/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.master.balancer;
import static org.junit.Assert.assertEquals;
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.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import org.apache.commons.lang.ArrayUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.ClusterStatus;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HBaseIOException;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.MediumTests;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.master.LoadBalancer;
import org.apache.hadoop.hbase.master.MasterServices;
import org.apache.hadoop.hbase.master.RegionPlan;
import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.RegionReplicaUtil;
import org.apache.hadoop.hbase.master.RackManager;
import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.MoveRegionAction;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.mockito.Mockito;
import com.google.common.collect.Lists;
@Category(MediumTests.class)
public class TestBaseLoadBalancer extends BalancerTestBase {
private static LoadBalancer loadBalancer;
private static final Log LOG = LogFactory.getLog(TestBaseLoadBalancer.class);
private static final ServerName master = ServerName.valueOf("fake-master", 0, 1L);
private static RackManager rackManager;
private static final int NUM_SERVERS = 15;
private static ServerName[] servers = new ServerName[NUM_SERVERS];
int[][] regionsAndServersMocks = new int[][] {
// { num regions, num servers }
new int[] { 0, 0 }, new int[] { 0, 1 }, new int[] { 1, 1 }, new int[] { 2, 1 },
new int[] { 10, 1 }, new int[] { 1, 2 }, new int[] { 2, 2 }, new int[] { 3, 2 },
new int[] { 1, 3 }, new int[] { 2, 3 }, new int[] { 3, 3 }, new int[] { 25, 3 },
new int[] { 2, 10 }, new int[] { 2, 100 }, new int[] { 12, 10 }, new int[] { 12, 100 }, };
@BeforeClass
public static void beforeAllTests() throws Exception {
Configuration conf = HBaseConfiguration.create();
loadBalancer = new MockBalancer();
loadBalancer.setConf(conf);
MasterServices st = Mockito.mock(MasterServices.class);
Mockito.when(st.getServerName()).thenReturn(master);
loadBalancer.setMasterServices(st);
// Set up the rack topologies (5 machines per rack)
rackManager = Mockito.mock(RackManager.class);
for (int i = 0; i < NUM_SERVERS; i++) {
servers[i] = ServerName.valueOf("foo"+i+":1234",-1);
if (i < 5) {
Mockito.when(rackManager.getRack(servers[i])).thenReturn("rack1");
}
if (i >= 5 && i < 10) {
Mockito.when(rackManager.getRack(servers[i])).thenReturn("rack2");
}
if (i >= 10) {
Mockito.when(rackManager.getRack(servers[i])).thenReturn("rack3");
}
}
}
public static class MockBalancer extends BaseLoadBalancer {
@Override
public List<RegionPlan> balanceCluster(Map<ServerName, List<HRegionInfo>> clusterState) {
return null;
}
}
/**
* Tests immediate assignment.
*
* Invariant is that all regions have an assignment.
*
* @throws Exception
*/
@Test
public void testImmediateAssignment() throws Exception {
for (int[] mock : regionsAndServersMocks) {
LOG.debug("testImmediateAssignment with " + mock[0] + " regions and " + mock[1] + " servers");
List<HRegionInfo> regions = randomRegions(mock[0]);
List<ServerAndLoad> servers = randomServers(mock[1], 0);
List<ServerName> list = getListOfServerNames(servers);
Map<HRegionInfo, ServerName> assignments = loadBalancer.immediateAssignment(regions, list);
assertImmediateAssignment(regions, list, assignments);
returnRegions(regions);
returnServers(list);
}
}
/**
* All regions have an assignment.
* @param regions
* @param servers
* @param assignments
*/
private void assertImmediateAssignment(List<HRegionInfo> regions, List<ServerName> servers,
Map<HRegionInfo, ServerName> assignments) {
for (HRegionInfo region : regions) {
assertTrue(assignments.containsKey(region));
}
}
/**
* Tests the bulk assignment used during cluster startup.
*
* Round-robin. Should yield a balanced cluster so same invariant as the load
* balancer holds, all servers holding either floor(avg) or ceiling(avg).
*
* @throws Exception
*/
@Test
public void testBulkAssignment() throws Exception {
for (int[] mock : regionsAndServersMocks) {
LOG.debug("testBulkAssignment with " + mock[0] + " regions and " + mock[1] + " servers");
List<HRegionInfo> regions = randomRegions(mock[0]);
List<ServerAndLoad> servers = randomServers(mock[1], 0);
List<ServerName> list = getListOfServerNames(servers);
Map<ServerName, List<HRegionInfo>> assignments =
loadBalancer.roundRobinAssignment(regions, list);
float average = (float) regions.size() / servers.size();
int min = (int) Math.floor(average);
int max = (int) Math.ceil(average);
if (assignments != null && !assignments.isEmpty()) {
for (List<HRegionInfo> regionList : assignments.values()) {
assertTrue(regionList.size() == min || regionList.size() == max);
}
}
returnRegions(regions);
returnServers(list);
}
}
/**
* Test the cluster startup bulk assignment which attempts to retain
* assignment info.
