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.primitives.UnsignedLong;
  14 import java.util.concurrent.CompletableFuture;
  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.RequestException;
  28 import org.opendaylight.controller.cluster.access.concepts.RequestFailure;
  29 import org.opendaylight.controller.cluster.common.actor.ExplicitAsk;
  30 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  31 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
  32 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
  33 import org.opendaylight.controller.cluster.datastore.messages.PrimaryShardInfo;
  34 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37 import scala.Function1;
  38 import scala.compat.java8.FutureConverters;
  39
  40 /**
  41  * {@link BackendInfoResolver} implementation for static shard configuration based on ShardManager. Each string-named
  42  * shard is assigned a single cookie and this mapping is stored in a bidirectional map. Information about corresponding
  43  * shard leader is resolved via {@link ActorContext}. The product of resolution is {@link ShardBackendInfo}.
  44  *
  45  * @author Robert Varga
  46  */
  47 @ThreadSafe
  48 abstract class AbstractShardBackendResolver extends BackendInfoResolver<ShardBackendInfo> {
  49     static final class ShardState {
  50         private final CompletionStage<ShardBackendInfo> stage;
  51         @GuardedBy("this")
  52         private ShardBackendInfo result;
  53
  54         ShardState(final CompletionStage<ShardBackendInfo> stage) {
  55             this.stage = Preconditions.checkNotNull(stage);
  56             stage.whenComplete(this::onStageResolved);
  57         }
  58
  59         @Nonnull CompletionStage<ShardBackendInfo> getStage() {
  60             return stage;
  61         }
  62
  63         @Nullable synchronized ShardBackendInfo getResult() {
  64             return result;
  65         }
  66
  67         private synchronized void onStageResolved(final ShardBackendInfo result, final Throwable failure) {
  68             if (failure == null) {
  69                 this.result = Preconditions.checkNotNull(result);
  70             } else {
  71                 LOG.warn("Failed to resolve shard", failure);
  72             }
  73         }
  74     }
  75
  76     private static final Logger LOG = LoggerFactory.getLogger(AbstractShardBackendResolver.class);
  77
  78     /**
  79      * Connect request timeout. If the shard does not respond within this interval, we retry the lookup and connection.
  80      */
  81     // TODO: maybe make this configurable somehow?
  82     private static final Timeout CONNECT_TIMEOUT = Timeout.apply(5, TimeUnit.SECONDS);
  83
  84     private final AtomicLong nextSessionId = new AtomicLong();
  85     private final Function1<ActorRef, ?> connectFunction;
  86     private final ActorContext actorContext;
  87
  88     // FIXME: we really need just ActorContext.findPrimaryShardAsync()
  89     AbstractShardBackendResolver(final ClientIdentifier clientId, final ActorContext actorContext) {
  90         this.actorContext = Preconditions.checkNotNull(actorContext);
  91         this.connectFunction = ExplicitAsk.toScala(t -> new ConnectClientRequest(clientId, t, ABIVersion.BORON,
  92             ABIVersion.current()));
  93     }
  94
  95     protected final void flushCache(final String shardName) {
  96         actorContext.getPrimaryShardInfoCache().remove(shardName);
  97     }
  98
  99     protected final ShardState resolveBackendInfo(final String shardName, final long cookie) {
 100         LOG.debug("Resolving cookie {} to shard {}", cookie, shardName);
 101
 102         final CompletableFuture<ShardBackendInfo> future = new CompletableFuture<>();
 103         FutureConverters.toJava(actorContext.findPrimaryShardAsync(shardName)).whenComplete((info, failure) -> {
 104             if (failure == null) {
 105                 connectShard(shardName, cookie, info, future);
 106                 return;
 107             }
 108
 109             LOG.debug("Shard {} failed to resolve", shardName, failure);
 110             if (failure instanceof NoShardLeaderException) {
 111                 // FIXME: this actually is an exception we can retry on
 112                 future.completeExceptionally(failure);
 113             } else if (failure instanceof NotInitializedException) {
 114                 // FIXME: this actually is an exception we can retry on
 115                 LOG.info("Shard {} has not initialized yet", shardName);
 116                 future.completeExceptionally(failure);
 117             } else if (failure instanceof PrimaryNotFoundException) {
 118                 LOG.info("Failed to find primary for shard {}", shardName);
 119                 future.completeExceptionally(failure);
 120             } else {
 121                 future.completeExceptionally(failure);
 122             }
 123         });
 124
 125         return new ShardState(future);
 126     }
 127
 128     private void connectShard(final String shardName, final long cookie, final PrimaryShardInfo info,
 129             final CompletableFuture<ShardBackendInfo> future) {
 130         LOG.debug("Shard {} resolved to {}, attempting to connect", shardName, info);
 131
 132         FutureConverters.toJava(ExplicitAsk.ask(info.getPrimaryShardActor(), connectFunction, CONNECT_TIMEOUT))
 133             .whenComplete((response, failure) -> {
 134                 if (failure != null) {
 135                     LOG.debug("Connect attempt to {} failed", shardName, failure);
 136                     future.completeExceptionally(failure);
 137                     return;
 138                 }
 139                 if (response instanceof RequestFailure) {
 140                     final RequestException cause = ((RequestFailure<?, ?>) response).getCause();
 141                     LOG.debug("Connect attempt to {} failed to process", shardName, cause);
 142                     future.completeExceptionally(cause);
 143                     return;
 144                 }
 145
 146                 LOG.debug("Resolved backend information to {}", response);
 147                 Preconditions.checkArgument(response instanceof ConnectClientSuccess, "Unhandled response {}",
 148                     response);
 149                 final ConnectClientSuccess success = (ConnectClientSuccess) response;
 150                 future.complete(new ShardBackendInfo(success.getBackend(), nextSessionId.getAndIncrement(),
 151                     success.getVersion(), shardName, UnsignedLong.fromLongBits(cookie), success.getDataTree(),
 152                     success.getMaxMessages()));
 153             });
 154     }
 155 }