001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.replication.regionserver;
019
020import static org.junit.jupiter.api.Assertions.assertEquals;
021import static org.junit.jupiter.api.Assertions.assertTrue;
022
023import org.apache.hadoop.hbase.testclassification.ReplicationTests;
024import org.apache.hadoop.hbase.testclassification.SmallTests;
025import org.junit.jupiter.api.Tag;
026import org.junit.jupiter.api.Test;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030@Tag(ReplicationTests.TAG)
031@Tag(SmallTests.TAG)
032public class TestReplicationThrottler {
033
034  private static final Logger LOG = LoggerFactory.getLogger(TestReplicationThrottler.class);
035
036  /**
037   * unit test for throttling
038   */
039  @Test
040  public void testThrottling() {
041    LOG.info("testThrottling");
042
043    // throttle bandwidth is 100 and 10 bytes/cycle respectively
044    ReplicationThrottler throttler1 = new ReplicationThrottler(100);
045    ReplicationThrottler throttler2 = new ReplicationThrottler(10);
046
047    long ticks1 = throttler1.getNextSleepInterval(1000);
048    long ticks2 = throttler2.getNextSleepInterval(1000);
049
050    // 1. the first push size is 1000, though 1000 bytes exceeds 100/10
051    // bandwidthes, but no sleep since it's the first push of current
052    // cycle, amortizing occurs when next push arrives
053    assertEquals(0, ticks1);
054    assertEquals(0, ticks2);
055
056    throttler1.addPushSize(1000);
057    throttler2.addPushSize(1000);
058
059    ticks1 = throttler1.getNextSleepInterval(5);
060    ticks2 = throttler2.getNextSleepInterval(5);
061
062    // 2. when the second push(5) arrives and throttling(5) is called, the
063    // current cyclePushSize is 1000 bytes, this should make throttler1
064    // sleep 1000/100 = 10 cycles = 1s and make throttler2 sleep 1000/10
065    // = 100 cycles = 10s before the second push occurs -- amortize case
066    // after amortizing, both cycleStartTick and cyclePushSize are reset
067    //
068    // Note: in a slow machine, the sleep interval might be less than ideal ticks.
069    // If it is 75% of expected value, its is still acceptable.
070    if (ticks1 != 1000 && ticks1 != 999) {
071      assertTrue(ticks1 >= 750 && ticks1 <= 1000);
072    }
073    if (ticks2 != 10000 && ticks2 != 9999) {
074      assertTrue(ticks2 >= 7500 && ticks2 <= 10000);
075    }
076
077    throttler1.resetStartTick();
078    throttler2.resetStartTick();
079
080    throttler1.addPushSize(5);
081    throttler2.addPushSize(5);
082
083    ticks1 = throttler1.getNextSleepInterval(45);
084    ticks2 = throttler2.getNextSleepInterval(45);
085
086    // 3. when the third push(45) arrives and throttling(45) is called, the
087    // current cyclePushSize is 5 bytes, 50-byte makes throttler1 no
088    // sleep, but can make throttler2 delay to next cycle
089    // note: in real case, sleep time should cover time elapses during push
090    // operation
091    assertTrue(ticks1 == 0);
092    if (ticks2 != 100 && ticks2 != 99) {
093      assertTrue(ticks1 >= 75 && ticks1 <= 100);
094    }
095
096    throttler2.resetStartTick();
097
098    throttler1.addPushSize(45);
099    throttler2.addPushSize(45);
100
101    ticks1 = throttler1.getNextSleepInterval(60);
102    ticks2 = throttler2.getNextSleepInterval(60);
103
104    // 4. when the fourth push(60) arrives and throttling(60) is called, throttler1
105    // delay to next cycle since 45+60 == 105; and throttler2 should firstly sleep
106    // ceiling(45/10)= 5 cycles = 500ms to amortize previous push
107    //
108    // Note: in real case, sleep time should cover time elapses during push operation
109    if (ticks1 != 100 && ticks1 != 99) {
110      assertTrue(ticks1 >= 75 && ticks1 <= 100);
111    }
112    if (ticks2 != 500 && ticks2 != 499) {
113      assertTrue(ticks1 >= 375 && ticks1 <= 500);
114    }
115  }
116}