* @throws Exception
*/
@Test
public void testRetainAssignment() throws Exception {
// Test simple case where all same servers are there
List<ServerAndLoad> servers = randomServers(10, 10);
List<HRegionInfo> regions = randomRegions(100);
Map<HRegionInfo, ServerName> existing = new TreeMap<HRegionInfo, ServerName>();
for (int i = 0; i < regions.size(); i++) {
ServerName sn = servers.get(i % servers.size()).getServerName();
// The old server would have had same host and port, but different
// start code!
ServerName snWithOldStartCode =
ServerName.valueOf(sn.getHostname(), sn.getPort(), sn.getStartcode() - 10);
existing.put(regions.get(i), snWithOldStartCode);
}
List<ServerName> listOfServerNames = getListOfServerNames(servers);
Map<ServerName, List<HRegionInfo>> assignment =
loadBalancer.retainAssignment(existing, listOfServerNames);
assertRetainedAssignment(existing, listOfServerNames, assignment);
// Include two new servers that were not there before
List<ServerAndLoad> servers2 = new ArrayList<ServerAndLoad>(servers);
servers2.add(randomServer(10));
servers2.add(randomServer(10));
listOfServerNames = getListOfServerNames(servers2);
assignment = loadBalancer.retainAssignment(existing, listOfServerNames);
assertRetainedAssignment(existing, listOfServerNames, assignment);
// Remove two of the servers that were previously there
List<ServerAndLoad> servers3 = new ArrayList<ServerAndLoad>(servers);
servers3.remove(0);
servers3.remove(0);
listOfServerNames = getListOfServerNames(servers3);
assignment = loadBalancer.retainAssignment(existing, listOfServerNames);
assertRetainedAssignment(existing, listOfServerNames, assignment);
}
@Test
public void testRegionAvailability() throws Exception {
// Create a cluster with a few servers, assign them to specific racks
// then assign some regions. The tests should check whether moving a
// replica from one node to a specific other node or rack lowers the
// availability of the region or not
List<HRegionInfo> list0 = new ArrayList<HRegionInfo>();
List<HRegionInfo> list1 = new ArrayList<HRegionInfo>();
List<HRegionInfo> list2 = new ArrayList<HRegionInfo>();
// create a region (region1)
HRegionInfo hri1 = new HRegionInfo(
TableName.valueOf("table"), "key1".getBytes(), "key2".getBytes(),
false, 100);
// create a replica of the region (replica_of_region1)
HRegionInfo hri2 = RegionReplicaUtil.getRegionInfoForReplica(hri1, 1);
// create a second region (region2)
HRegionInfo hri3 = new HRegionInfo(
TableName.valueOf("table"), "key2".getBytes(), "key3".getBytes(),
false, 101);
list0.add(hri1); //only region1
list1.add(hri2); //only replica_of_region1
list2.add(hri3); //only region2
Map<ServerName, List<HRegionInfo>> clusterState =
new LinkedHashMap<ServerName, List<HRegionInfo>>();
clusterState.put(servers[0], list0); //servers[0] hosts region1
clusterState.put(servers[1], list1); //servers[1] hosts replica_of_region1
clusterState.put(servers[2], list2); //servers[2] hosts region2
// create a cluster with the above clusterState. The way in which the
// cluster is created (constructor code) would make sure the indices of
// the servers are in the order in which it is inserted in the clusterState
// map (linkedhashmap is important). A similar thing applies to the region lists
Cluster cluster = new Cluster(master, clusterState, null, null, null, null, rackManager);
// check whether a move of region1 from servers[0] to servers[1] would lower
// the availability of region1
assertTrue(cluster.wouldLowerAvailability(hri1, servers[1]));
// check whether a move of region1 from servers[0] to servers[2] would lower
// the availability of region1
assertTrue(!cluster.wouldLowerAvailability(hri1, servers[2]));
// check whether a move of replica_of_region1 from servers[0] to servers[2] would lower
// the availability of replica_of_region1
assertTrue(!cluster.wouldLowerAvailability(hri2, servers[2]));
// check whether a move of region2 from servers[0] to servers[1] would lower
// the availability of region2
assertTrue(!cluster.wouldLowerAvailability(hri3, servers[1]));
// now lets have servers[1] host replica_of_region2
list1.add(RegionReplicaUtil.getRegionInfoForReplica(hri3, 1));
// create a new clusterState with the above change
cluster = new Cluster(master, clusterState, null, null, null, null, rackManager);
