TimeWindowStatisticsImplTest.java
/*
* Copyright (c) 2013, 2022 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.jersey.server.internal.monitoring;
import java.util.concurrent.TimeUnit;
import org.glassfish.jersey.server.internal.monitoring.core.ReservoirConstants;
import org.glassfish.jersey.server.internal.monitoring.core.UniformTimeReservoir;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
/**
* Tests of {@link TimeWindowStatisticsImpl}.
*
* @author Miroslav Fuksa
* @author Stepan Vavra
*/
public class TimeWindowStatisticsImplTest {
private static final int COLLISION_BUFFER_POWER = 3;
private static final double DELTA = 0.0001;
@Test
public void jvmLoaded() {
assertEquals(COLLISION_BUFFER_POWER, ReservoirConstants.COLLISION_BUFFER_POWER);
assertEquals(8, ReservoirConstants.COLLISION_BUFFER);
}
@Test
public void test() {
final long now = System.currentTimeMillis();
final TimeWindowStatisticsImpl.Builder<Long> builder = new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(1000L, TimeUnit.MILLISECONDS, now, TimeUnit.MILLISECONDS));
builder.addRequest(now, 30L);
builder.addRequest(now + 300, 100L);
builder.addRequest(now + 600, 150L);
builder.addRequest(now + 800, 15L);
builder.addRequest(now + 999, 60L);
builder.addRequest(now + 1000, 95L);
check(builder, now + 1000, 6, 15, 150, 75, 6);
builder.addRequest(now + 1001, 999L);
// the original implementation was supposed to trim the first request, we can only guess why it didn't ...
check(builder, now + 1001, 6, 15, 999, 236, 6);
}
@Test
public void test10() {
final long now = 0;
final TimeWindowStatisticsImpl.Builder<Long> builder
= new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(10000, TimeUnit.MILLISECONDS, now, TimeUnit.MILLISECONDS));
builder.addRequest(now, 30L);
builder.addRequest(now + 300, 100L);
builder.addRequest(now + 600, 150L);
builder.addRequest(now + 800, 15L);
builder.addRequest(now + 999, 60L);
builder.addRequest(now + 1000, 95L);
builder.addRequest(now + 8001, 600L);
// check unfinished interval
check(builder, now + 8001, 7, 15, 600, 150, 0.8748906);
// the original implementation used chunks for time units and the metrics calculation
// was accurate only when aligned with the chunks; now, we're accurate as possible which
// is why we don't need to use ratio (to adjust the count of the request in the last chunk
check(builder, now + 10900, 3, 60, 600, 251, 0.3);
// the original calculation left minimum as '15' which collides with the api doc
check(builder, now + 11000, 2, 95, 600, 347, 0.2);
}
/**
* This test shows that current implementation of {@link org.glassfish.jersey.server.monitoring.TimeWindowStatistics} is able
* to process information that happened before the last update time.
*/
@Test
public void testRequestInPast() {
final long now = 0;
final TimeWindowStatisticsImpl.Builder<Long> builder
= new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(1000, TimeUnit.MILLISECONDS, now, TimeUnit.MILLISECONDS));
builder.addRequest(now, 40L);
builder.addRequest(now + 1000, 30L);
// this is a request in past which will actually reuse the time 'now + 1000'
builder.addRequest(now + 100, 10L);
check(builder, now + 1000, 3, 10, 40, 26, 3);
// this request in past is so old that it doesn't even fit into the window
builder.addRequest(now + 100, 0L);
builder.addRequest(now + 1200, 20L);
check(builder, now + 1201, 2, 20, 30, 25, 2);
// snapshot retrieval in past does return values in past; in fact, time 'now + 1201' is used
check(builder, now + 1000, 2, 20, 30, 25, 2);
}
@Test
public void test3s() {
final long now = 0;
final TimeWindowStatisticsImpl.Builder<Long> builder
= new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(3000, TimeUnit.MILLISECONDS, now, TimeUnit.MILLISECONDS));
builder.addRequest(now, 99L);
builder.addRequest(now + 300, 98L);
builder.addRequest(now + 600, 1L);
builder.addRequest(now + 1000, 96L);
builder.addRequest(now + 1500, 95L);
builder.addRequest(now + 2500, 3L);
// ... above should be ignored
builder.addRequest(now + 3500, 90L);
builder.addRequest(now + 3900, 4L);
builder.addRequest(now + 3900, 80L);
builder.addRequest(now + 4200, 92L);
builder.addRequest(now + 4900, 15L);
builder.addRequest(now + 5300, 8L);
builder.addRequest(now + 5600, 50L);
check(builder, now + 6001, 7, 4, 92, 48, 2.333333);
}
@Test
public void testLongPause() {
final long now = 0;
final TimeWindowStatisticsImpl.Builder<Long> builder = new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(60, TimeUnit.SECONDS, now, TimeUnit.MILLISECONDS));
builder.addRequest(now, 99L);
final long time = now + 1000 * 60 * 60 * 23;
builder.addRequest(time, 95L);
builder.addRequest(time + 5, 5L);
check(builder, time + 20000, 2, 5, 95, 50, 0.03333);
}
@Test
public void testMultipleRequestsAtTheSameTime() {
final long now = 0;
final TimeWindowStatisticsImpl.Builder<Long> builder = new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(1, TimeUnit.SECONDS, now, TimeUnit.MILLISECONDS));
// put multiple requests at the beginning so that even the COLLISION_BUFFER bounds is tested
builder.addRequest(now, 10L);
