diff options
Diffstat (limited to 'vespa-feed-client/src/main/java/ai/vespa/feed/client/HttpRequestStrategy.java')
| -rw-r--r-- | vespa-feed-client/src/main/java/ai/vespa/feed/client/HttpRequestStrategy.java | 86 |
1 files changed, 55 insertions, 31 deletions
diff --git a/vespa-feed-client/src/main/java/ai/vespa/feed/client/HttpRequestStrategy.java b/vespa-feed-client/src/main/java/ai/vespa/feed/client/HttpRequestStrategy.java index 71de6ff2065..dc01f01b2e8 100644 --- a/vespa-feed-client/src/main/java/ai/vespa/feed/client/HttpRequestStrategy.java +++ b/vespa-feed-client/src/main/java/ai/vespa/feed/client/HttpRequestStrategy.java @@ -16,6 +16,7 @@ import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.atomic.AtomicBoolean; import java.util.concurrent.atomic.AtomicLong; +import java.util.concurrent.atomic.AtomicReference; import java.util.logging.Level; import java.util.logging.Logger; @@ -26,17 +27,13 @@ import static java.nio.charset.StandardCharsets.UTF_8; import static java.util.logging.Level.FINE; import static java.util.logging.Level.FINER; import static java.util.logging.Level.FINEST; -import static java.util.logging.Level.INFO; import static java.util.logging.Level.WARNING; -// TODO: update doc /** - * Controls request execution and retries: - * <ul> - * <li>Whenever throttled (429, 503), set target inflight to 0.9 * current, and retry over a different connection;</li> - * <li>retry other transient errors (500, 502 and IOException) a specified number of times, for specified operation types;</li> - * <li>and on every successful response, increase target inflight by 0.1.</li> - * </ul> + * Controls request execution and retries. + * + * This class has all control flow for throttling and dispatching HTTP requests to an injected + * HTTP cluster, including error handling and retries, and a circuit breaker mechanism. * * @author jonmv */ @@ -45,10 +42,10 @@ class HttpRequestStrategy implements RequestStrategy { private static final Logger log = Logger.getLogger(HttpRequestStrategy.class.getName()); private final Cluster cluster; - private final Map<DocumentId, CompletableFuture<?>> inflightById = new ConcurrentHashMap<>(); + private final Map<DocumentId, RetriableFuture<HttpResponse>> inflightById = new ConcurrentHashMap<>(); private final RetryStrategy strategy; private final CircuitBreaker breaker; - final FeedClient.Throttler throttler; + private final FeedClient.Throttler throttler; private final Queue<Runnable> queue = new ConcurrentLinkedQueue<>(); private final AtomicLong inflight = new AtomicLong(0); private final AtomicBoolean destroyed = new AtomicBoolean(false); @@ -89,21 +86,49 @@ class HttpRequestStrategy implements RequestStrategy { while (breaker.state() != OPEN && ! destroyed.get()) { while ( ! isInExcess() && poll() && breaker.state() == CLOSED); // Sleep when circuit is half-open, nap when queue is empty, or we are throttled. - Thread.sleep(breaker.state() == HALF_OPEN ? 1000 : 10); // TODO: Reduce throughput when turning half-open? + Thread.sleep(breaker.state() == HALF_OPEN ? 1000 : 10); } } - catch (InterruptedException e) { - Thread.currentThread().interrupt(); - log.log(WARNING, "Dispatch thread interrupted; shutting down"); + catch (Throwable t) { + log.log(WARNING, "Dispatch thread threw; shutting down", t); } destroy(); } private void offer(HttpRequest request, CompletableFuture<HttpResponse> vessel) { delayedCount.incrementAndGet(); - queue.offer(() -> { - cluster.dispatch(request, vessel); - }); + queue.offer(() -> cluster.dispatch(request, vessel)); + } + + + /** A completable future which stores a temporary failure result to return upon abortion. */ + private static class RetriableFuture<T> extends CompletableFuture<T> { + + private final AtomicReference<Runnable> completion = new AtomicReference<>(); + private final