View Javadoc

1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.hadoop.hbase.replication.regionserver;
20  
21  import static org.junit.Assert.assertEquals;
22  import static org.junit.Assert.assertTrue;
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  
27  import org.apache.hadoop.hbase.testclassification.SmallTests;
28  import org.junit.Test;
29  import org.junit.experimental.categories.Category;
30  
31  @Category(SmallTests.class)
32  public class TestReplicationThrottler {
33  
34    private static final Log LOG = LogFactory.getLog(TestReplicationThrottler.class);
35  
36    /**
37     * unit test for throttling
38     */
39    @Test(timeout=10000)
40    public void testThrottling() {
41      LOG.info("testThrottling");
42  
43      // throttle bandwidth is 100 and 10 bytes/cycle respectively
44      ReplicationThrottler throttler1 = new ReplicationThrottler(100);
45      ReplicationThrottler throttler2 = new ReplicationThrottler(10);
46  
47      long ticks1 = throttler1.getNextSleepInterval(1000);
48      long ticks2 = throttler2.getNextSleepInterval(1000);
49  
50      // 1. the first push size is 1000, though 1000 bytes exceeds 100/10
51      //    bandwidthes, but no sleep since it's the first push of current
52      //    cycle, amortizing occurs when next push arrives
53      assertEquals(0, ticks1);
54      assertEquals(0, ticks2);
55  
56      throttler1.addPushSize(1000);
57      throttler2.addPushSize(1000);
58  
59      ticks1 = throttler1.getNextSleepInterval(5);
60      ticks2 = throttler2.getNextSleepInterval(5);
61  
62      // 2. when the second push(5) arrives and throttling(5) is called, the
63      //    current cyclePushSize is 1000 bytes, this should make throttler1
64      //    sleep 1000/100 = 10 cycles = 1s and make throttler2 sleep 1000/10
65      //    = 100 cycles = 10s before the second push occurs -- amortize case
66      //    after amortizing, both cycleStartTick and cyclePushSize are reset
67      //
68      // Note: in a slow machine, the sleep interval might be less than ideal ticks.
69      // If it is 75% of expected value, its is still acceptable.
70      if (ticks1 != 1000 && ticks1 != 999) {
71        assertTrue(ticks1 >= 750 && ticks1 <=1000);
72      }
73      if (ticks2 != 10000 && ticks2 != 9999) {
74        assertTrue(ticks2 >= 7500 && ticks2 <=10000);
75      }
76  
77      throttler1.resetStartTick();
78      throttler2.resetStartTick();
79  
80      throttler1.addPushSize(5);
81      throttler2.addPushSize(5);
82  
83      ticks1 = throttler1.getNextSleepInterval(45);
84      ticks2 = throttler2.getNextSleepInterval(45);
85  
86      // 3. when the third push(45) arrives and throttling(45) is called, the
87      //    current cyclePushSize is 5 bytes, 50-byte makes throttler1 no
88      //    sleep, but can make throttler2 delay to next cycle
89      // note: in real case, sleep time should cover time elapses during push
90      //       operation
91      assertTrue(ticks1 == 0);
92      if (ticks2 != 100 && ticks2 != 99) {
93        assertTrue(ticks1 >= 75 && ticks1 <=100);
94      }
95  
96      throttler2.resetStartTick();
97  
98      throttler1.addPushSize(45);
99      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 }