/**
* 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.hdfs.server.balancer;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.impl.Log4JLogger;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSTestUtil;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
import org.apache.hadoop.hdfs.server.namenode.LeaseManager;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.log4j.Level;
import org.junit.Assert;
import org.junit.Test;
/**
* Test balancer with multiple NameNodes
*/
public class TestBalancerWithMultipleNameNodes {
static final Log LOG = Balancer.LOG;
{
((Log4JLogger)LOG).getLogger().setLevel(Level.ALL);
((Log4JLogger)NameNode.stateChangeLog).getLogger().setLevel(Level.OFF);
((Log4JLogger)LeaseManager.LOG).getLogger().setLevel(Level.OFF);
((Log4JLogger)LogFactory.getLog(FSNamesystem.class)).getLogger().setLevel(Level.OFF);
}
private static final long CAPACITY = 500L;
private static final String RACK0 = "/rack0";
private static final String RACK1 = "/rack1";
private static final String FILE_NAME = "/tmp.txt";
private static final Path FILE_PATH = new Path(FILE_NAME);
private static final Random RANDOM = new Random();
static {
Balancer.setBlockMoveWaitTime(1000L) ;
}
/** Common objects used in various methods. */
private static class Suite {
final Configuration conf;
final MiniDFSCluster cluster;
final ClientProtocol[] clients;
final short replication;
Suite(MiniDFSCluster cluster, final int nNameNodes, final int nDataNodes,
Configuration conf) throws IOException {
this.conf = conf;
this.cluster = cluster;
clients = new ClientProtocol[nNameNodes];
for(int i = 0; i < nNameNodes; i++) {
clients[i] = cluster.getNameNode(i).getRpcServer();
}
replication = (short)Math.max(1, nDataNodes - 1);
}
}
/* create a file with a length of <code>fileLen</code> */
private static void createFile(Suite s, int index, long len
) throws IOException {
final FileSystem fs = s.cluster.getFileSystem(index);
DFSTestUtil.createFile(fs, FILE_PATH, len, s.replication, RANDOM.nextLong());
DFSTestUtil.waitReplication(fs, FILE_PATH, s.replication);
}
/* fill up a cluster with <code>numNodes</code> datanodes
* whose used space to be <code>size</code>
*/
private static ExtendedBlock[][] generateBlocks(Suite s, long size
) throws IOException {
final ExtendedBlock[][] blocks = new ExtendedBlock[s.clients.length][];
for(int n = 0; n < s.clients.length; n++) {
final long fileLen = size/s.replication;
createFile(s, n, fileLen);
final List<LocatedBlock> locatedBlocks = s.clients[n].getBlockLocations(
FILE_NAME, 0, fileLen).getLocatedBlocks();
final int numOfBlocks = locatedBlocks.size();
blocks[n] = new ExtendedBlock[numOfBlocks];
for(int i = 0; i < numOfBlocks; i++) {
final ExtendedBlock b = locatedBlocks.get(i).getBlock();
blocks[n][i] = new ExtendedBlock(b.getBlockPoolId(), b.getBlockId(),
b.getNumBytes(), b.getGenerationStamp());
}
}
return blocks;
}
/* wait for one heartbeat */
