HBASE-26872 Load rate calculator for cost functions should be more precise (#4253)

Signed-off-by: Bryan Beaudreault <bbeaudreault@hubspot.com>
Signed-off-by: Viraj Jasani<virajjasani@apache.org>
This commit is contained in:
Xiaolin Ha 2022-03-27 11:12:00 +08:00 committed by GitHub
parent 698937d32b
commit ad70ac2cd1
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2 changed files with 28 additions and 4 deletions

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@ -42,7 +42,7 @@ abstract class CostFromRegionLoadAsRateFunction extends CostFromRegionLoadFuncti
double cost = 0;
do {
double current = getCostFromRl(iter.next());
cost += current - previous;
cost += current >= previous ? current - previous : current;
previous = current;
} while (iter.hasNext());
return Math.max(0, cost / (regionLoadList.size() - 1));

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@ -23,7 +23,6 @@ import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
@ -51,7 +50,6 @@ import org.apache.hadoop.hbase.util.Bytes;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.apache.hbase.thirdparty.org.apache.commons.collections4.CollectionUtils;
@Category({ MasterTests.class, MediumTests.class })
@ -519,6 +517,32 @@ public class TestStochasticLoadBalancer extends StochasticBalancerTestBase {
assertEquals(2.5, result, 0.01);
}
@Test
public void testRegionLoadCostWhenDecrease() {
List<BalancerRegionLoad> regionLoads = new ArrayList<>();
// test region loads of [1,2,1,4]
for (int i = 1; i < 5; i++) {
int load = i == 3 ? 1 : i;
BalancerRegionLoad regionLoad = mock(BalancerRegionLoad.class);
when(regionLoad.getReadRequestsCount()).thenReturn((long)load);
when(regionLoad.getCpRequestsCount()).thenReturn((long)load);
regionLoads.add(regionLoad);
}
Configuration conf = HBaseConfiguration.create();
ReadRequestCostFunction readCostFunction =
new ReadRequestCostFunction(conf);
double rateResult = readCostFunction.getRegionLoadCost(regionLoads);
// read requests are treated as a rate so the average rate here is simply 1
assertEquals(1.67, rateResult, 0.01);
CPRequestCostFunction cpCostFunction =
new CPRequestCostFunction(conf);
rateResult = cpCostFunction.getRegionLoadCost(regionLoads);
// coprocessor requests are treated as a rate so the average rate here is simply 1
assertEquals(1.67, rateResult, 0.01);
}
@Test
public void testLosingRs() throws Exception {
int numNodes = 3;