builder.addRequest(now, 20L);
builder.addRequest(now, 30L);
builder.addRequest(now, 40L);
builder.addRequest(now + 1, 50L);
// put multiple requests in the middle of the window
builder.addRequest(now + 500, 60L);
builder.addRequest(now + 500, 70L);
check(builder, now + 500, 7, 10, 70, 40, 14);
// put multiple requests at the end of the window
builder.addRequest(now + 1000, 80L);
builder.addRequest(now + 1000, 90L);
check(builder, now + 1000, 9, 10, 90, 50, 9);
// at 'now + 1001' all the requests from 'now' should be gone
check(builder, now + 1001, 5, 50, 90, 70, 5);
}
@Test
public void testExhaustiveRequestsAtTheSameTime() {
final long now = 0;
final TimeWindowStatisticsImpl.Builder<Long> builder = new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(1, TimeUnit.SECONDS, now, TimeUnit.MILLISECONDS));
// put multiple requests at the beginning so that even the COLLISION_BUFFER bounds is tested
for (int i = 0; i < ReservoirConstants.COLLISION_BUFFER; ++i) {
builder.addRequest(now, 10L);
}
// add one more request which should be visible at 'now + 1001'
builder.addRequest(now + 1, 10L);
// put multiple requests in the middle of the window
for (int i = 0; i < ReservoirConstants.COLLISION_BUFFER; ++i) {
builder.addRequest(now + 500, 10L);
}
check(builder, now + 500, ReservoirConstants.COLLISION_BUFFER * 2 + 1, 10, 10, 10, ReservoirConstants.COLLISION_BUFFER * 2 * 2 + 1 * 2);
// put multiple requests at the end of the window
for (int i = 0; i < ReservoirConstants.COLLISION_BUFFER; ++i) {
builder.addRequest(now + 1000, 10L);
}
check(builder, now + 1000, ReservoirConstants.COLLISION_BUFFER * 3 + 1, 10, 10, 10, ReservoirConstants.COLLISION_BUFFER * 3 + 1);
// at 'now + 1001' all the requests from 'now' should be gone
check(builder, now + 1001, ReservoirConstants.COLLISION_BUFFER * 2 + 1, 10, 10, 10, ReservoirConstants.COLLISION_BUFFER * 2 + 1);
// at 'now + 1002' the one additional request we added is gone
check(builder, now + 1002, ReservoirConstants.COLLISION_BUFFER * 2, 10, 10, 10, ReservoirConstants.COLLISION_BUFFER * 2);
}
/**
* Tests JERSEY-2848
*/
@Test
public void testGapGreaterThanTimeWindowPause() {
final long now = 0;
final TimeWindowStatisticsImpl.Builder<Long> builder = new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(10, TimeUnit.SECONDS, now, TimeUnit.MILLISECONDS));
builder.addRequest(now, 91L);
builder.addRequest(now + 1000, 92L);
builder.addRequest(now + 2000, 93L);
// we need to add the time of last request + the whole time windows pause + additional time that is greater than unit time
// which is 1000
final long time = now + 2000 + 10000 + 1001;
// this request addition causes the queue to reset; however, the original implementation didn't reset the total count
// and total duration; as a result, the stats in that window became corrupted
builder.addRequest(time, 94L);
builder.addRequest(time + 1000, 95L);
builder.addRequest(time + 2000, 96L);
check(builder, time + 3000, 3, 94, 96, 95, 0.3);
// this line would pass before JERSEY-2848 was fixed; apparently, the values in this window became corrupted
// check(builder, time + 3000, 5, 94, 96, 93, 0.5);
}
private void check(final TimeWindowStatisticsImpl.Builder builder,
final long buildTime,
final int totalCount,
final int minimumExecTime,
final int maximumExecTime,
final long average,
final double requestsPerSecond) {
final TimeWindowStatisticsImpl stat = builder.build(buildTime);
assertEquals(totalCount, stat.getRequestCount(), "Total count does not match!");
assertEquals(minimumExecTime, stat.getMinimumDuration(), "Min exec time does not match!");
assertEquals(maximumExecTime, stat.getMaximumDuration(), "Max exec time does not match!");
assertEquals(average, stat.getAverageDuration(), "Average exec time does not match!");
assertEquals(requestsPerSecond, stat.getRequestsPerSecond(), DELTA, "Requests per seconds does not match!");
}
@Test
public void testGeneric() {
final TimeWindowStatisticsImpl.Builder<Long> builder = new TimeWindowStatisticsImpl.Builder<>(
new SlidingWindowTimeReservoir(10, TimeUnit.SECONDS, 0, TimeUnit.MILLISECONDS));
for (int i = 0; i < 100; i++) {
final int requestTime = i * 10000;
builder.addRequest(requestTime + 1, (long) i);
for (int j = 11; j < 100; j++) {
try {
final TimeWindowStatisticsImpl stat = builder.build(requestTime + j * 100);
assertEquals(1, stat.getRequestCount());
assertEquals(i, stat.getMinimumDuration());
assertEquals(i, stat.getMaximumDuration());
} catch (final AssertionError e) {
throw new AssertionError("i=" + i + ", j=" + j, e);
}
}
}
}
@Test
public void testUnlimited() {
final TimeWindowStatisticsImpl.Builder<Long> builder = new TimeWindowStatisticsImpl.Builder<>(
new UniformTimeReservoir(0, TimeUnit.MILLISECONDS));
check(builder, 0, 0, 0, 0, 0, 0);
check(builder, 10000, 0, 0, 0, 0, 0);
builder.addRequest(0, 10L);
check(builder, 50, 1, 10, 10, 10, 20.0);
builder.addRequest(100 + 300, 20L);
builder.addRequest(1000 + 600, 30L);
builder.addRequest(1587 + 800, 40L);
builder.addRequest(5544 + 999, 60L);
builder.addRequest(9998 + 1000, 50L);
check(builder, 10000, 6, 10, 60, 35, 0.6);
}
}