static void wait(final ClientProtocol[] clients,
long expectedUsedSpace, long expectedTotalSpace) throws IOException {
LOG.info("WAIT expectedUsedSpace=" + expectedUsedSpace
+ ", expectedTotalSpace=" + expectedTotalSpace);
for(int n = 0; n < clients.length; n++) {
int i = 0;
for(boolean done = false; !done; ) {
final long[] s = clients[n].getStats();
done = s[0] == expectedTotalSpace && s[1] == expectedUsedSpace;
if (!done) {
sleep(100L);
if (++i % 100 == 0) {
LOG.warn("WAIT i=" + i + ", s=[" + s[0] + ", " + s[1] + "]");
}
}
}
}
}
static void runBalancer(Suite s,
final long totalUsed, final long totalCapacity) throws Exception {
final double avg = totalUsed*100.0/totalCapacity;
LOG.info("BALANCER 0: totalUsed=" + totalUsed
+ ", totalCapacity=" + totalCapacity
+ ", avg=" + avg);
wait(s.clients, totalUsed, totalCapacity);
LOG.info("BALANCER 1");
// start rebalancing
final List<InetSocketAddress> namenodes = DFSUtil.getNNServiceRpcAddresses(s.conf);
final int r = Balancer.run(namenodes, Balancer.Parameters.DEFALUT, s.conf);
Assert.assertEquals(Balancer.ReturnStatus.SUCCESS.code, r);
LOG.info("BALANCER 2");
wait(s.clients, totalUsed, totalCapacity);
LOG.info("BALANCER 3");
int i = 0;
for(boolean balanced = false; !balanced; i++) {
final long[] used = new long[s.cluster.getDataNodes().size()];
final long[] cap = new long[used.length];
for(int n = 0; n < s.clients.length; n++) {
final DatanodeInfo[] datanodes = s.clients[n].getDatanodeReport(
DatanodeReportType.ALL);
Assert.assertEquals(datanodes.length, used.length);
for(int d = 0; d < datanodes.length; d++) {
if (n == 0) {
used[d] = datanodes[d].getDfsUsed();
cap[d] = datanodes[d].getCapacity();
if (i % 100 == 0) {
LOG.warn("datanodes[" + d
+ "]: getDfsUsed()=" + datanodes[d].getDfsUsed()
+ ", getCapacity()=" + datanodes[d].getCapacity());
}
} else {
Assert.assertEquals(used[d], datanodes[d].getDfsUsed());
Assert.assertEquals(cap[d], datanodes[d].getCapacity());
}
}
}
balanced = true;
for(int d = 0; d < used.length; d++) {
final double p = used[d]*100.0/cap[d];
balanced = p <= avg + Balancer.Parameters.DEFALUT.threshold;
if (!balanced) {
if (i % 100 == 0) {
LOG.warn("datanodes " + d + " is not yet balanced: "
+ "used=" + used[d] + ", cap=" + cap[d] + ", avg=" + avg);
LOG.warn("TestBalancer.sum(used)=" + TestBalancer.sum(used)
+ ", TestBalancer.sum(cap)=" + TestBalancer.sum(cap));
}
sleep(100);
break;
}
}
}
LOG.info("BALANCER 6");
}
private static void sleep(long ms) {
try {
Thread.sleep(ms);
} catch(InterruptedException e) {
LOG.error(e);
}
}
private static Configuration createConf() {
final Configuration conf = new HdfsConfiguration();
TestBalancer.initConf(conf);
return conf;
}
/**
* First start a cluster and fill the cluster up to a certain size.
* Then redistribute blocks according the required distribution.
* Finally, balance the cluster.
*
* @param nNameNodes Number of NameNodes
* @param distributionPerNN The distribution for each NameNode.