// now check whether a move of a replica from servers[0] to servers[1] would lower
// the availability of region2
assertTrue(cluster.wouldLowerAvailability(hri3, servers[1]));
// start over again
clusterState.clear();
clusterState.put(servers[0], list0); //servers[0], rack1 hosts region1
clusterState.put(servers[5], list1); //servers[5], rack2 hosts replica_of_region1 and replica_of_region2
clusterState.put(servers[6], list2); //servers[6], rack2 hosts region2
clusterState.put(servers[10], new ArrayList<HRegionInfo>()); //servers[10], rack3 hosts no region
// create a cluster with the above clusterState
cluster = new Cluster(master, clusterState, null, null, null, null, rackManager);
// check whether a move of region1 from servers[0],rack1 to servers[6],rack2 would
// lower the availability
assertTrue(cluster.wouldLowerAvailability(hri1, servers[0]));
// now create a cluster without the rack manager
cluster = new Cluster(master, clusterState, null, null, null, null, null);
// now repeat check whether a move of region1 from servers[0] to servers[6] would
// lower the availability
assertTrue(!cluster.wouldLowerAvailability(hri1, servers[6]));
}
@Test
public void testRegionAvailabilityWithRegionMoves() throws Exception {
List<HRegionInfo> list0 = new ArrayList<HRegionInfo>();
List<HRegionInfo> list1 = new ArrayList<HRegionInfo>();
List<HRegionInfo> list2 = new ArrayList<HRegionInfo>();
// create a region (region1)
HRegionInfo hri1 = new HRegionInfo(
TableName.valueOf("table"), "key1".getBytes(), "key2".getBytes(),
false, 100);
// create a replica of the region (replica_of_region1)
HRegionInfo hri2 = RegionReplicaUtil.getRegionInfoForReplica(hri1, 1);
// create a second region (region2)
HRegionInfo hri3 = new HRegionInfo(
TableName.valueOf("table"), "key2".getBytes(), "key3".getBytes(),
false, 101);
list0.add(hri1); //only region1
list1.add(hri2); //only replica_of_region1
list2.add(hri3); //only region2
Map<ServerName, List<HRegionInfo>> clusterState =
new LinkedHashMap<ServerName, List<HRegionInfo>>();
clusterState.put(servers[0], list0); //servers[0] hosts region1
clusterState.put(servers[1], list1); //servers[1] hosts replica_of_region1
clusterState.put(servers[2], list2); //servers[2] hosts region2
// create a cluster with the above clusterState. The way in which the
// cluster is created (constructor code) would make sure the indices of
// the servers are in the order in which it is inserted in the clusterState
// map (linkedhashmap is important).
Cluster cluster = new Cluster(master, clusterState, null, null, null, null, rackManager);
// check whether moving region1 from servers[1] to servers[2] would lower availability
assertTrue(!cluster.wouldLowerAvailability(hri1, servers[2]));
// now move region1 from servers[0] to servers[2]
cluster.doAction(new MoveRegionAction(0, 0, 2));
// now repeat check whether moving region1 from servers[1] to servers[2]
// would lower availability
assertTrue(cluster.wouldLowerAvailability(hri1, servers[2]));
// start over again
clusterState.clear();
List<HRegionInfo> list3 = new ArrayList<HRegionInfo>();
HRegionInfo hri4 = RegionReplicaUtil.getRegionInfoForReplica(hri3, 1);
list3.add(hri4);
clusterState.put(servers[0], list0); //servers[0], rack1 hosts region1
clusterState.put(servers[5], list1); //servers[5], rack2 hosts replica_of_region1
clusterState.put(servers[6], list2); //servers[6], rack2 hosts region2
clusterState.put(servers[12], list3); //servers[12], rack3 hosts replica_of_region2
// create a cluster with the above clusterState
cluster = new Cluster(master, clusterState, null, null, null, null, rackManager);
// check whether a move of replica_of_region2 from servers[12],rack3 to servers[0],rack1 would
// lower the availability
assertTrue(!cluster.wouldLowerAvailability(hri4, servers[0]));
// now move region2 from servers[6],rack2 to servers[0],rack1
cluster.doAction(new MoveRegionAction(2, 2, 0));
// now repeat check if replica_of_region2 from servers[12],rack3 to servers[0],rack1 would
// lower the availability
assertTrue(cluster.wouldLowerAvailability(hri3, servers[0]));
}
private List<ServerName> getListOfServerNames(final List<ServerAndLoad> sals) {
List<ServerName> list = new ArrayList<ServerName>();
for (ServerAndLoad e : sals) {
list.add(e.getServerName());
}
return list;
}
/**
* Asserts a valid retained assignment plan.
