65             } else {
  66                 LOG.warn("Failed to resolve shard", failure);
  67             }
  68         }
  69     }
  70
  71     private static final Logger LOG = LoggerFactory.getLogger(AbstractShardBackendResolver.class);
  72
  73     /**
  74      * Fall-over-dead timeout. If we do not make progress in this long, just fall over and propagate the failure.
  75      * All users are expected to fail, possibly attempting to recover by restarting. It is fair to remain
  76      * non-operational.
  77      */
  78     // TODO: maybe make this configurable somehow?
  79     private static final Timeout DEAD_TIMEOUT = Timeout.apply(15, TimeUnit.MINUTES);
  80
  81     private final AtomicLong nextSessionId = new AtomicLong();
  82     private final Function1<ActorRef, ?> connectFunction;
  83     private final ActorContext actorContext;
  84
  85     // FIXME: we really need just ActorContext.findPrimaryShardAsync()
  86     AbstractShardBackendResolver(final ClientIdentifier clientId, final ActorContext actorContext) {
  87         this.actorContext = Preconditions.checkNotNull(actorContext);
  88         this.connectFunction = ExplicitAsk.toScala(t -> new ConnectClientRequest(clientId, t, ABIVersion.BORON,
  89             ABIVersion.current()));
  90     }
  91
  92     protected final void flushCache(final String shardName) {
  93         actorContext.getPrimaryShardInfoCache().remove(shardName);
  94     }
  95
  96     protected final ShardState resolveBackendInfo(final String shardName, final long cookie) {
  97         LOG.debug("Resolving cookie {} to shard {}", cookie, shardName);
  98
  99         return new ShardState(FutureConverters.toJava(actorContext.findPrimaryShardAsync(shardName)).thenCompose(i -> {
 100             LOG.debug("Looking up primary info for {} from {}", shardName, i);
 101             return FutureConverters.toJava(ExplicitAsk.ask(i.getPrimaryShardActor(), connectFunction, DEAD_TIMEOUT));
 102         }).thenApply(response -> {
 103             if (response instanceof RequestFailure) {
 104                 final RequestFailure<?, ?> failure = (RequestFailure<?, ?>) response;
 105                 LOG.debug("Connect request failed {}", failure, failure.getCause());
 106                 throw Throwables.propagate(failure.getCause());
 107             }
 108
 109             LOG.debug("Resolved backend information to {}", response);
 110
 111             Preconditions.checkArgument(response instanceof ConnectClientSuccess, "Unhandled response {}", response);
 112             final ConnectClientSuccess success = (ConnectClientSuccess) response;
 113
 114             return new ShardBackendInfo(success.getBackend(),
 115                 nextSessionId.getAndIncrement(), success.getVersion(), shardName, UnsignedLong.fromLongBits(cookie),
 116                 success.getDataTree(), success.getMaxMessages());
 117         }));
 118     }
 119 }