*/
package org.opendaylight.controller.cluster.access.client;
+import static java.util.Objects.requireNonNull;
+
import akka.actor.ActorRef;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.MoreObjects;
import com.google.common.base.MoreObjects.ToStringHelper;
-import com.google.common.base.Preconditions;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.util.Collection;
+import java.util.List;
import java.util.Optional;
+import java.util.OptionalLong;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.function.Consumer;
-import javax.annotation.Nonnull;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.NotThreadSafe;
+import org.checkerframework.checker.lock.qual.GuardedBy;
+import org.checkerframework.checker.lock.qual.Holding;
+import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.controller.cluster.access.concepts.Request;
import org.opendaylight.controller.cluster.access.concepts.RequestException;
import org.opendaylight.controller.cluster.access.concepts.Response;
/**
* Base class for a connection to the backend. Responsible to queueing and dispatch of requests toward the backend.
* Can be in three conceptual states: Connecting, Connected and Reconnecting, which are represented by public final
- * classes exposed from this package.
+ * classes exposed from this package. This class NOT thread-safe, not are its subclasses expected to be thread-safe.
*
* @author Robert Varga
*/
-@NotThreadSafe
public abstract class AbstractClientConnection<T extends BackendInfo> {
private static final Logger LOG = LoggerFactory.getLogger(AbstractClientConnection.class);
*/
/**
* Backend aliveness timer. This is reset whenever we receive a response from the backend and kept armed whenever
- * we have an outstanding request. If when this time expires, we tear down this connection and attept to reconnect
+ * we have an outstanding request. If when this time expires, we tear down this connection and attempt to reconnect
* it.
*/
- @VisibleForTesting
- static final long BACKEND_ALIVE_TIMEOUT_NANOS = TimeUnit.SECONDS.toNanos(30);
+ public static final long DEFAULT_BACKEND_ALIVE_TIMEOUT_NANOS = TimeUnit.SECONDS.toNanos(30);
/**
* Request timeout. If the request fails to complete within this time since it was originally enqueued, we time
* the request out.
*/
- @VisibleForTesting
- static final long REQUEST_TIMEOUT_NANOS = TimeUnit.MINUTES.toNanos(2);
+ public static final long DEFAULT_REQUEST_TIMEOUT_NANOS = TimeUnit.MINUTES.toNanos(2);
/**
* No progress timeout. A client fails to make any forward progress in this time, it will terminate itself.
*/
- @VisibleForTesting
- static final long NO_PROGRESS_TIMEOUT_NANOS = TimeUnit.MINUTES.toNanos(15);
+ public static final long DEFAULT_NO_PROGRESS_TIMEOUT_NANOS = TimeUnit.MINUTES.toNanos(15);
// Emit a debug entry if we sleep for more that this amount
private static final long DEBUG_DELAY_NANOS = TimeUnit.MILLISECONDS.toNanos(100);
private static final long MAX_DELAY_NANOS = TimeUnit.SECONDS.toNanos(MAX_DELAY_SECONDS);
private final Lock lock = new ReentrantLock();
- private final ClientActorContext context;
+ private final @NonNull ClientActorContext context;
+ private final @NonNull Long cookie;
+ private final String backendName;
@GuardedBy("lock")
private final TransmitQueue queue;
- private final Long cookie;
@GuardedBy("lock")
private boolean haveTimer;
private volatile RequestException poisoned;
+ // Private constructor to avoid code duplication.
+ private AbstractClientConnection(final AbstractClientConnection<T> oldConn, final TransmitQueue newQueue,
+ final String backendName) {
+ context = oldConn.context;
+ cookie = oldConn.cookie;
+ this.backendName = requireNonNull(backendName);
+ queue = requireNonNull(newQueue);
+ // Will be updated in finishReplay if needed.
+ lastReceivedTicks = oldConn.lastReceivedTicks;
+ }
+
+ // This constructor is only to be called by ConnectingClientConnection constructor.
// Do not allow subclassing outside of this package
- AbstractClientConnection(final ClientActorContext context, final Long cookie,
- final TransmitQueue queue) {
- this.context = Preconditions.checkNotNull(context);
- this.cookie = Preconditions.checkNotNull(cookie);
- this.queue = Preconditions.checkNotNull(queue);
- this.lastReceivedTicks = currentTime();
+ AbstractClientConnection(final ClientActorContext context, final Long cookie, final String backendName,
+ final int queueDepth) {
+ this.context = requireNonNull(context);
+ this.cookie = requireNonNull(cookie);
+ this.backendName = requireNonNull(backendName);
+ queue = new TransmitQueue.Halted(queueDepth);
+ lastReceivedTicks = currentTime();
}
+ // This constructor is only to be called (indirectly) by ReconnectingClientConnection constructor.