* @param capacities Capacities of the datanodes
* @param racks Rack names
* @param conf Configuration
*/
private void unevenDistribution(final int nNameNodes,
long distributionPerNN[], long capacities[], String[] racks,
Configuration conf) throws Exception {
LOG.info("UNEVEN 0");
final int nDataNodes = distributionPerNN.length;
if (capacities.length != nDataNodes || racks.length != nDataNodes) {
throw new IllegalArgumentException("Array length is not the same");
}
// calculate total space that need to be filled
final long usedSpacePerNN = TestBalancer.sum(distributionPerNN);
// fill the cluster
final ExtendedBlock[][] blocks;
{
LOG.info("UNEVEN 1");
final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
.numNameNodes(nNameNodes)
.numDataNodes(nDataNodes)
.racks(racks)
.simulatedCapacities(capacities)
.build();
LOG.info("UNEVEN 2");
try {
cluster.waitActive();
LOG.info("UNEVEN 3");
final Suite s = new Suite(cluster, nNameNodes, nDataNodes, conf);
blocks = generateBlocks(s, usedSpacePerNN);
LOG.info("UNEVEN 4");
} finally {
cluster.shutdown();
}
}
conf.set(DFSConfigKeys.DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_KEY, "0.0f");
{
LOG.info("UNEVEN 10");
final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
.numNameNodes(nNameNodes)
.numDataNodes(nDataNodes)
.racks(racks)
.simulatedCapacities(capacities)
.format(false)
.build();
LOG.info("UNEVEN 11");
try {
cluster.waitActive();
LOG.info("UNEVEN 12");
final Suite s = new Suite(cluster, nNameNodes, nDataNodes, conf);
for(int n = 0; n < nNameNodes; n++) {
// redistribute blocks
final Block[][] blocksDN = TestBalancer.distributeBlocks(
blocks[n], s.replication, distributionPerNN);
for(int d = 0; d < blocksDN.length; d++)
cluster.injectBlocks(n, d, Arrays.asList(blocksDN[d]));
LOG.info("UNEVEN 13: n=" + n);
}
final long totalCapacity = TestBalancer.sum(capacities);
final long totalUsed = nNameNodes*usedSpacePerNN;
LOG.info("UNEVEN 14");
runBalancer(s, totalUsed, totalCapacity);
LOG.info("UNEVEN 15");
} finally {
cluster.shutdown();
}
LOG.info("UNEVEN 16");
}
}
/**
* This test start a cluster, fill the DataNodes to be 30% full;
* It then adds an empty node and start balancing.
*
* @param nNameNodes Number of NameNodes
* @param capacities Capacities of the datanodes
* @param racks Rack names
* @param newCapacity the capacity of the new DataNode
* @param newRack the rack for the new DataNode
* @param conf Configuration
*/
private void runTest(final int nNameNodes, long[] capacities, String[] racks,
long newCapacity, String newRack, Configuration conf) throws Exception {
final int nDataNodes = capacities.length;
LOG.info("nNameNodes=" + nNameNodes + ", nDataNodes=" + nDataNodes);
Assert.assertEquals(nDataNodes, racks.length);
LOG.info("RUN_TEST -1");
final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
.numNameNodes(nNameNodes)
.numDataNodes(nDataNodes)
.racks(racks)
.simulatedCapacities(capacities)
.build();
LOG.info("RUN_TEST 0");
try {
cluster.waitActive();
LOG.info("RUN_TEST 1");
final Suite s = new Suite(cluster, nNameNodes, nDataNodes, conf);
long totalCapacity = TestBalancer.sum(capacities);
LOG.info("RUN_TEST 2");
// fill up the cluster to be 30% full
final long totalUsed = totalCapacity*3/10;
final long size = (totalUsed/nNameNodes)/s.replication;
for(int n = 0; n < nNameNodes; n++) {
createFile(s, n, size);
}
LOG.info("RUN_TEST 3");
// start up an empty node with the same capacity and on the same rack
cluster.startDataNodes(conf, 1, true, null,
new String[]{newRack}, new long[]{newCapacity});
totalCapacity += newCapacity;
LOG.info("RUN_TEST 4");
// run RUN_TEST and validate results
runBalancer(s, totalUsed, totalCapacity);
LOG.info("RUN_TEST 5");
} finally {
cluster.shutdown();
}
LOG.info("RUN_TEST 6");
}
/** Test a cluster with even distribution,
* then a new empty node is added to the cluster
*/
@Test
public void testBalancer() throws Exception {
final Configuration conf = createConf();
runTest(2, new long[]{CAPACITY}, new String[]{RACK0},
CAPACITY/2, RACK0, conf);
}
/** Test unevenly distributed cluster */
@Test
public void testUnevenDistribution() throws Exception {
final Configuration conf = createConf();
unevenDistribution(2,
new long[] {30*CAPACITY/100, 5*CAPACITY/100},
new long[]{CAPACITY, CAPACITY},
new String[] {RACK0, RACK1},
conf);
}
}