/*
* Copyright (C) 2012-2015 DataStax Inc.
*
* Licensed 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 com.datastax.driver.core.policies;
import com.datastax.driver.core.*;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;
import static com.datastax.driver.core.Assertions.assertThat;
import static com.datastax.driver.core.TestUtils.nonQuietClusterCloseOptions;
public class RoundRobinPolicyTest {
Logger policyLogger = Logger.getLogger(RoundRobinPolicy.class);
MemoryAppender logs;
QueryTracker queryTracker;
Level originalLevel;
@BeforeMethod(groups = "short")
public void setUp() {
queryTracker = new QueryTracker();
originalLevel = policyLogger.getLevel();
policyLogger.setLevel(Level.WARN);
logs = new MemoryAppender();
policyLogger.addAppender(logs);
}
@AfterMethod(groups = "short", alwaysRun = true)
public void tearDown() {
policyLogger.setLevel(originalLevel);
policyLogger.removeAppender(logs);
}
/**
* Ensures that when used {@link RoundRobinPolicy} properly round robins requests within
* nodes in a single datacenter.
*
* @test_category load_balancing:round_robin
*/
@Test(groups = "short")
public void should_round_robin_within_single_datacenter() {
// given: a 5 node cluster using RoundRobinPolicy.
ScassandraCluster sCluster = ScassandraCluster.builder().withNodes(5).build();
Cluster cluster = Cluster.builder()
.addContactPoints(sCluster.address(1).getAddress())
.withPort(sCluster.getBinaryPort())
.withLoadBalancingPolicy(new RoundRobinPolicy())
.withNettyOptions(nonQuietClusterCloseOptions)
.build();
try {
sCluster.init();
Session session = cluster.connect();
// when: a query is executed 50 times.
queryTracker.query(session, 50);
// then: all nodes should be queried equally.
for (int i = 1; i <= 5; i++) {
queryTracker.assertQueried(sCluster, 1, i, 10);
}
} finally {
cluster.close();
sCluster.stop();
}
}
/**
* Ensures that when used {@link RoundRobinPolicy} properly round robins requests to nodes irrespective
* of cluster topology by ensuring nodes in different data centers are queried equally to others.
*
* @test_category load_balancing:round_robin
*/
@Test(groups = "short")
public void should_round_robin_irrespective_of_topology() {
// given: a 10 node, 5 DC cluster using RoundRobinPolicy.
ScassandraCluster sCluster = ScassandraCluster.builder().withNodes(2, 2, 2, 2, 2).build();
Cluster cluster = Cluster.builder()
.addContactPoints(sCluster.address(1).getAddress())
.withPort(sCluster.getBinaryPort())
.withLoadBalancingPolicy(new RoundRobinPolicy())
.withNettyOptions(nonQuietClusterCloseOptions)
.build();
try {
sCluster.init();
Session session = cluster.connect();
// when: a query is executed 50 times.
queryTracker.query(session, 50);
// then: all nodes should be queried equally.
for (int dc = 1; dc <= 5; dc++) {
for (int i = 1; i <= 2; i++) {
queryTracker.assertQueried(sCluster, dc, i, 5);
}
}
} finally {
cluster.close();
sCluster.stop();
}
}
/**
* Ensures that when used {@link RoundRobinPolicy} generates a warning if a consistency level is used
* that is data center local (i.e. LOCAL_QUORUM) and nodes from multiple data centers are in the cluster
* and that warning is only generated once. Also validates that is a non-Dc local consistency level is
* used (i.e. ONE) that no such warning is generated.
*
* @test_category load_balancing:round_robin
*/
@Test(groups = "short", dataProvider = "consistencyLevels", dataProviderClass = DataProviders.class)
public void should_warn_if_using_dc_local_consistency_level(ConsistencyLevel cl) {
// given: a 2 node, 2 DC cluster using RoundRobinPolicy.
ScassandraCluster sCluster = ScassandraCluster.builder().withNodes(1, 1).build();
Cluster cluster = Cluster.builder()
.addContactPoints(sCluster.address(1).getAddress())
.withPort(sCluster.getBinaryPort())
.withLoadBalancingPolicy(new RoundRobinPolicy())
.withNettyOptions(nonQuietClusterCloseOptions)
.build();
String expectedLogMessage = "Detected request at Consistency Level " + cl + " but the non-DC aware RoundRobinPolicy is in use.";
try {
sCluster.init();
Session session = cluster.connect();
// when: a query is executed 50 times.
queryTracker.query(session, 50, cl);
// then: all nodes should be queried equally.
queryTracker.assertQueried(sCluster, 1, 1, 25);
queryTracker.assertQueried(sCluster, 2, 1, 25);
// Should get a warning if using a local DC cl.
if (cl.isDCLocal()) {
assertThat(logs.get()).containsOnlyOnce(expectedLogMessage);
} else {
assertThat(logs.get()).doesNotContain(expectedLogMessage);
}
} finally {
cluster.close();
sCluster.stop();
}
}
}