BUG-8452: make NoShardLeaderException retriable
[controller.git] / opendaylight / md-sal / cds-access-client / src / main / java / org / opendaylight / controller / cluster / access / client / ClientActorBehavior.java
index 45580e92fd734489616c4840a5feac2f529aafd8..9ba118ed6b9c95a1d5c914a4b681413af4cce95d 100644 (file)
@@ -10,11 +10,16 @@ package org.opendaylight.controller.cluster.access.client;
 import com.google.common.annotations.Beta;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Verify;
+import java.util.Collection;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.GuardedBy;
+import org.opendaylight.controller.cluster.access.commands.NotLeaderException;
+import org.opendaylight.controller.cluster.access.commands.OutOfSequenceEnvelopeException;
 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
 import org.opendaylight.controller.cluster.access.concepts.FailureEnvelope;
 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
@@ -29,6 +34,7 @@ import org.opendaylight.yangtools.concepts.Identifiable;
 import org.opendaylight.yangtools.concepts.WritableIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import scala.concurrent.duration.FiniteDuration;
 
 /**
  * A behavior, which handles messages sent to a {@link AbstractClientActor}.
@@ -49,10 +55,11 @@ public abstract class ClientActorBehavior<T extends BackendInfo> extends
          * @param enqueuedEntries Previously-enqueued entries
          * @return A {@link ReconnectForwarder} to handle any straggler messages which arrive after this method returns.
          */
-        @Nonnull ReconnectForwarder finishReconnect(@Nonnull Iterable<ConnectionEntry> enqueuedEntries);
+        @Nonnull ReconnectForwarder finishReconnect(@Nonnull Collection<ConnectionEntry> enqueuedEntries);
     }
 
     private static final Logger LOG = LoggerFactory.getLogger(ClientActorBehavior.class);
+    private static final FiniteDuration RESOLVE_RETRY_DURATION = FiniteDuration.apply(5, TimeUnit.SECONDS);
 
     /**
      * Map of connections to the backend. This map is concurrent to allow lookups, but given complex operations
@@ -101,6 +108,11 @@ public abstract class ClientActorBehavior<T extends BackendInfo> extends
         }
     }
 
+    private AbstractClientConnection<T> getConnection(final ResponseEnvelope<?> response) {
+        // Always called from actor context: no locking required
+        return connections.get(extractCookie(response.getMessage().getTarget()));
+    }
+
     @SuppressWarnings("unchecked")
     @Override
     final ClientActorBehavior<T> onReceiveCommand(final Object command) {
@@ -128,8 +140,7 @@ public abstract class ClientActorBehavior<T extends BackendInfo> extends
     }
 
     private void onResponse(final ResponseEnvelope<?> response) {
-        final long cookie = extractCookie(response.getMessage().getTarget());
-        final AbstractClientConnection<T> connection = connections.get(cookie);
+        final AbstractClientConnection<T> connection = getConnection(response);
         if (connection != null) {
             connection.receiveResponse(response);
         } else {
@@ -156,6 +167,27 @@ public abstract class ClientActorBehavior<T extends BackendInfo> extends
             poison(cause);
             return null;
         }
+        if (cause instanceof NotLeaderException) {
+            final AbstractClientConnection<T> conn = getConnection(command);
+            if (conn instanceof ReconnectingClientConnection) {
+                // Already reconnecting, do not churn the logs
+                return this;
+            } else if (conn != null) {
+                LOG.info("{}: connection {} indicated no leadership, reconnecting it", persistenceId(), conn, cause);
+                return conn.reconnect(this, cause);
+            }
+        }
+        if (cause instanceof OutOfSequenceEnvelopeException) {
+            final AbstractClientConnection<T> conn = getConnection(command);
+            if (conn instanceof ReconnectingClientConnection) {
+                // Already reconnecting, do not churn the logs
+                return this;
+            } else if (conn != null) {
+                LOG.info("{}: connection {} indicated no sequencing mismatch on {} sequence {}, reconnecting it",
+                    persistenceId(), conn, failure.getTarget(), failure.getSequence(), cause);
+                return conn.reconnect(this, cause);
+            }
+        }
 
         return onRequestFailure(command);
     }
@@ -213,24 +245,49 @@ public abstract class ClientActorBehavior<T extends BackendInfo> extends
     private void backendConnectFinished(final Long shard, final AbstractClientConnection<T> conn,
             final T backend, final Throwable failure) {
         if (failure != null) {
+            if (failure instanceof TimeoutException) {
+                if (!conn.equals(connections.get(shard))) {
+                    // AbstractClientConnection will remove itself when it decides there is no point in continuing,
+                    // at which point we want to stop retrying
+                    LOG.info("{}: stopping resolution of shard {} on stale connection {}", persistenceId(), shard, conn,
+                        failure);
+                    return;
+                }
+
+                LOG.debug("{}: timed out resolving shard {}, scheduling retry in {}", persistenceId(), shard,
+                    RESOLVE_RETRY_DURATION, failure);
+                context().executeInActor(b -> {
+                    resolveConnection(shard, conn);
+                    return b;
+                }, RESOLVE_RETRY_DURATION);
+                return;
+            }
+
             LOG.error("{}: failed to resolve shard {}", persistenceId(), shard, failure);
-            conn.poison(new RuntimeRequestException("Failed to resolve shard " + shard, failure));
+            final RequestException cause;
+            if (failure instanceof RequestException) {
+                cause = (RequestException) failure;
+            } else {
+                cause = new RuntimeRequestException("Failed to resolve shard " + shard, failure);
+            }
+
+            conn.poison(cause);
             return;
         }
 
