anujmodi2021 commented on code in PR #6703: URL: https://github.com/apache/hadoop/pull/6703#discussion_r1741499620
########## hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestIORateLimiter.java: ########## @@ -0,0 +1,213 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.hadoop.fs; + +import java.time.Duration; + +import org.assertj.core.api.Assertions; +import org.junit.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.hadoop.fs.impl.IORateLimiterSupport; +import org.apache.hadoop.test.AbstractHadoopTestBase; +import org.apache.hadoop.util.RateLimiting; +import org.apache.hadoop.util.RateLimitingFactory; + +import static org.apache.hadoop.fs.statistics.StoreStatisticNames.OP_DELETE; +import static org.apache.hadoop.fs.statistics.StoreStatisticNames.OP_DELETE_BULK; +import static org.apache.hadoop.fs.statistics.StoreStatisticNames.OP_DELETE_DIR; +import static org.apache.hadoop.test.LambdaTestUtils.intercept; + +/** + * Test IO rate limiting in {@link RateLimiting} and {@link IORateLimiter}. + * <p> + * This includes: illegal arguments, and what if more capacity + * is requested than is available. + */ +public class TestIORateLimiter extends AbstractHadoopTestBase { + + private static final Logger LOG = LoggerFactory.getLogger( + TestIORateLimiter.class); + + public static final Path ROOT = new Path("/"); + + @Test + public void testAcquireCapacity() { + final int size = 10; + final RateLimiting limiter = RateLimitingFactory.create(size); + // do a chain of requests + limiter.acquire(0); + limiter.acquire(1); + limiter.acquire(2); + + // now ask for more than is allowed. This MUST work. + final int excess = size * 2; + limiter.acquire(excess); + assertDelayed(limiter, excess); + } + + @Test + public void testNegativeCapacityRejected() throws Throwable { + final RateLimiting limiter = RateLimitingFactory.create(1); + intercept(IllegalArgumentException.class, () -> + limiter.acquire(-1)); + } + + @Test + public void testNegativeLimiterCapacityRejected() throws Throwable { + intercept(IllegalArgumentException.class, () -> + RateLimitingFactory.create(-1)); + } + + /** + * This is a key behavior: it is acceptable to ask for more capacity + * than the caller has, the initial request must be granted, + * but the followup request must be delayed until enough capacity + * has been restored. + */ + @Test + public void testAcquireExcessCapacity() { + + // create a small limiter + final int size = 10; + final RateLimiting limiter = RateLimitingFactory.create(size); + + // now ask for more than is allowed. This MUST work. + final int excess = size * 2; + // first attempt gets more capacity than arrives every second. + assertNotDelayed(limiter, excess); + // second attempt will block + assertDelayed(limiter, excess); + // third attempt will block + assertDelayed(limiter, size); + // as these are short-cut, no delays. + assertNotDelayed(limiter, 0); + } + + @Test + public void testIORateLimiterWithLimitedCapacity() { + final int size = 10; + final IORateLimiter limiter = IORateLimiterSupport.createIORateLimiter(size); + // this size will use more than can be allocated in a second. + final int excess = size * 2; + // first attempt gets more capacity than arrives every second. + assertNotDelayed(limiter, OP_DELETE_DIR, excess); + // second attempt will block + assertDelayed(limiter, OP_DELETE_BULK, excess); + // third attempt will block + assertDelayed(limiter, OP_DELETE, size); + // as zero capacity requests are short-cut, no delays, ever. + assertNotDelayed(limiter, "", 0); + } + + /** + * Verify the unlimited rate limiter really is unlimited. + */ + @Test + public void testIORateLimiterWithUnlimitedCapacity() { + final IORateLimiter limiter = IORateLimiterSupport.unlimited(); + // this size will use more than can be allocated in a second. + + assertNotDelayed(limiter, "1", 100_000); + assertNotDelayed(limiter, "2", 100_000); + } + + @Test + public void testUnlimitedRejectsNegativeCapacity() throws Exception { + intercept(IllegalArgumentException.class, () -> + IORateLimiterSupport.unlimited().acquireIOCapacity("", ROOT, ROOT, -1)); + } + + @Test + public void testUnlimitedRejectsNullOperation() throws Exception { + intercept(IllegalArgumentException.class, () -> + IORateLimiterSupport.unlimited().acquireIOCapacity(null, ROOT, null, 0)); + } + + @Test + public void testUnlimitedRejectsNullSource() throws Exception { + intercept(IllegalArgumentException.class, () -> + IORateLimiterSupport.unlimited().acquireIOCapacity("", null, null, 1)); + } + + /** + * Assert that a request for a given capacity is delayed. + * There's no assertion on the duration, only that it is greater than 0. + * @param limiter limiter + * @param capacity capacity + */ + private static void assertNotDelayed(final RateLimiting limiter, final int capacity) { + assertZeroDuration(capacity, limiter.acquire(capacity)); + } + + /** + * Assert that a request for a given capacity is delayed. + * There's no assertion on the duration, only that it is greater than 0. + * @param limiter limiter + * @param capacity capacity + */ + private static void assertDelayed(final RateLimiting limiter, final int capacity) { + assertNonZeroDuration(capacity, limiter.acquire(capacity)); + } + + /** + * Assert that a request for a given capacity is not delayed. + * @param limiter limiter + * @param op operation + * @param capacity capacity + */ + private static void assertNotDelayed(IORateLimiter limiter, String op, int capacity) { + assertZeroDuration(capacity, limiter.acquireIOCapacity(op, ROOT, null, capacity)); + } + + /** + * Assert that a request for a given capacity is delayed. + * There's no assertion on the duration, only that it is greater than 0. + * @param limiter limiter + * @param op operation + * @param capacity capacity + */ + private static void assertDelayed(IORateLimiter limiter, String op, int capacity) { + assertNonZeroDuration(capacity, limiter.acquireIOCapacity(op, ROOT, null, capacity)); + } + + /** + * Assert that duration was not zero. + * @param capacity capacity requested + * @param duration duration + */ + private static void assertNonZeroDuration(final int capacity, final Duration duration) { + LOG.info("Delay for {} capacity: {}", capacity, duration); + Assertions.assertThat(duration) + .describedAs("delay for %d capacity", capacity) + .isGreaterThan(Duration.ZERO); + } + + /** + * Assert that duration was zero. + * @param capacity capacity requested + * @param duration duration + */ + private static void assertZeroDuration(final int capacity, final Duration duration) { + Assertions.assertThat(duration) + .describedAs("delay for %d capacity", capacity) + .isEqualTo(Duration.ZERO); + } +} Review Comment: Nit: EOF warning. -- This is an automated message from the Apache Git Service. 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