* <p>
* Must meet the following conditions:
* <ul>
* <li>Every input region has an assignment, and to an online server
* <li>If a region had an existing assignment to a server with the same
* address a a currently online server, it will be assigned to it
* </ul>
* @param existing
* @param servers
* @param assignment
*/
private void assertRetainedAssignment(Map<HRegionInfo, ServerName> existing,
List<ServerName> servers, Map<ServerName, List<HRegionInfo>> assignment) {
// Verify condition 1, every region assigned, and to online server
Set<ServerName> onlineServerSet = new TreeSet<ServerName>(servers);
Set<HRegionInfo> assignedRegions = new TreeSet<HRegionInfo>();
for (Map.Entry<ServerName, List<HRegionInfo>> a : assignment.entrySet()) {
assertTrue("Region assigned to server that was not listed as online",
onlineServerSet.contains(a.getKey()));
for (HRegionInfo r : a.getValue())
assignedRegions.add(r);
}
assertEquals(existing.size(), assignedRegions.size());
// Verify condition 2, if server had existing assignment, must have same
Set<String> onlineHostNames = new TreeSet<String>();
for (ServerName s : servers) {
onlineHostNames.add(s.getHostname());
}
for (Map.Entry<ServerName, List<HRegionInfo>> a : assignment.entrySet()) {
ServerName assignedTo = a.getKey();
for (HRegionInfo r : a.getValue()) {
ServerName address = existing.get(r);
if (address != null && onlineHostNames.contains(address.getHostname())) {
// this region was prevously assigned somewhere, and that
// host is still around, then it should be re-assigned on the
// same host
assertEquals(address.getHostname(), assignedTo.getHostname());
}
}
}
}
@Test
public void testClusterServersWithSameHostPort() {
// tests whether the BaseLoadBalancer.Cluster can be constructed with servers
// sharing same host and port
List<ServerName> servers = getListOfServerNames(randomServers(10, 10));
List<HRegionInfo> regions = randomRegions(101);
Map<ServerName, List<HRegionInfo>> clusterState = new HashMap<ServerName, List<HRegionInfo>>();
assignRegions(regions, servers, clusterState);
// construct another list of servers, but sharing same hosts and ports
List<ServerName> oldServers = new ArrayList<ServerName>(servers.size());
for (ServerName sn : servers) {
// The old server would have had same host and port, but different start code!
oldServers.add(ServerName.valueOf(sn.getHostname(), sn.getPort(), sn.getStartcode() - 10));
}
regions = randomRegions(9); // some more regions
assignRegions(regions, oldServers, clusterState);
// should not throw exception:
BaseLoadBalancer.Cluster cluster = new Cluster(null, clusterState, null, null, null, null, null);
assertEquals(101 + 9, cluster.numRegions);
assertEquals(10, cluster.numServers); // only 10 servers because they share the same host + port
}
private void assignRegions(List<HRegionInfo> regions, List<ServerName> servers,
Map<ServerName, List<HRegionInfo>> clusterState) {
for (int i = 0; i < regions.size(); i++) {
ServerName sn = servers.get(i % servers.size());
List<HRegionInfo> regionsOfServer = clusterState.get(sn);
if (regionsOfServer == null) {
regionsOfServer = new ArrayList<HRegionInfo>(10);
clusterState.put(sn, regionsOfServer);
}
regionsOfServer.add(regions.get(i));
}
}
@Test
public void testClusterRegionLocations() {
// tests whether region locations are handled correctly in Cluster
List<ServerName> servers = getListOfServerNames(randomServers(10, 10));
List<HRegionInfo> regions = randomRegions(101);
Map<ServerName, List<HRegionInfo>> clusterState = new HashMap<ServerName, List<HRegionInfo>>();
assignRegions(regions, servers, clusterState);
// mock block locality for some regions
RegionLocationFinder locationFinder = mock(RegionLocationFinder.class);
// block locality: region:0 => {server:0}
// region:1 => {server:0, server:1}
// region:42 => {server:4, server:9, server:5}
when(locationFinder.getTopBlockLocations(regions.get(0))).thenReturn(
Lists.newArrayList(servers.get(0)));