-        LOG.debug("{}: resolved shard {} to {}", persistenceId(), shard, backend);
+        LOG.info("{}: resolved shard {} to {}", persistenceId(), shard, backend);
         final long stamp = connectionsLock.writeLock();
         try {
             // Create a new connected connection
             final ConnectedClientConnection<T> newConn = new ConnectedClientConnection<>(conn.context(),
                     conn.cookie(), backend);
-            LOG.debug("{}: resolving connection {} to {}", persistenceId(), conn, newConn);
+            LOG.info("{}: resolving connection {} to {}", persistenceId(), conn, newConn);
 
             // Start reconnecting without the old connection lock held
             final ConnectionConnectCohort cohort = Verify.verifyNotNull(connectionUp(newConn));
 
             // Lock the old connection and get a reference to its entries
-            final Iterable<ConnectionEntry> replayIterable = conn.startReplay();
+            final Collection<ConnectionEntry> replayIterable = conn.startReplay();
 
             // Finish the connection attempt
             final ReconnectForwarder forwarder = Verify.verifyNotNull(cohort.finishReconnect(replayIterable));
@@ -239,26 +296,61 @@ public abstract class ClientActorBehavior<T extends BackendInfo> extends
             conn.finishReplay(forwarder);
 
             // Make sure new lookups pick up the new connection
-            connections.replace(shard, conn, newConn);
-            LOG.debug("{}: replaced connection {} with {}", persistenceId(), conn, newConn);
+            if (!connections.replace(shard, conn, newConn)) {
+                final AbstractClientConnection<T> existing = connections.get(conn.cookie());
+                LOG.warn("{}: old connection {} does not match existing {}, new connection {} in limbo",
+                    persistenceId(), conn, existing, newConn);
+            } else {
+                LOG.info("{}: replaced connection {} with {}", persistenceId(), conn, newConn);
+            }
         } finally {
             connectionsLock.unlockWrite(stamp);
         }
     }
 
     void removeConnection(final AbstractClientConnection<?> conn) {
-        connections.remove(conn.cookie(), conn);
-        LOG.debug("{}: removed connection {}", persistenceId(), conn);
+        final long stamp = connectionsLock.writeLock();
+        try {
+            if (!connections.remove(conn.cookie(), conn)) {
+                final AbstractClientConnection<T> existing = connections.get(conn.cookie());
+                if (existing != null) {
+                    LOG.warn("{}: failed to remove connection {}, as it was superseded by {}", persistenceId(), conn,
+                        existing);
+                } else {
+                    LOG.warn("{}: failed to remove connection {}, as it was not tracked", persistenceId(), conn);
+                }
+            } else {
+                LOG.info("{}: removed connection {}", persistenceId(), conn);
+            }
+        } finally {
+            connectionsLock.unlockWrite(stamp);
+        }
     }
 
     @SuppressWarnings("unchecked")
     void reconnectConnection(final ConnectedClientConnection<?> oldConn,
             final ReconnectingClientConnection<?> newConn) {
         final ReconnectingClientConnection<T> conn = (ReconnectingClientConnection<T>)newConn;
-        connections.replace(oldConn.cookie(), (AbstractClientConnection<T>)oldConn, conn);
-        LOG.debug("{}: connection {} reconnecting as {}", persistenceId(), oldConn, newConn);
+        LOG.info("{}: connection {} reconnecting as {}", persistenceId(), oldConn, newConn);
+
+        final long stamp = connectionsLock.writeLock();
+        try {
+            final boolean replaced = connections.replace(oldConn.cookie(), (AbstractClientConnection<T>)oldConn, conn);
+            if (!replaced) {
+                final AbstractClientConnection<T> existing = connections.get(oldConn.cookie());
+                if (existing != null) {
+                    LOG.warn("{}: failed to replace connection {}, as it was superseded by {}", persistenceId(), conn,
+                        existing);
+                } else {
+                    LOG.warn("{}: failed to replace connection {}, as it was not tracked", persistenceId(), conn);
+                }
+            }
+        } finally {
+            connectionsLock.unlockWrite(stamp);
+        }
 
         final Long shard = oldConn.cookie();
+        LOG.info("{}: refreshing backend for shard {}", persistenceId(), shard);
         resolver().refreshBackendInfo(shard, conn.getBackendInfo().get()).whenComplete(
             (backend, failure) -> context().executeInActor(behavior -> {
                 backendConnectFinished(shard, conn, backend, failure);
@@ -268,12 +360,15 @@ public abstract class ClientActorBehavior<T extends BackendInfo> extends
 
     private ConnectingClientConnection<T> createConnection(final Long shard) {
         final ConnectingClientConnection<T> conn = new ConnectingClientConnection<>(context(), shard);
+        resolveConnection(shard, conn);
+        return conn;
+    }
 
+    private void resolveConnection(final Long shard, final AbstractClientConnection<T> conn) {
+        LOG.debug("{}: resolving shard {} connection {}", persistenceId(), shard, conn);
         resolver().getBackendInfo(shard).whenComplete((backend, failure) -> context().executeInActor(behavior -> {
             backendConnectFinished(shard, conn, backend, failure);
             return behavior;
         }));
-
-        return conn;
     }
 }