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// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package ai.vespa.feed.client;
import ai.vespa.feed.client.FeedClient.CircuitBreaker;
import org.apache.hc.core5.http.ContentType;
import org.junit.jupiter.api.Test;
import java.io.IOException;
import java.net.URI;
import java.time.Duration;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.BiConsumer;
import static ai.vespa.feed.client.FeedClient.CircuitBreaker.State.CLOSED;
import static ai.vespa.feed.client.FeedClient.CircuitBreaker.State.HALF_OPEN;
import static ai.vespa.feed.client.FeedClient.CircuitBreaker.State.OPEN;
import static java.nio.charset.StandardCharsets.UTF_8;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
class HttpRequestStrategyTest {
@Test
void testConcurrency() {
int documents = 1 << 16;
HttpRequest request = new HttpRequest("PUT", "/", null, null);
HttpResponse response = HttpResponse.of(200, "{}".getBytes(UTF_8));
ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);
Cluster cluster = new BenchmarkingCluster((__, vessel) -> executor.schedule(() -> vessel.complete(response), (int) (Math.random() * 2 * 10), TimeUnit.MILLISECONDS));
HttpRequestStrategy strategy = new HttpRequestStrategy(FeedClientBuilder.create(URI.create("https://dummy.com:123"))
.setConnectionsPerEndpoint(1 << 10)
.setMaxStreamPerConnection(1 << 12),
cluster);
CountDownLatch latch = new CountDownLatch(1);
new Thread(() -> {
try {
while ( ! latch.await(1, TimeUnit.SECONDS)) {
System.err.println(cluster.stats().inflight());
System.err.println(strategy.throttler.targetInflight());
System.err.println();
}
}
catch (InterruptedException ignored) { }
}).start();
long startNanos = System.nanoTime();
for (int i = 0; i < documents; i++)
strategy.enqueue(DocumentId.of("ns", "type", Integer.toString(i)), request);
strategy.await();
latch.countDown();
executor.shutdown();
cluster.close();
OperationStats stats = cluster.stats();
long successes = stats.responsesByCode().get(200);
System.err.println(successes + " successes in " + (System.nanoTime() - startNanos) * 1e-9 + " seconds");
System.err.println(stats);
assertEquals(documents, stats.requests());
assertEquals(documents, stats.responses());
assertEquals(documents, stats.responsesByCode().get(200));
assertEquals(0, stats.inflight());
assertEquals(0, stats.exceptions());
assertEquals(0, stats.bytesSent());
assertEquals(2 * documents, stats.bytesReceived());
}
@Test
void testLogic() throws ExecutionException, InterruptedException {
int minStreams = 16; // Hard limit for minimum number of streams per connection.
MockCluster cluster = new MockCluster();
AtomicLong now = new AtomicLong(0);
CircuitBreaker breaker = new GracePeriodCircuitBreaker(now::get, Duration.ofSeconds(1), Duration.ofMinutes(10));
HttpRequestStrategy strategy = new HttpRequestStrategy(FeedClientBuilder.create(URI.create("https://dummy.com:123"))
.setRetryStrategy(new FeedClient.RetryStrategy() {
@Override public boolean retry(FeedClient.OperationType type) { return type == FeedClient.OperationType.PUT; }
@Override public int retries() { return 1; }
})
.setCircuitBreaker(breaker)
.setConnectionsPerEndpoint(1)
.setMaxStreamPerConnection(minStreams),
new BenchmarkingCluster(cluster));
DocumentId id1 = DocumentId.of("ns", "type", "1");
DocumentId id2 = DocumentId.of("ns", "type", "2");
HttpRequest request = new HttpRequest("POST", "/", null, null);
// Runtime exception is not retried.
cluster.expect((__, vessel) -> vessel.completeExceptionally(new FeedException("boom")));
ExecutionException expected = assertThrows(ExecutionException.class,
() -> strategy.enqueue(id1, request).get());
assertEquals("boom", expected.getCause().getMessage());
assertEquals(1, strategy.stats().requests());
// IOException is retried.