when(locationFinder.getTopBlockLocations(regions.get(1))).thenReturn(
Lists.newArrayList(servers.get(0), servers.get(1)));
when(locationFinder.getTopBlockLocations(regions.get(42))).thenReturn(
Lists.newArrayList(servers.get(4), servers.get(9), servers.get(5)));
when(locationFinder.getTopBlockLocations(regions.get(43))).thenReturn(
Lists.newArrayList(ServerName.valueOf("foo", 0, 0))); // this server does not exists in clusterStatus
BaseLoadBalancer.Cluster cluster = new Cluster(null, clusterState, null, locationFinder, null, null, null);
int r0 = ArrayUtils.indexOf(cluster.regions, regions.get(0)); // this is ok, it is just a test
int r1 = ArrayUtils.indexOf(cluster.regions, regions.get(1));
int r10 = ArrayUtils.indexOf(cluster.regions, regions.get(10));
int r42 = ArrayUtils.indexOf(cluster.regions, regions.get(42));
int r43 = ArrayUtils.indexOf(cluster.regions, regions.get(43));
int s0 = cluster.serversToIndex.get(servers.get(0).getHostAndPort());
int s1 = cluster.serversToIndex.get(servers.get(1).getHostAndPort());
int s4 = cluster.serversToIndex.get(servers.get(4).getHostAndPort());
int s5 = cluster.serversToIndex.get(servers.get(5).getHostAndPort());
int s9 = cluster.serversToIndex.get(servers.get(9).getHostAndPort());
// region 0 locations
assertEquals(1, cluster.regionLocations[r0].length);
assertEquals(s0, cluster.regionLocations[r0][0]);
// region 1 locations
assertEquals(2, cluster.regionLocations[r1].length);
assertEquals(s0, cluster.regionLocations[r1][0]);
assertEquals(s1, cluster.regionLocations[r1][1]);
// region 10 locations
assertEquals(0, cluster.regionLocations[r10].length);
// region 42 locations
assertEquals(3, cluster.regionLocations[r42].length);
assertEquals(s4, cluster.regionLocations[r42][0]);
assertEquals(s9, cluster.regionLocations[r42][1]);
assertEquals(s5, cluster.regionLocations[r42][2]);
// region 43 locations
assertEquals(1, cluster.regionLocations[r43].length);
assertEquals(-1, cluster.regionLocations[r43][0]);
}
@Test
public void testBackupMastersExcluded() throws HBaseIOException {
ClusterStatus st = Mockito.mock(ClusterStatus.class);
ArrayList<ServerName> backupMasters = new ArrayList<ServerName>();
ServerName backupMaster = ServerName.valueOf("fake-backupmaster", 0, 1L);
backupMasters.add(backupMaster);
BaseLoadBalancer balancer = (BaseLoadBalancer)loadBalancer;
balancer.usingBackupMasters = false;
Mockito.when(st.getBackupMasters()).thenReturn(backupMasters);
loadBalancer.setClusterStatus(st);
assertEquals(backupMasters.size(), balancer.excludedServers.size());
assertTrue(balancer.excludedServers.contains(backupMaster));
// Round robin assignment
List<HRegionInfo> regions = randomRegions(1);
HRegionInfo region = regions.get(0);
assertNull(loadBalancer.randomAssignment(region, backupMasters));
assertNull(loadBalancer.roundRobinAssignment(regions, backupMasters));
HashMap<HRegionInfo, ServerName> assignments = new HashMap<HRegionInfo, ServerName>();
assignments.put(region, backupMaster);
assertNull(loadBalancer.retainAssignment(assignments, backupMasters));
ArrayList<ServerName> servers = new ArrayList<ServerName>(backupMasters);
ServerName sn = ServerName.valueOf("fake-rs", 0, 1L);
servers.add(sn);
assertEquals(sn, loadBalancer.randomAssignment(region, servers));
Map<ServerName, List<HRegionInfo>> plans =
loadBalancer.roundRobinAssignment(regions, servers);
assertEquals(1, plans.size());
assertTrue(plans.get(sn).contains(region));
// Retain assignment
plans = loadBalancer.retainAssignment(assignments, servers);
assertEquals(1, plans.size());
assertTrue(plans.get(sn).contains(region));
// Filter backup masters for balance cluster
Map<ServerName, List<HRegionInfo>> clusterMap =
new HashMap<ServerName, List<HRegionInfo>>();
clusterMap.put(backupMaster, new ArrayList<HRegionInfo>());
clusterMap.put(sn, new ArrayList<HRegionInfo>());
balancer.filterExcludedServers(clusterMap);
assertTrue(clusterMap.containsKey(sn));
assertEquals(1, clusterMap.size());
}
}