AtomicReference<RetriableFuture<T>> dependency = new AtomicReference<>(); + + private RetriableFuture() { + completion.set(() -> completeExceptionally(new FeedException("Operation aborted"))); + } + + /** Complete now with the last result or error. */ + void complete() { + completion.get().run(); + if (dependency.get() != null) dependency.getAndSet(null).complete(); + } + + /** Ensures the dependency is completed whenever this is. */ + void dependOn(RetriableFuture<T> dependency) { + this.dependency.set(dependency); + if (isDone()) dependency.complete(); + } + + /** Set the result of the last attempt at completing the computation represented by this. */ + void set(T result, Throwable thrown) { + completion.set(thrown != null ? () -> completeExceptionally(thrown) + : () -> complete(result)); + } + } private boolean poll() { @@ -208,11 +233,11 @@ class HttpRequestStrategy implements RequestStrategy { @Override public CompletableFuture<HttpResponse> enqueue(DocumentId documentId, HttpRequest request) { - CompletableFuture<HttpResponse> result = new CompletableFuture<>(); // Carries the aggregate result of the operation, including retries. + RetriableFuture<HttpResponse> result = new RetriableFuture<>(); // Carries the aggregate result of the operation, including retries. CompletableFuture<HttpResponse> vessel = new CompletableFuture<>(); // Holds the computation of a single dispatch to the HTTP client. - CompletableFuture<?> previous = inflightById.put(documentId, result); + RetriableFuture<HttpResponse> previous = inflightById.put(documentId, result); if (destroyed.get()) { - result.cancel(true); + result.complete(); return result; } @@ -221,13 +246,15 @@ class HttpRequestStrategy implements RequestStrategy { offer(request, vessel); throttler.sent(inflight.get(), result); } - else + else { + result.dependOn(previous); // In case result is aborted, also abort the previous if still inflight. previous.whenComplete((__, ___) -> offer(request, vessel)); + } handleAttempt(vessel, request, result, 1); return result.handle((response, error) -> { - if (inflightById.compute(documentId, (____, current) -> current == result ? null : current) == null) + if (inflightById.compute(documentId, (__, current) -> current == result ? null : current) == null) releaseSlot(); if (error != null) { @@ -239,29 +266,26 @@ class HttpRequestStrategy implements RequestStrategy { } /** Handles the result of one attempt at the given operation, retrying if necessary. */ - private void handleAttempt(CompletableFuture<HttpResponse> vessel, HttpRequest request, CompletableFuture<HttpResponse> result, int attempt) { + private void handleAttempt(CompletableFuture<HttpResponse> vessel, HttpRequest request, RetriableFuture<HttpResponse> result, int attempt) { vessel.whenCompleteAsync((response, thrown) -> { + result.set(response, thrown); // Retry the operation if it failed with a transient error ... if (thrown != null ? retry(request, thrown, attempt) : retry(request, response, attempt)) { - CircuitBreaker.State state = breaker.state(); CompletableFuture<HttpResponse> retry = new CompletableFuture<>(); offer(request, retry); - handleAttempt(retry, request, result, attempt + (state == HALF_OPEN ? 0 : 1)); + handleAttempt(retry, request, result, attempt + (breaker.state() == HALF_OPEN ? 0 : 1)); } // ... or accept the outcome and mark the operation as complete. - else { - if (thrown == null) result.complete(response); - else result.completeExceptionally(thrown); - } + else result.complete(); }, resultExecutor); } @Override public void destroy() { - if ( ! destroyed.getAndSet(true)) { - inflightById.values().forEach(result -> result.cancel(true)); // TODO: More informative exception. + if (destroyed.compareAndSet(false, true)) { + inflightById.values().forEach(RetriableFuture::complete); cluster.close(); resultExecutor.shutdown(); } |