2 * Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
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
8 package org.opendaylight.controller.cluster.databroker.actors.dds;
10 import akka.actor.ActorRef;
11 import akka.util.Timeout;
12 import com.google.common.base.Preconditions;
13 import com.google.common.primitives.UnsignedLong;
15 import java.util.concurrent.CompletableFuture;
16 import java.util.concurrent.CompletionStage;
17 import java.util.concurrent.ConcurrentHashMap;
18 import java.util.concurrent.TimeUnit;
19 import java.util.concurrent.TimeoutException;
20 import java.util.concurrent.atomic.AtomicLong;
21 import java.util.function.Consumer;
22 import javax.annotation.Nonnull;
23 import javax.annotation.Nullable;
24 import javax.annotation.concurrent.GuardedBy;
25 import javax.annotation.concurrent.ThreadSafe;
26 import org.opendaylight.controller.cluster.access.ABIVersion;
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.commands.NotLeaderException;
31 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
32 import org.opendaylight.controller.cluster.access.concepts.RequestFailure;
33 import org.opendaylight.controller.cluster.common.actor.ExplicitAsk;
34 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
35 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
36 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
37 import org.opendaylight.controller.cluster.datastore.messages.PrimaryShardInfo;
38 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
39 import org.opendaylight.yangtools.concepts.Registration;
40 import org.slf4j.Logger;
41 import org.slf4j.LoggerFactory;
42 import scala.Function1;
43 import scala.compat.java8.FutureConverters;
46 * {@link BackendInfoResolver} implementation for static shard configuration based on ShardManager. Each string-named
47 * shard is assigned a single cookie and this mapping is stored in a bidirectional map. Information about corresponding
48 * shard leader is resolved via {@link ActorContext}. The product of resolution is {@link ShardBackendInfo}.
50 * @author Robert Varga
53 abstract class AbstractShardBackendResolver extends BackendInfoResolver<ShardBackendInfo> {
54 static final class ShardState {
55 private final CompletionStage<ShardBackendInfo> stage;
57 private ShardBackendInfo result;
59 ShardState(final CompletionStage<ShardBackendInfo> stage) {
60 this.stage = Preconditions.checkNotNull(stage);
61 stage.whenComplete(this::onStageResolved);
64 @Nonnull CompletionStage<ShardBackendInfo> getStage() {
68 @Nullable synchronized ShardBackendInfo getResult() {
72 private synchronized void onStageResolved(final ShardBackendInfo info, final Throwable failure) {
73 if (failure == null) {
74 this.result = Preconditions.checkNotNull(info);
76 LOG.warn("Failed to resolve shard", failure);
81 private static final Logger LOG = LoggerFactory.getLogger(AbstractShardBackendResolver.class);
84 * Connect request timeout. If the shard does not respond within this interval, we retry the lookup and connection.
86 // TODO: maybe make this configurable somehow?
87 private static final Timeout CONNECT_TIMEOUT = Timeout.apply(5, TimeUnit.SECONDS);
89 private final AtomicLong nextSessionId = new AtomicLong();
90 private final Function1<ActorRef, ?> connectFunction;
91 private final ActorContext actorContext;
92 private final Set<Consumer<Long>> staleBackendInfoCallbacks = ConcurrentHashMap.newKeySet();
94 // FIXME: we really need just ActorContext.findPrimaryShardAsync()
95 AbstractShardBackendResolver(final ClientIdentifier clientId, final ActorContext actorContext) {
96 this.actorContext = Preconditions.checkNotNull(actorContext);
97 this.connectFunction = ExplicitAsk.toScala(t -> new ConnectClientRequest(clientId, t, ABIVersion.BORON,
98 ABIVersion.current()));
102 public Registration notifyWhenBackendInfoIsStale(final Consumer<Long> callback) {
103 staleBackendInfoCallbacks.add(callback);
104 return () -> staleBackendInfoCallbacks.remove(callback);
107 protected void notifyStaleBackendInfoCallbacks(Long cookie) {
108 staleBackendInfoCallbacks.forEach(callback -> callback.accept(cookie));
111 protected ActorContext actorContext() {
115 protected final void flushCache(final String shardName) {
116 actorContext.getPrimaryShardInfoCache().remove(shardName);
119 protected final ShardState resolveBackendInfo(final String shardName, final long cookie) {
120 LOG.debug("Resolving cookie {} to shard {}", cookie, shardName);
122 final CompletableFuture<ShardBackendInfo> future = new CompletableFuture<>();
123 FutureConverters.toJava(actorContext.findPrimaryShardAsync(shardName)).whenComplete((info, failure) -> {
124 if (failure == null) {
125 connectShard(shardName, cookie, info, future);
129 LOG.debug("Shard {} failed to resolve", shardName, failure);
130 if (failure instanceof NoShardLeaderException) {
131 future.completeExceptionally(wrap("Shard has no current leader", failure));
132 } else if (failure instanceof NotInitializedException) {
133 // FIXME: this actually is an exception we can retry on
134 LOG.info("Shard {} has not initialized yet", shardName);
135 future.completeExceptionally(failure);
136 } else if (failure instanceof PrimaryNotFoundException) {
137 LOG.info("Failed to find primary for shard {}", shardName);
138 future.completeExceptionally(failure);
140 future.completeExceptionally(failure);
144 return new ShardState(future);
147 private static TimeoutException wrap(final String message, final Throwable cause) {
148 final TimeoutException ret = new TimeoutException(message);
149 ret.initCause(Preconditions.checkNotNull(cause));
153 private void connectShard(final String shardName, final long cookie, final PrimaryShardInfo info,
154 final CompletableFuture<ShardBackendInfo> future) {
155 LOG.debug("Shard {} resolved to {}, attempting to connect", shardName, info);
157 FutureConverters.toJava(ExplicitAsk.ask(info.getPrimaryShardActor(), connectFunction, CONNECT_TIMEOUT))
158 .whenComplete((response, failure) -> onConnectResponse(shardName, cookie, future, response, failure));
161 private void onConnectResponse(final String shardName, final long cookie,
162 final CompletableFuture<ShardBackendInfo> future, final Object response, final Throwable failure) {
163 if (failure != null) {
164 LOG.debug("Connect attempt to {} failed, will retry", shardName, failure);
165 future.completeExceptionally(wrap("Connection attempt failed", failure));
168 if (response instanceof RequestFailure) {
169 final Throwable cause = ((RequestFailure<?, ?>) response).getCause().unwrap();
170 LOG.debug("Connect attempt to {} failed to process", shardName, cause);
171 final Throwable result = cause instanceof NotLeaderException
172 ? wrap("Leader moved during establishment", cause) : cause;
173 future.completeExceptionally(result);
177 LOG.debug("Resolved backend information to {}", response);
178 Preconditions.checkArgument(response instanceof ConnectClientSuccess, "Unhandled response %s",
180 final ConnectClientSuccess success = (ConnectClientSuccess) response;
181 future.complete(new ShardBackendInfo(success.getBackend(), nextSessionId.getAndIncrement(),
182 success.getVersion(), shardName, UnsignedLong.fromLongBits(cookie), success.getDataTree(),
183 success.getMaxMessages()));