*/
package org.opendaylight.controller.cluster.databroker.actors.dds;
-import com.google.common.base.Preconditions;
+import static akka.pattern.Patterns.ask;
+import static com.google.common.base.Verify.verifyNotNull;
+
+import akka.dispatch.ExecutionContexts;
+import akka.dispatch.OnComplete;
+import akka.util.Timeout;
import com.google.common.collect.BiMap;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.collect.ImmutableBiMap.Builder;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
+import java.util.concurrent.TimeUnit;
+import org.checkerframework.checker.lock.qual.GuardedBy;
import org.opendaylight.controller.cluster.access.client.BackendInfoResolver;
import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
+import org.opendaylight.controller.cluster.datastore.shardmanager.RegisterForShardAvailabilityChanges;
import org.opendaylight.controller.cluster.datastore.shardstrategy.DefaultShardStrategy;
-import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
+import org.opendaylight.controller.cluster.datastore.utils.ActorUtils;
+import org.opendaylight.yangtools.concepts.Registration;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
+import scala.concurrent.Future;
/**
* {@link BackendInfoResolver} implementation for static shard configuration based on ShardManager. Each string-named
* shard is assigned a single cookie and this mapping is stored in a bidirectional map. Information about corresponding
- * shard leader is resolved via {@link ActorContext}. The product of resolution is {@link ShardBackendInfo}.
+ * shard leader is resolved via {@link ActorUtils}. The product of resolution is {@link ShardBackendInfo}.
+ *
+ * <p>
+ * This class is thread-safe.
*
* @author Robert Varga
*/
-@ThreadSafe
final class ModuleShardBackendResolver extends AbstractShardBackendResolver {
private static final Logger LOG = LoggerFactory.getLogger(ModuleShardBackendResolver.class);
private final ConcurrentMap<Long, ShardState> backends = new ConcurrentHashMap<>();
- private final ActorContext actorContext;
+
+ private final Future<Registration> shardAvailabilityChangesRegFuture;
@GuardedBy("this")
private long nextShard = 1;
private volatile BiMap<String, Long> shards = ImmutableBiMap.of(DefaultShardStrategy.DEFAULT_SHARD, 0L);
// FIXME: we really need just ActorContext.findPrimaryShardAsync()
- ModuleShardBackendResolver(final ClientIdentifier clientId, final ActorContext actorContext) {
- super(clientId, actorContext);
- this.actorContext = Preconditions.checkNotNull(actorContext);
+ ModuleShardBackendResolver(final ClientIdentifier clientId, final ActorUtils actorUtils) {
+ super(clientId, actorUtils);
+
+ shardAvailabilityChangesRegFuture = ask(actorUtils.getShardManager(), new RegisterForShardAvailabilityChanges(
+ this::onShardAvailabilityChange), Timeout.apply(60, TimeUnit.MINUTES))
+ .map(reply -> (Registration)reply, ExecutionContexts.global());
+
+ shardAvailabilityChangesRegFuture.onComplete(new OnComplete<Registration>() {
+ @Override
+ public void onComplete(Throwable failure, Registration reply) {
+ if (failure != null) {
+ LOG.error("RegisterForShardAvailabilityChanges failed", failure);
+ }
+ }
+ }, ExecutionContexts.global());
+ }
+
+ private void onShardAvailabilityChange(String shardName) {
+ LOG.debug("onShardAvailabilityChange for {}", shardName);
+
+ Long cookie = shards.get(shardName);
+ if (cookie == null) {
+ LOG.debug("No shard cookie found for {}", shardName);
+ return;
+ }
+
+ notifyStaleBackendInfoCallbacks(cookie);
}
Long resolveShardForPath(final YangInstanceIdentifier path) {
- final String shardName = actorContext.getShardStrategyFactory().getStrategy(path).findShard(path);
+ final String shardName = actorUtils().getShardStrategyFactory().getStrategy(path).findShard(path);
Long cookie = shards.get(shardName);
if (cookie == null) {
synchronized (this) {
return cookie;
}
- private ShardState resolveBackendInfo(final Long cookie) {
+ @Override
+ public CompletionStage<ShardBackendInfo> getBackendInfo(final Long cookie) {
+ /*
+ * We cannot perform a simple computeIfAbsent() here because we need to control sequencing of when the state
+ * is inserted into the map and retired from it (based on the stage result).
+ *
+ * We do not want to hook another stage one processing completes and hooking a removal on failure from a compute
+ * method runs the inherent risk of stage completing before the insertion does (i.e. we have a removal of
+ * non-existent element.
+ */
+ final ShardState existing = backends.get(cookie);
+ if (existing != null) {
+ return existing.getStage();
+ }
+
final String shardName = shards.inverse().get(cookie);
if (shardName == null) {
LOG.warn("Failing request for non-existent cookie {}", cookie);
- return null;
+ throw new IllegalArgumentException("Cookie " + cookie + " does not have a shard assigned");
}
LOG.debug("Resolving cookie {} to shard {}", cookie, shardName);
+ final ShardState toInsert = resolveBackendInfo(shardName, cookie);
- return resolveBackendInfo(shardName, cookie);
- }
+ final ShardState raced = backends.putIfAbsent(cookie, toInsert);
+ if (raced != null) {
+ // We have had a concurrent insertion, return that
+ LOG.debug("Race during insertion of state for cookie {} shard {}", cookie, shardName);
+ return raced.getStage();
+ }
- @Override
- public CompletionStage<ShardBackendInfo> getBackendInfo(final Long cookie) {
- return backends.computeIfAbsent(cookie, this::resolveBackendInfo).getStage();
+ // We have succeeded in populating the map, now we need to take care of pruning the entry if it fails to
+ // complete
+ final CompletionStage<ShardBackendInfo> stage = toInsert.getStage();
+ stage.whenComplete((info, failure) -> {
+ if (failure != null) {
+ LOG.debug("Resolution of cookie {} shard {} failed, removing state", cookie, shardName, failure);
+ backends.remove(cookie, toInsert);
+
+ // Remove cache state in case someone else forgot to invalidate it
+ flushCache(shardName);
+ }
+ });
+
+ return stage;
}
@Override
}
LOG.debug("Invalidating backend information {}", staleInfo);
- flushCache(staleInfo.getShardName());
+ flushCache(staleInfo.getName());
- LOG.trace("Invalidated cache %s", staleInfo);
+ LOG.trace("Invalidated cache {}", staleInfo);
backends.remove(cookie, existing);
}
return getBackendInfo(cookie);
}
+
+ @Override
+ public void close() {
+ shardAvailabilityChangesRegFuture.onComplete(new OnComplete<Registration>() {
+ @Override
+ public void onComplete(Throwable failure, Registration reply) {
+ reply.close();
+ }
+ }, ExecutionContexts.global());
+ }
+
+ @Override
+ public String resolveCookieName(Long cookie) {
+ return verifyNotNull(shards.inverse().get(cookie), "Unexpected null cookie: %s", cookie);
+ }
}