public abstract class AbstractClientConnection<T extends BackendInfo> {
private static final Logger LOG = LoggerFactory.getLogger(AbstractClientConnection.class);
- // Keep these constants in nanoseconds, as that prevents unnecessary conversions in the fast path
+ /*
+ * Timers involved in communication with the backend. There are three tiers which are spaced out to allow for
+ * recovery at each tier. Keep these constants in nanoseconds, as that prevents unnecessary conversions in the fast
+ * path.
+ */
+ /**
+ * 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
+ * it.
+ */
@VisibleForTesting
- static final long NO_PROGRESS_TIMEOUT_NANOS = TimeUnit.MINUTES.toNanos(15);
+ static final long 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.SECONDS.toNanos(30);
+ static final long REQUEST_TIMEOUT_NANOS = TimeUnit.MINUTES.toNanos(2);
- private static final FiniteDuration REQUEST_TIMEOUT_DURATION = FiniteDuration.apply(REQUEST_TIMEOUT_NANOS,
- TimeUnit.NANOSECONDS);
+ /**
+ * 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);
private final Lock lock = new ReentrantLock();
private final ClientActorContext context;
@GuardedBy("lock")
private boolean haveTimer;
+ /**
+ * Time reference when we saw any activity from the backend.
+ */
+ private long lastReceivedTicks;
+
private volatile RequestException poisoned;
// Do not allow subclassing outside of this package
this.context = Preconditions.checkNotNull(context);
this.cookie = Preconditions.checkNotNull(cookie);
this.queue = Preconditions.checkNotNull(queue);
+ this.lastReceivedTicks = currentTime();
}
// Do not allow subclassing outside of this package
this.context = oldConnection.context;
this.cookie = oldConnection.cookie;
this.queue = new TransmitQueue.Halted(targetQueueSize);
+ this.lastReceivedTicks = oldConnection.lastReceivedTicks;
}
public final ClientActorContext context() {
}
if (queue.isEmpty()) {
- // The queue is becoming non-empty, schedule a timer
- scheduleTimer(REQUEST_TIMEOUT_DURATION);
+ // The queue is becoming non-empty, schedule a timer.
+ scheduleTimer(entry.getEnqueuedTicks() + REQUEST_TIMEOUT_NANOS - now);
}
return queue.enqueue(entry, now);
} finally {
* @param delay Delay, in nanoseconds
*/
@GuardedBy("lock")
- private void scheduleTimer(final FiniteDuration delay) {
+ private void scheduleTimer(final long delay) {
if (haveTimer) {
LOG.debug("{}: timer already scheduled", context.persistenceId());
return;
LOG.debug("{}: connection has successor, not scheduling timer", context.persistenceId());
return;
}
- LOG.debug("{}: scheduling timeout in {}", context.persistenceId(), delay);
- context.executeInActor(this::runTimer, delay);
+
+ // 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 FiniteDuration dur = FiniteDuration.fromNanos(normalized);
+ LOG.debug("{}: scheduling timeout in {}", context.persistenceId(), dur);
+ context.executeInActor(this::runTimer, dur);
haveTimer = true;
}
*/
@VisibleForTesting
final ClientActorBehavior<T> runTimer(final ClientActorBehavior<T> current) {
- final Optional<FiniteDuration> delay;
+ final Optional<Long> delay;
lock.lock();
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,
}
@VisibleForTesting
- final Optional<FiniteDuration> checkTimeout(final long now) {
+ final Optional<Long> 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<FiniteDuration> lockedCheckTimeout(final long now) {
- final ConnectionEntry head = queue.peek();
- if (head == null) {
+ private Optional<Long> lockedCheckTimeout(final long now) {
+ if (queue.isEmpty()) {
return Optional.empty();
}
- final long beenOpen = now - head.getEnqueuedTicks();
- if (beenOpen >= REQUEST_TIMEOUT_NANOS) {
- LOG.debug("Connection {} has a request not completed for {} nanoseconds, timing out", this, beenOpen);
+ final long backendSilentTicks = now - lastReceivedTicks;
+ if (backendSilentTicks >= BACKEND_ALIVE_TIMEOUT_NANOS) {
+ LOG.debug("Connection {} has not seen activity from backend for {} nanoseconds, timing out", this,
+ backendSilentTicks);
return null;
}
- return Optional.of(FiniteDuration.apply(REQUEST_TIMEOUT_NANOS - beenOpen, TimeUnit.NANOSECONDS));
+ 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);
+ }
+
+ tasksTimedOut++;
+ queue.remove(now);
+ LOG.debug("Connection {} timed out entryt {}", this, head);
+ head.complete(head.getRequest().toRequestFailure(
+ new RequestTimeoutException("Timed out after " + beenOpen + "ns")));
+ }
+
+ LOG.debug("Connection {} timed out {} tasks", this, tasksTimedOut);
+ if (tasksTimedOut != 0) {
+ queue.tryTransmit(now);
+ }
+
+ return Optional.empty();
}
final void poison(final RequestException cause) {
final void receiveResponse(final ResponseEnvelope<?> envelope) {
final long now = currentTime();
+ lastReceivedTicks = now;
final Optional<TransmittedConnectionEntry> maybeEntry;
lock.lock();
Code Review / controller.git / blobdiff