// Do not allow subclassing outside of this package
- AbstractClientConnection(final AbstractClientConnection<T> oldConnection, final int targetQueueSize) {
- this.context = oldConnection.context;
- this.cookie = oldConnection.cookie;
- this.queue = new TransmitQueue.Halted(targetQueueSize);
- this.lastReceivedTicks = oldConnection.lastReceivedTicks;
+ AbstractClientConnection(final AbstractClientConnection<T> oldConn) {
+ this(oldConn, new TransmitQueue.Halted(oldConn.queue, oldConn.currentTime()), oldConn.backendName);
}
- public final ClientActorContext context() {
+ // This constructor is only to be called (indirectly) by ConnectedClientConnection constructor.
+ // Do not allow subclassing outside of this package
+ AbstractClientConnection(final AbstractClientConnection<T> oldConn, final T newBackend,
+ final int queueDepth) {
+ this(oldConn, new TransmitQueue.Transmitting(oldConn.queue, queueDepth, newBackend, oldConn.currentTime(),
+ requireNonNull(oldConn.context).messageSlicer()), newBackend.getName());
+ }
+
+ public final @NonNull ClientActorContext context() {
return context;
}
- public final @Nonnull Long cookie() {
+ public final @NonNull Long cookie() {
return cookie;
}
- public final ActorRef localActor() {
+ public final @NonNull ActorRef localActor() {
return context.self();
}
*
* <p>
* Note that unlike {@link #sendRequest(Request, Consumer)}, this method does not exert backpressure, hence it
- * should never be called from an application thread.
+ * should never be called from an application thread and serves mostly for moving requests between queues.
*
* @param request Request to send
* @param callback Callback to invoke
enqueueEntry(new ConnectionEntry(request, callback, enqueuedTicks), currentTime());
}
- public final long enqueueEntry(final ConnectionEntry entry, final long now) {
+ private long enqueueOrForward(final ConnectionEntry entry, final long now) {
lock.lock();
try {
- final RequestException maybePoison = poisoned;
- if (maybePoison != null) {
- throw new IllegalStateException("Connection " + this + " has been poisoned", maybePoison);
- }
+ commonEnqueue(entry, now);
+ return queue.enqueueOrForward(entry, now);
+ } finally {
+ lock.unlock();
+ }
+ }
- if (queue.isEmpty()) {
- // The queue is becoming non-empty, schedule a timer.
- scheduleTimer(entry.getEnqueuedTicks() + REQUEST_TIMEOUT_NANOS - now);
- }
- return queue.enqueue(entry, now);
+ /**
+ * Enqueue an entry, possibly also transmitting it.
+ */
+ public final void enqueueEntry(final ConnectionEntry entry, final long now) {
+ lock.lock();
+ try {
+ commonEnqueue(entry, now);
+ queue.enqueueOrReplay(entry, now);
} finally {
lock.unlock();
}
}
+ @Holding("lock")
+ private void commonEnqueue(final ConnectionEntry entry, final long now) {
+ final RequestException maybePoison = poisoned;
+ if (maybePoison != null) {
+ throw new IllegalStateException("Connection " + this + " has been poisoned", maybePoison);
+ }
+
+ if (queue.isEmpty()) {
+ // The queue is becoming non-empty, schedule a timer.
+ scheduleTimer(entry.getEnqueuedTicks() + context.config().getRequestTimeout() - now);
+ }
+ }
+
+ // To be called from ClientActorBehavior on ConnectedClientConnection after entries are replayed.
+ final void cancelDebt() {
+ queue.cancelDebt(currentTime());
+ }
+
public abstract Optional<T> getBackendInfo();
final Collection<ConnectionEntry> startReplay() {
return queue.drain();
}
- @GuardedBy("lock")
+ @Holding("lock")
final void finishReplay(final ReconnectForwarder forwarder) {
setForwarder(forwarder);
lock.unlock();
}
- @GuardedBy("lock")
+ @Holding("lock")
final void setForwarder(final ReconnectForwarder forwarder) {
queue.setForwarder(forwarder, currentTime());
}
- @GuardedBy("lock")
+ @Holding("lock")
abstract ClientActorBehavior<T> lockedReconnect(ClientActorBehavior<T> current,
RequestException runtimeRequestException);
final void sendEntry(final ConnectionEntry entry, final long now) {
- long delay = enqueueEntry(entry, now);
+ long delay = enqueueOrForward(entry, now);
try {
if (delay >= DEBUG_DELAY_NANOS) {
if (delay > MAX_DELAY_NANOS) {
TimeUnit.NANOSECONDS.sleep(delay);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
- LOG.debug("Interrupted after sleeping {}ns", e, currentTime() - now);
+ LOG.debug("Interrupted after sleeping {}ns", currentTime() - now, e);
}
}
*
* @param delay Delay, in nanoseconds
*/
- @GuardedBy("lock")
+ @Holding("lock")
private void scheduleTimer(final long delay) {
if (haveTimer) {
LOG.debug("{}: timer already scheduled on {}", context.persistenceId(), this);
// If the delay is negative, we need to schedule an action immediately. While the caller could have checked
// for that condition and take appropriate action, but this is more convenient and less error-prone.