cluster.expect((__, vessel) -> vessel.completeExceptionally(new IOException("retry me")));
expected = assertThrows(ExecutionException.class,
() -> strategy.enqueue(id1, request).get());
assertEquals("retry me", expected.getCause().getCause().getMessage());
assertEquals(3, strategy.stats().requests());
// Successful response is returned
HttpResponse success = HttpResponse.of(200, null);
cluster.expect((__, vessel) -> vessel.complete(success));
assertEquals(success, strategy.enqueue(id1, request).get());
assertEquals(4, strategy.stats().requests());
// Throttled requests are retried. Concurrent operations to same ID (only) are serialised.
now.set(2000);
HttpResponse throttled = HttpResponse.of(429, null);
AtomicInteger count = new AtomicInteger(3);
CountDownLatch latch = new CountDownLatch(1);
AtomicReference<CompletableFuture<HttpResponse>> completion = new AtomicReference<>();
cluster.expect((req, vessel) -> {
if (req == request) {
if (count.decrementAndGet() > 0)
vessel.complete(throttled);
else {
completion.set(vessel);
latch.countDown();
}
}
else vessel.complete(success);
});
CompletableFuture<HttpResponse> delayed = strategy.enqueue(id1, request);
CompletableFuture<HttpResponse> serialised = strategy.enqueue(id1, new HttpRequest("PUT", "/", null, null));
assertEquals(success, strategy.enqueue(id2, new HttpRequest("DELETE", "/", null, null)).get());
latch.await();
assertEquals(8, strategy.stats().requests()); // 3 attempts at throttled and one at id2.
now.set(4000);
assertEquals(CLOSED, breaker.state()); // Circuit not broken due to throttled requests.
completion.get().complete(success);
assertEquals(success, delayed.get());
assertEquals(success, serialised.get());
// Some error responses are retried.
HttpResponse serverError = HttpResponse.of(500, null);
cluster.expect((__, vessel) -> vessel.complete(serverError));
assertEquals(serverError, strategy.enqueue(id1, request).get());
assertEquals(11, strategy.stats().requests());
assertEquals(CLOSED, breaker.state()); // Circuit not broken due to throttled requests.
// Error responses are not retried when not of appropriate type.
cluster.expect((__, vessel) -> vessel.complete(serverError));
assertEquals(serverError, strategy.enqueue(id1, new HttpRequest("PUT", "/", null, null)).get());
assertEquals(12, strategy.stats().requests());
// Some error responses are not retried.
HttpResponse badRequest = HttpResponse.of(400, null);
cluster.expect((__, vessel) -> vessel.complete(badRequest));
assertEquals(badRequest, strategy.enqueue(id1, request).get());
assertEquals(13, strategy.stats().requests());
// Circuit breaker opens some time after starting to fail.
now.set(6000);
assertEquals(HALF_OPEN, breaker.state()); // Circuit broken due to failed requests.
now.set(605000);
assertEquals(OPEN, breaker.state()); // Circuit broken due to failed requests.
Map<Integer, Long> codes = new HashMap<>();
codes.put(200, 4L);
codes.put(400, 1L);
codes.put(429, 2L);
codes.put(500, 3L);
assertEquals(codes, strategy.stats().responsesByCode());
assertEquals(3, strategy.stats().exceptions());
}
static class MockCluster implements Cluster {
final AtomicReference<BiConsumer<HttpRequest, CompletableFuture<HttpResponse>>> dispatch = new AtomicReference<>();
void expect(BiConsumer<HttpRequest, CompletableFuture<HttpResponse>> expected) {
dispatch.set(expected);
}
@Override
public void dispatch(HttpRequest request, CompletableFuture<HttpResponse> vessel) {
dispatch.get().accept(request, vessel);
}
@Override
public void close() { }
@Override
public OperationStats stats() {
return null;
}
}
}
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