/*
* 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.geode.distributed.internal;
import static org.junit.Assert.*;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.apache.geode.cache.server.ServerLoad;
import org.apache.geode.test.junit.categories.UnitTest;
/**
* Tests the functionality of the LocatorLoadSnapshot, which is the data structure that is used in
* the locator to compare the load between multiple servers.
*/
@Category(UnitTest.class)
public class LocatorLoadSnapshotJUnitTest {
/**
* Test to make sure than an empty snapshot returns the correct values.
*/
@Test
public void testEmptySnapshot() {
LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
assertNull(sn.getServerForConnection("group", Collections.EMPTY_SET));
assertNull(sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(Collections.EMPTY_LIST, sn.getServersForQueue(null, Collections.EMPTY_SET, 5));
}
/**
* Test a snapshot with two servers. The servers are initialized with unequal load, and then and
* then we test that after several requests, the load balancer starts sending connections to the
* second server.
*/
@Test
public void testTwoServers() {
LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
ServerLocation l1 = new ServerLocation("localhost", 1);
ServerLocation l2 = new ServerLocation("localhost", 2);
ServerLoad ld1 = new ServerLoad(3, 1, 1.01f, 1);
ServerLoad ld2 = new ServerLoad(5, .2f, 1f, .2f);
sn.addServer(l1, new String[0], ld1);
sn.addServer(l2, new String[0], ld2);
HashMap expectedLoad = new HashMap();
expectedLoad.put(l1, ld1);
expectedLoad.put(l2, ld2);
assertEquals(expectedLoad, sn.getLoadMap());
assertNull(sn.getServerForConnection("group", Collections.EMPTY_SET));
assertEquals(Collections.EMPTY_LIST, sn.getServersForQueue("group", Collections.EMPTY_SET, 5));
assertEquals(l1, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(l1, sn.getServerForConnection(null, Collections.EMPTY_SET));
// the load should be equal here, so we don't know which server to expect
sn.getServerForConnection(null, Collections.EMPTY_SET);
sn.getServerForConnection(null, Collections.EMPTY_SET);
assertEquals(l2, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(l2, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(Collections.singletonList(l2),
sn.getServersForQueue(null, Collections.EMPTY_SET, 1));
assertEquals(Collections.singletonList(l1),
sn.getServersForQueue(null, Collections.EMPTY_SET, 1));
assertEquals(Collections.singletonList(l2),
sn.getServersForQueue(null, Collections.EMPTY_SET, 1));
assertEquals(Arrays.asList(new ServerLocation[] {l2, l1}),
sn.getServersForQueue(null, Collections.EMPTY_SET, 5));
assertEquals(Arrays.asList(new ServerLocation[] {l2, l1}),
sn.getServersForQueue(null, Collections.EMPTY_SET, -1));
}
/**
* Test the updateLoad method. The snapshot should use the new load when choosing a server.
*/
@Test
public void testUpdateLoad() {
LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
ServerLocation l1 = new ServerLocation("localhost", 1);
ServerLocation l2 = new ServerLocation("localhost", 2);
sn.addServer(l1, new String[0], new ServerLoad(1, 1, 1, 1));
sn.addServer(l2, new String[0], new ServerLoad(100, .2f, 1, .2f));
assertEquals(l1, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(l1, sn.getServerForConnection(null, Collections.EMPTY_SET));
sn.updateLoad(l1, new ServerLoad(200, 1, 1, 1));
assertEquals(l2, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(l2, sn.getServerForConnection(null, Collections.EMPTY_SET));
}
/**
* Test that we can remove a server from the snapshot. It should not suggest that server after it
* has been removed.
*/
@Test
public void testRemoveServer() {
LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
ServerLocation l1 = new ServerLocation("localhost", 1);
ServerLocation l2 = new ServerLocation("localhost", 2);
sn.addServer(l1, new String[0], new ServerLoad(1, 1, 1, 1));
sn.addServer(l2, new String[0], new ServerLoad(100, .2f, 10, .2f));
assertEquals(l1, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(Arrays.asList(new ServerLocation[] {l1, l2}),
sn.getServersForQueue(null, Collections.EMPTY_SET, -1));
sn.removeServer(l1);
assertEquals(l2, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(Collections.singletonList(l2),
sn.getServersForQueue(null, Collections.EMPTY_SET, -1));
}
/**
* Test of server groups. Make sure that the snapshot returns only servers from the correct group.