- final long normalized = delay <= 0 ? 0 : Math.min(delay, BACKEND_ALIVE_TIMEOUT_NANOS);
+ final long normalized = delay <= 0 ? 0 : Math.min(delay, context.config().getBackendAlivenessTimerInterval());
final FiniteDuration dur = FiniteDuration.fromNanos(normalized);
LOG.debug("{}: connection {} scheduling timeout in {}", context.persistenceId(), this, dur);
/**
* Check this queue for timeout and initiate reconnection if that happened. If the queue has not made progress
- * in {@link #NO_PROGRESS_TIMEOUT_NANOS} nanoseconds, it will be aborted.
+ * in {@link #DEFAULT_NO_PROGRESS_TIMEOUT_NANOS} nanoseconds, it will be aborted.
*
* @param current Current behavior
* @return Next behavior to use
*/
@VisibleForTesting
final ClientActorBehavior<T> runTimer(final ClientActorBehavior<T> current) {
- final Optional<Long> delay;
-
lock.lock();
+
+ final List<ConnectionEntry> poisonEntries;
+ final NoProgressException poisonCause;
try {
haveTimer = false;
final long now = currentTime();
// The following line is only reliable when queue is not forwarding, but such state should not last long.
// FIXME: BUG-8422: this may not be accurate w.r.t. replayed entries
final long ticksSinceProgress = queue.ticksStalling(now);
- if (ticksSinceProgress >= NO_PROGRESS_TIMEOUT_NANOS) {
- LOG.error("Queue {} has not seen progress in {} seconds, failing all requests", this,
- TimeUnit.NANOSECONDS.toSeconds(ticksSinceProgress));
+ if (ticksSinceProgress < context.config().getNoProgressTimeout()) {
+ // Requests are always scheduled in sequence, hence checking for timeout is relatively straightforward.
+ // Note we use also inquire about the delay, so we can re-schedule if needed, hence the unusual
+ // tri-state return convention.
+ final OptionalLong delay = lockedCheckTimeout(now);
+ if (delay == null) {
+ // We have timed out. There is no point in scheduling a timer
+ LOG.debug("{}: connection {} timed out", context.persistenceId(), this);
+ return lockedReconnect(current, new RuntimeRequestException("Backend connection timed out",
+ new TimeoutException()));
+ }
- lockedPoison(new NoProgressException(ticksSinceProgress));
- current.removeConnection(this);
- return current;
- }
+ if (delay.isPresent()) {
+ // If there is new delay, schedule a timer
+ scheduleTimer(delay.orElseThrow());
+ } else {
+ LOG.debug("{}: not scheduling timeout on {}", context.persistenceId(), this);
+ }
- // Requests are always scheduled in sequence, hence checking for timeout is relatively straightforward.
- // Note we use also inquire about the delay, so we can re-schedule if needed, hence the unusual tri-state
- // return convention.
- delay = lockedCheckTimeout(now);
- if (delay == null) {
- // We have timed out. There is no point in scheduling a timer
- LOG.debug("{}: connection {} timed out", context.persistenceId(), this);
- return lockedReconnect(current, new RuntimeRequestException("Backend connection timed out",
- new TimeoutException()));
+ return current;
}
- if (delay.isPresent()) {
- // If there is new delay, schedule a timer
- scheduleTimer(delay.get());
- } else {
- LOG.debug("{}: not scheduling timeout on {}", context.persistenceId(), this);
- }
+ LOG.error("Queue {} has not seen progress in {} seconds, failing all requests", this,
+ TimeUnit.NANOSECONDS.toSeconds(ticksSinceProgress));
+ poisonCause = new NoProgressException(ticksSinceProgress);
+ poisonEntries = lockedPoison(poisonCause);
+ current.removeConnection(this);
} finally {
lock.unlock();
}
+ poison(poisonEntries, poisonCause);
return current;
}
@VisibleForTesting
- final Optional<Long> checkTimeout(final long now) {
+ final OptionalLong checkTimeout(final long now) {
lock.lock();
try {
return lockedCheckTimeout(now);
@SuppressFBWarnings(value = "NP_OPTIONAL_RETURN_NULL",
justification = "Returning null Optional is documented in the API contract.")
