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.client;
019
020import static org.junit.jupiter.api.Assertions.assertEquals;
021import static org.junit.jupiter.api.Assertions.assertTrue;
022
023import org.apache.hadoop.conf.Configuration;
024import org.apache.hadoop.hbase.ServerName;
025import org.apache.hadoop.hbase.client.backoff.ExponentialClientBackoffPolicy;
026import org.apache.hadoop.hbase.client.backoff.ServerStatistics;
027import org.apache.hadoop.hbase.testclassification.ClientTests;
028import org.apache.hadoop.hbase.testclassification.SmallTests;
029import org.apache.hadoop.hbase.util.Bytes;
030import org.junit.jupiter.api.Tag;
031import org.junit.jupiter.api.Test;
032import org.mockito.Mockito;
033
034import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
035import org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos;
036
037@Tag(ClientTests.TAG)
038@Tag(SmallTests.TAG)
039public class TestClientExponentialBackoff {
040
041  ServerName server = Mockito.mock(ServerName.class);
042  byte[] regionname = Bytes.toBytes("region");
043
044  @Test
045  public void testNulls() {
046    Configuration conf = new Configuration(false);
047    ExponentialClientBackoffPolicy backoff = new ExponentialClientBackoffPolicy(conf);
048    assertEquals(0, backoff.getBackoffTime(null, null, null));
049
050    // server name doesn't matter to calculation, but check it now anyways
051    assertEquals(0, backoff.getBackoffTime(server, null, null));
052    assertEquals(0, backoff.getBackoffTime(server, regionname, null));
053
054    // check when no stats for the region yet
055    ServerStatistics stats = new ServerStatistics();
056    assertEquals(0, backoff.getBackoffTime(server, regionname, stats));
057  }
058
059  @Test
060  public void testMaxLoad() {
061    Configuration conf = new Configuration(false);
062    ExponentialClientBackoffPolicy backoff = new ExponentialClientBackoffPolicy(conf);
063
064    ServerStatistics stats = new ServerStatistics();
065    update(stats, 100);
066    assertEquals(ExponentialClientBackoffPolicy.DEFAULT_MAX_BACKOFF,
067      backoff.getBackoffTime(server, regionname, stats));
068
069    // another policy with a different max timeout
070    long max = 100;
071    conf.setLong(ExponentialClientBackoffPolicy.MAX_BACKOFF_KEY, max);
072    ExponentialClientBackoffPolicy backoffShortTimeout = new ExponentialClientBackoffPolicy(conf);
073    assertEquals(max, backoffShortTimeout.getBackoffTime(server, regionname, stats));
074
075    // test beyond 100 still doesn't exceed the max
076    update(stats, 101);
077    assertEquals(ExponentialClientBackoffPolicy.DEFAULT_MAX_BACKOFF,
078      backoff.getBackoffTime(server, regionname, stats));
079    assertEquals(max, backoffShortTimeout.getBackoffTime(server, regionname, stats));
080
081    // and that when we are below 100, its less than the max timeout
082    update(stats, 99);
083    assertTrue(backoff.getBackoffTime(server, regionname, stats)
084        < ExponentialClientBackoffPolicy.DEFAULT_MAX_BACKOFF);
085    assertTrue(backoffShortTimeout.getBackoffTime(server, regionname, stats) < max);
086  }
087
088  /**
089   * Make sure that we get results in the order that we expect - backoff for a load of 1 should less
090   * than backoff for 10, which should be less than that for 50.
091   */
092  @Test
093  public void testResultOrdering() {
094    Configuration conf = new Configuration(false);
095    // make the max timeout really high so we get differentiation between load factors
096    conf.setLong(ExponentialClientBackoffPolicy.MAX_BACKOFF_KEY, Integer.MAX_VALUE);
097    ExponentialClientBackoffPolicy backoff = new ExponentialClientBackoffPolicy(conf);
098
099    ServerStatistics stats = new ServerStatistics();
100    long previous = backoff.getBackoffTime(server, regionname, stats);
101    for (int i = 1; i <= 100; i++) {
102      update(stats, i);
103      long next = backoff.getBackoffTime(server, regionname, stats);
104      assertTrue(previous < next, "Previous backoff time" + previous + " >= " + next
105        + ", the next backoff time for " + "load " + i);
106      previous = next;
107    }
108  }
109
110  @Test
111  public void testHeapOccupancyPolicy() {
112    Configuration conf = new Configuration(false);
113    ExponentialClientBackoffPolicy backoff = new ExponentialClientBackoffPolicy(conf);
114
115    ServerStatistics stats = new ServerStatistics();
116    long backoffTime;
117
118    update(stats, 0, 95, 0);
119    backoffTime = backoff.getBackoffTime(server, regionname, stats);
120    assertTrue(backoffTime > 0, "Heap occupancy at low watermark had no effect");
121
122    long previous = backoffTime;
123    update(stats, 0, 96, 0);
124    backoffTime = backoff.getBackoffTime(server, regionname, stats);
125    assertTrue(backoffTime > previous,
126      "Increase above low watermark should have increased backoff");
127
128    update(stats, 0, 98, 0);
129    backoffTime = backoff.getBackoffTime(server, regionname, stats);
130    assertEquals(ExponentialClientBackoffPolicy.DEFAULT_MAX_BACKOFF, backoffTime,
131      "We should be using max backoff when at high watermark");
132  }
133
134  @Test
135  public void testCompactionPressurePolicy() {
136    Configuration conf = new Configuration(false);
137    ExponentialClientBackoffPolicy backoff = new ExponentialClientBackoffPolicy(conf);
138
139    ServerStatistics stats = new ServerStatistics();
140    long backoffTime;
141
142    update(stats, 0, 0, 0);
143    backoffTime = backoff.getBackoffTime(server, regionname, stats);
144    assertTrue(backoffTime == 0, "Compaction pressure has no effect");
145
146    long previous = backoffTime;
147    update(stats, 0, 0, 50);
148    backoffTime = backoff.getBackoffTime(server, regionname, stats);
149    assertTrue(backoffTime > previous, "Compaction pressure should be bigger");
150
151    update(stats, 0, 0, 100);
152    backoffTime = backoff.getBackoffTime(server, regionname, stats);
153    assertEquals(ExponentialClientBackoffPolicy.DEFAULT_MAX_BACKOFF, backoffTime,
154      "under heavy compaction pressure");
155  }
156
157  private void update(ServerStatistics stats, int load) {
158    ClientProtos.RegionLoadStats stat =
159      ClientProtos.RegionLoadStats.newBuilder().setMemStoreLoad(load).build();
160    stats.update(regionname, ProtobufUtil.createRegionLoadStats(stat));
161  }
162
163  private void update(ServerStatistics stats, int memstoreLoad, int heapOccupancy,
164    int compactionPressure) {
165    ClientProtos.RegionLoadStats stat =
166      ClientProtos.RegionLoadStats.newBuilder().setMemStoreLoad(memstoreLoad)
167        .setHeapOccupancy(heapOccupancy).setCompactionPressure(compactionPressure).build();
168    stats.update(regionname, ProtobufUtil.createRegionLoadStats(stat));
169  }
170}