*/
@Test
public void testGroups() {
LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
ServerLocation l1 = new ServerLocation("localhost", 1);
ServerLocation l2 = new ServerLocation("localhost", 2);
sn.addServer(l1, new String[] {"a", "b"}, new ServerLoad(1, 1, 1, 1));
sn.addServer(l2, new String[] {"b", "c"}, new ServerLoad(1, 1, 1, 1));
assertNotNull(sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(l1, sn.getServerForConnection("a", Collections.EMPTY_SET));
assertEquals(l2, sn.getServerForConnection("c", Collections.EMPTY_SET));
sn.updateLoad(l1, new ServerLoad(10, 1, 1, 1));
assertEquals(l2, sn.getServerForConnection("b", Collections.EMPTY_SET));
sn.updateLoad(l2, new ServerLoad(100, 1, 1, 1));
assertEquals(l1, sn.getServerForConnection("b", Collections.EMPTY_SET));
assertEquals(Arrays.asList(new ServerLocation[] {l1}),
sn.getServersForQueue("a", Collections.EMPTY_SET, -1));
assertEquals(Arrays.asList(new ServerLocation[] {l2}),
sn.getServersForQueue("c", Collections.EMPTY_SET, -1));
assertEquals(Arrays.asList(new ServerLocation[] {l1, l2}),
sn.getServersForQueue("b", Collections.EMPTY_SET, -1));
assertEquals(Arrays.asList(new ServerLocation[] {l1, l2}),
sn.getServersForQueue(null, Collections.EMPTY_SET, -1));
assertEquals(Arrays.asList(new ServerLocation[] {l1, l2}),
sn.getServersForQueue("b", Collections.EMPTY_SET, 5));
sn.removeServer(l1);
assertEquals(l2, sn.getServerForConnection("b", Collections.EMPTY_SET));
assertEquals(l2, sn.getServerForConnection("b", Collections.EMPTY_SET));
assertNull(sn.getServerForConnection("a", Collections.EMPTY_SET));
assertEquals(l2, sn.getServerForConnection("c", Collections.EMPTY_SET));
assertEquals(Arrays.asList(new ServerLocation[] {}),
sn.getServersForQueue("a", Collections.EMPTY_SET, -1));
assertEquals(Arrays.asList(new ServerLocation[] {l2}),
sn.getServersForQueue("b", Collections.EMPTY_SET, 5));
}
/**
* Test to make sure that we balancing three servers with interecting groups correctly.
*/
@Test
public void testIntersectingGroups() {
LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
ServerLocation l1 = new ServerLocation("localhost", 1);
ServerLocation l2 = new ServerLocation("localhost", 2);
ServerLocation l3 = new ServerLocation("localhost", 3);
sn.addServer(l1, new String[] {"a",}, new ServerLoad(0, 1, 0, 1));
sn.addServer(l2, new String[] {"a", "b"}, new ServerLoad(0, 1, 0, 1));
sn.addServer(l3, new String[] {"b"}, new ServerLoad(0, 1, 0, 1));
// Test with interleaving requests for either group
for (int i = 0; i < 60; i++) {
ServerLocation l = sn.getServerForConnection("a", Collections.EMPTY_SET);
assertTrue(l1.equals(l) || l2.equals(l));
l = sn.getServerForConnection("b", Collections.EMPTY_SET);
assertTrue(l2.equals(l) || l3.equals(l));
}
Map expected = new HashMap();
ServerLoad expectedLoad = new ServerLoad(40f, 1f, 0f, 1f);
expected.put(l1, expectedLoad);
expected.put(l2, expectedLoad);
expected.put(l3, expectedLoad);
assertEquals(expected, sn.getLoadMap());
sn.updateLoad(l1, new ServerLoad(0, 1, 0, 1));
sn.updateLoad(l2, new ServerLoad(0, 1, 0, 1));
sn.updateLoad(l3, new ServerLoad(0, 1, 0, 1));
// Now do the same test, but make all the requests for one group first,
// then the second group.
