JKonSir commented on code in PR #7680: URL: https://github.com/apache/ignite-3/pull/7680#discussion_r3044301663
########## modules/core/src/test/java/org/apache/ignite/internal/util/retry/ExponentialBackoffTimeoutStrategyTest.java: ########## @@ -0,0 +1,113 @@ +/* + * 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.ignite.internal.util.retry; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertTrue; + +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +/** + * Unit tests for {@link ExponentialBackoffTimeoutStrategy}. + * + * <p>Verifies the correctness of exponential timeout progression, the maximum timeout + * ceiling, and optional jitter behavior. Tests use predictable integer arithmetic to + * make expected values easy to verify by hand. + */ +public class ExponentialBackoffTimeoutStrategyTest { + /** Initial timeout passed to {@link TimeoutStrategy#next(int)} as the starting value. */ + private static final int INITIAL_TIMEOUT = 20; + + /** Maximum timeout the strategy is allowed to produce. */ + private static final int MAX_TIMEOUT = 100; + + /** Backoff coefficient used by the default strategy instance. Doubles each timeout step. */ + private static final double BACKOFF_COEFFICIENT = 2.0; + + /** Strategy instance under test, recreated before each test. */ + private TimeoutStrategy timeoutStrategy; + + /** + * Creates a fresh {@link ExponentialBackoffTimeoutStrategy} with {@link #MAX_TIMEOUT} + * and {@link #BACKOFF_COEFFICIENT}, without jitter, before each test. + */ + @BeforeEach + void setUp() { + timeoutStrategy = new ExponentialBackoffTimeoutStrategy(MAX_TIMEOUT, BACKOFF_COEFFICIENT); + } + + /** + * Verifies that a single call to {@link TimeoutStrategy#next(int)} returns + * {@code currentTimeout * backoffCoefficient}. + * + * <p>This is the core contract of the exponential strategy — each step multiplies + * the current timeout by the configured coefficient. + */ + @Test + void testGettingNextTimeout() { + assertEquals(BACKOFF_COEFFICIENT * INITIAL_TIMEOUT, timeoutStrategy.next(INITIAL_TIMEOUT)); + } + + /** + * Verifies that the timeout progression reaches {@link #MAX_TIMEOUT} within the + * expected number of steps and does not exceed it on subsequent calls. + * + * <p>The upper bound on steps is computed from the coefficient and the ratio of + * {@code MAX_TIMEOUT} to {@code INITIAL_TIMEOUT}. If the strategy fails to reach + * the cap within this bound, the test fails with a descriptive message. Once the + * cap is reached, a further call to {@link TimeoutStrategy#next(int)} must return + * exactly {@link #MAX_TIMEOUT}. + */ + @Test + void testMaxTimeoutNotExceeded() { + int maxSteps = 3; + int steps = 0; + + int timeout = INITIAL_TIMEOUT; + do { + timeout = timeoutStrategy.next(timeout); + + assertTrue(++steps <= maxSteps, + "Strategy did not reach MAX_TIMEOUT within expected steps, last timeout: " + timeout); + } while (timeout < MAX_TIMEOUT); + + assertEquals(MAX_TIMEOUT, timeout); + assertEquals(MAX_TIMEOUT, timeoutStrategy.next(timeout)); + } + + /** + * Verifies that when jitter is enabled, the returned timeout falls within the + * expected randomized range {@code [initialTimeout, initialTimeout * coefficient^2)}. + * + * <p>A separate strategy instance with jitter enabled is created for this test. + * The lower bound confirms the jitter does not produce values below the initial + * timeout; the upper bound confirms it does not jump more than two coefficient + * steps in a single call. + */ + @Test + void testJitterApplying() { Review Comment: done -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
