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// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.vespa.zookeeper;
import com.yahoo.cloud.config.ZookeeperServerConfig;
import com.yahoo.net.HostName;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;
import java.io.File;
import java.io.IOException;
import java.nio.file.Path;
import java.util.stream.IntStream;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;
/**
* Tests dynamic reconfiguration of zookeeper cluster.
*
* @author hmusum
*/
public class ReconfigurerTest {
private File cfgFile;
private File idFile;
private TestableReconfigurer reconfigurer;
@Rule
public TemporaryFolder folder = new TemporaryFolder();
@Before
public void setup() throws IOException {
cfgFile = folder.newFile();
idFile = folder.newFile("myid");
reconfigurer = new TestableReconfigurer(new TestableVespaZooKeeperAdmin());
}
@Test
public void testReconfigure() {
ZookeeperServerConfig initialConfig = createConfig(3, true);
reconfigurer.startOrReconfigure(initialConfig);
assertSame(initialConfig, reconfigurer.activeConfig());
// Cluster grows
ZookeeperServerConfig nextConfig = createConfig(5, true);
reconfigurer.startOrReconfigure(nextConfig);
assertEquals("node1:2181", reconfigurer.connectionSpec());
assertEquals("3=node3:2182:2183;2181,4=node4:2182:2183;2181", reconfigurer.joiningServers());
assertNull("No servers are leaving", reconfigurer.leavingServers());
assertEquals(1, reconfigurer.reconfigurations());
assertSame(nextConfig, reconfigurer.activeConfig());
// No reconfiguration happens with same config
reconfigurer.startOrReconfigure(nextConfig);
assertEquals(1, reconfigurer.reconfigurations());
assertSame(nextConfig, reconfigurer.activeConfig());
// Cluster shrinks
nextConfig = createConfig(3, true);
reconfigurer.startOrReconfigure(nextConfig);
assertEquals(2, reconfigurer.reconfigurations());
assertEquals("node1:2181", reconfigurer.connectionSpec());
assertNull("No servers are joining", reconfigurer.joiningServers());
assertEquals("3,4", reconfigurer.leavingServers());
assertSame(nextConfig, reconfigurer.activeConfig());
}
@Test
public void testReconfigureFailsWithReconfigInProgressThenSucceeds() {
reconfigurer = new TestableReconfigurer(new TemporarilyFailVespaZooKeeperAdmin());
ZookeeperServerConfig initialConfig = createConfig(3, true);
reconfigurer.startOrReconfigure(initialConfig);
assertSame(initialConfig, reconfigurer.activeConfig());
ZookeeperServerConfig nextConfig = createConfig(5, true);
reconfigurer.startOrReconfigure(nextConfig);
assertEquals("node1:2181", reconfigurer.connectionSpec());
assertEquals("3=node3:2182:2183;2181,4=node4:2182:2183;2181", reconfigurer.joiningServers());
assertNull("No servers are leaving", reconfigurer.leavingServers());
assertEquals(1, reconfigurer.reconfigurations());
assertSame(nextConfig, reconfigurer.activeConfig());
}
@Test
public void testDynamicReconfigurationDisabled() {
ZookeeperServerConfig initialConfig = createConfig(3, false);
reconfigurer.startOrReconfigure(initialConfig);
assertSame(initialConfig, reconfigurer.activeConfig());
ZookeeperServerConfig nextConfig = createConfig(5, false);
reconfigurer.startOrReconfigure(nextConfig);
assertSame(initialConfig, reconfigurer.activeConfig());
assertEquals(0, reconfigurer.reconfigurations());
}
@After
public void stopReconfigurer() {
reconfigurer.shutdown();
}
private ZookeeperServerConfig createConfig(int numberOfServers, boolean dynamicReconfiguration) {
ZookeeperServerConfig.Builder builder = new ZookeeperServerConfig.Builder();
builder.zooKeeperConfigFile(cfgFile.getAbsolutePath());
builder.myidFile(idFile.getAbsolutePath());
IntStream.range(0, numberOfServers).forEach(i -> builder.server(newServer(i, "node" + i)));
builder.myid(0);
builder.dynamicReconfiguration(dynamicReconfiguration);
return builder.build();
}
private ZookeeperServerConfig.Server.Builder newServer(int id, String hostName) {
ZookeeperServerConfig.Server.Builder builder = new ZookeeperServerConfig.Server.Builder();
builder.id(id);
builder.hostname(hostName);
return builder;
}
private static class TestableReconfigurer extends Reconfigurer implements VespaZooKeeperServer{
private final TestableVespaZooKeeperAdmin zkReconfigurer;
TestableReconfigurer(TestableVespaZooKeeperAdmin zkReconfigurer) {
super(zkReconfigurer);
this.zkReconfigurer = zkReconfigurer;
HostName.setHostNameForTestingOnly("node1");
}
void startOrReconfigure(ZookeeperServerConfig newConfig) {
startOrReconfigure(newConfig, this);
}
@Override
void startOrReconfigure(ZookeeperServerConfig newConfig, VespaZooKeeperServer server) {
super.startOrReconfigure(newConfig, l -> {}, this);
}
String connectionSpec() {
return zkReconfigurer.connectionSpec;
}
String joiningServers() {
return zkReconfigurer.joiningServers;
}
String leavingServers() {
return zkReconfigurer.leavingServers;
}
int reconfigurations() {
return zkReconfigurer.reconfigurations;
}
@Override
public void start(Path configFilePath) { }
}
private static class TestableVespaZooKeeperAdmin implements VespaZooKeeperAdmin {
String connectionSpec;
String joiningServers;
String leavingServers;
int reconfigurations = 0;
@Override
public void reconfigure(String connectionSpec, String joiningServers, String leavingServers) throws ReconfigException {
this.connectionSpec = connectionSpec;
this.joiningServers = joiningServers;
this.leavingServers = leavingServers;
this.reconfigurations++;
}
}
// Fails 3 times with KeeperException.ReconfigInProgress(), then succeeds
private static class TemporarilyFailVespaZooKeeperAdmin extends TestableVespaZooKeeperAdmin {
private int attempts = 0;
public void reconfigure(String connectionSpec, String joiningServers, String leavingServers) throws ReconfigException {
if (++attempts < 3)
throw new ReconfigException("Reconfig failed");
else
super.reconfigure(connectionSpec, joiningServers, leavingServers);
}
}
}
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