@GuardedBy("lock")
- private Optional<Long> lockedCheckTimeout(final long now) {
+ private OptionalLong lockedCheckTimeout(final long now) {
if (queue.isEmpty()) {
LOG.debug("{}: connection {} is empty", context.persistenceId(), this);
- return Optional.empty();
+ return OptionalLong.empty();
}
final long backendSilentTicks = backendSilentTicks(now);
- if (backendSilentTicks >= BACKEND_ALIVE_TIMEOUT_NANOS) {
+ if (backendSilentTicks >= context.config().getBackendAlivenessTimerInterval()) {
LOG.debug("{}: Connection {} has not seen activity from backend for {} nanoseconds, timing out",
context.persistenceId(), this, backendSilentTicks);
return null;
int tasksTimedOut = 0;
for (ConnectionEntry head = queue.peek(); head != null; head = queue.peek()) {
final long beenOpen = now - head.getEnqueuedTicks();
- if (beenOpen < REQUEST_TIMEOUT_NANOS) {
- return Optional.of(REQUEST_TIMEOUT_NANOS - beenOpen);
+ final long requestTimeout = context.config().getRequestTimeout();
+ if (beenOpen < requestTimeout) {
+ return OptionalLong.of(requestTimeout - beenOpen);
}
tasksTimedOut++;
queue.remove(now);
LOG.debug("{}: Connection {} timed out entry {}", context.persistenceId(), this, head);
- head.complete(head.getRequest().toRequestFailure(
- new RequestTimeoutException("Timed out after " + beenOpen + "ns")));
+
+ timeoutEntry(head, beenOpen);
}
LOG.debug("Connection {} timed out {} tasks", this, tasksTimedOut);
queue.tryTransmit(now);
}
- return Optional.empty();
+ return OptionalLong.empty();
+ }
+
+ private void timeoutEntry(final ConnectionEntry entry, final long beenOpen) {
+ // Timeouts needs to be re-scheduled on actor thread because we are holding the lock on the current queue,
+ // which may be the tail of a successor chain. This is a problem if the callback attempts to send a request
+ // because that will attempt to lock the chain from the start, potentially causing a deadlock if there is
+ // a concurrent attempt to transmit.
+ context.executeInActor(current -> {
+ final double time = beenOpen * 1.0 / 1_000_000_000;
+ entry.complete(entry.getRequest().toRequestFailure(
+ new RequestTimeoutException(entry.getRequest() + " timed out after " + time
+ + " seconds. The backend for " + backendName + " is not available.")));
+ return current;
+ });
}
final void poison(final RequestException cause) {
+ final List<ConnectionEntry> entries;
+
lock.lock();
try {
- lockedPoison(cause);
+ entries = lockedPoison(cause);
} finally {
lock.unlock();
}
+
+ poison(entries, cause);
}
- @GuardedBy("lock")
- private void lockedPoison(final RequestException cause) {
+ // Do not hold any locks while calling this
+ private static void poison(final Collection<? extends ConnectionEntry> entries, final RequestException cause) {
+ for (ConnectionEntry e : entries) {
+ final Request<?, ?> request = e.getRequest();
+ LOG.trace("Poisoning request {}", request, cause);
+ e.complete(request.toRequestFailure(cause));
+ }
+ }
+
+ @Holding("lock")
+ private List<ConnectionEntry> lockedPoison(final RequestException cause) {
poisoned = enrichPoison(cause);
- queue.poison(cause);
+ return queue.poison();
}
RequestException enrichPoison(final RequestException ex) {
return poisoned;
}
- final void receiveResponse(final ResponseEnvelope<?> envelope) {
+ void receiveResponse(final ResponseEnvelope<?> envelope) {
final long now = currentTime();
lastReceivedTicks = now;
}
if (maybeEntry.isPresent()) {
- final TransmittedConnectionEntry entry = maybeEntry.get();
+ final TransmittedConnectionEntry entry = maybeEntry.orElseThrow();
LOG.debug("Completing {} with {}", entry, envelope);
entry.complete(envelope.getMessage());
}
Code Review / controller.git / blobdiff