for (int i = 0; i < 60; i++) {
ServerLocation l = sn.getServerForConnection("a", Collections.EMPTY_SET);
assertTrue(l1.equals(l) || l2.equals(l));
}
expected = new HashMap();
expected.put(l1, new ServerLoad(30f, 1f, 0f, 1f));
expected.put(l2, new ServerLoad(30f, 1f, 0f, 1f));
expected.put(l3, new ServerLoad(0f, 1f, 0f, 1f));
assertEquals(expected, sn.getLoadMap());
for (int i = 0; i < 60; i++) {
ServerLocation l = sn.getServerForConnection("b", Collections.EMPTY_SET);
assertTrue(l2.equals(l) || l3.equals(l));
}
// The load can't be completely balanced, because
// We already had 30 connections from group a on server l2.
// But we expect that l3 should have received most of the connections
// for group b, because it started out with 0.
expected = new HashMap();
expected.put(l1, new ServerLoad(30f, 1f, 0f, 1f));
expected.put(l2, new ServerLoad(45f, 1f, 0f, 1f));
expected.put(l3, new ServerLoad(45f, 1f, 0f, 1f));
assertEquals(expected, sn.getLoadMap());
}
/**
* Test that we can specify a list of servers to exclude and the snapshot honors the request when
* picking the best server.
*/
@Test
public void testExcludes() {
LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
ServerLocation l1 = new ServerLocation("localhost", 1);
ServerLocation l2 = new ServerLocation("localhost", 2);
sn.addServer(l1, new String[0], new ServerLoad(1, 1, 1, 1));
sn.addServer(l2, new String[0], new ServerLoad(100, 1, 100, 1));
HashSet excludeAll = new HashSet();
excludeAll.add(l1);
excludeAll.add(l2);
assertEquals(l1, sn.getServerForConnection(null, Collections.EMPTY_SET));
assertEquals(l2, sn.getServerForConnection(null, Collections.singleton(l1)));
assertEquals(null, sn.getServerForConnection(null, excludeAll));
assertEquals(Arrays.asList(new ServerLocation[] {l2}),
sn.getServersForQueue(null, Collections.singleton(l1), 3));
assertEquals(Arrays.asList(new ServerLocation[] {}),
sn.getServersForQueue(null, excludeAll, 3));
}
@Test
public void testAreBalanced() {
final LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
assertTrue(sn.hasBalancedConnections(null));
assertTrue(sn.hasBalancedConnections("a"));
final ServerLocation l1 = new ServerLocation("localhost", 1);
final ServerLocation l2 = new ServerLocation("localhost", 2);
final ServerLocation l3 = new ServerLocation("localhost", 3);
sn.addServer(l1, new String[] {"a"}, new ServerLoad(0, 1, 0, 1));
sn.addServer(l2, new String[] {"a", "b"}, new ServerLoad(0, 1, 0, 1));
sn.addServer(l3, new String[] {"b"}, new ServerLoad(0, 1, 0, 1));
assertTrue(sn.hasBalancedConnections(null));
assertTrue(sn.hasBalancedConnections("a"));
assertTrue(sn.hasBalancedConnections("b"));
sn.updateLoad(l1, new ServerLoad(1, 1, 0, 1));
assertTrue(sn.hasBalancedConnections(null));
assertTrue(sn.hasBalancedConnections("a"));
assertTrue(sn.hasBalancedConnections("b"));
sn.updateLoad(l2, new ServerLoad(2, 1, 0, 1));
assertFalse(sn.hasBalancedConnections(null));
assertTrue(sn.hasBalancedConnections("a"));
assertFalse(sn.hasBalancedConnections("b"));
}
}