HDFS-4261. Fix bugs in Balancer that it does not terminate in some cases and it checks BlockPlacementPolicy instance incorrectly. Contributed by Junping Du

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1419192 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Tsz-wo Sze 2012-12-10 03:31:34 +00:00
parent bcaba93941
commit 8f5bd5f1bc
4 changed files with 84 additions and 13 deletions

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@ -269,6 +269,10 @@ Trunk (Unreleased)
HDFS-4260 Fix HDFS tests to set test dir to a valid HDFS path as opposed
to the local build path (Chri Nauroth via Sanjay)
HDFS-4261. Fix bugs in Balancer that it does not terminate in some cases
and it checks BlockPlacementPolicy instance incorrectly. (Junping Du via
szetszwo)
Release 2.0.3-alpha - Unreleased
INCOMPATIBLE CHANGES

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@ -224,7 +224,6 @@ public class Balancer {
= new HashMap<String, BalancerDatanode>();
private NetworkTopology cluster;
final static private int MOVER_THREAD_POOL_SIZE = 1000;
final private ExecutorService moverExecutor =
Executors.newFixedThreadPool(MOVER_THREAD_POOL_SIZE);
@ -801,8 +800,8 @@ private void dispatchBlocks() {
*/
private static void checkReplicationPolicyCompatibility(Configuration conf
) throws UnsupportedActionException {
if (BlockPlacementPolicy.getInstance(conf, null, null) instanceof
BlockPlacementPolicyDefault) {
if (!(BlockPlacementPolicy.getInstance(conf, null, null) instanceof
BlockPlacementPolicyDefault)) {
throw new UnsupportedActionException(
"Balancer without BlockPlacementPolicyDefault");
}
@ -1085,7 +1084,6 @@ private long get() {
}
};
private BytesMoved bytesMoved = new BytesMoved();
private int notChangedIterations = 0;
/* Start a thread to dispatch block moves for each source.
* The thread selects blocks to move & sends request to proxy source to
@ -1384,16 +1382,9 @@ private ReturnStatus run(int iteration, Formatter formatter,
* available to move.
* Exit no byte has been moved for 5 consecutive iterations.
*/
if (dispatchBlockMoves() > 0) {
notChangedIterations = 0;
} else {
notChangedIterations++;
if (notChangedIterations >= 5) {
System.out.println(
"No block has been moved for 5 iterations. Exiting...");
if (!this.nnc.shouldContinue(dispatchBlockMoves())) {
return ReturnStatus.NO_MOVE_PROGRESS;
}
}
// clean all lists
resetData(conf);

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@ -52,6 +52,7 @@
class NameNodeConnector {
private static final Log LOG = Balancer.LOG;
private static final Path BALANCER_ID_PATH = new Path("/system/balancer.id");
private static final int MAX_NOT_CHANGED_INTERATIONS = 5;
final URI nameNodeUri;
final String blockpoolID;
@ -65,6 +66,8 @@ class NameNodeConnector {
private final boolean encryptDataTransfer;
private boolean shouldRun;
private long keyUpdaterInterval;
// used for balancer
private int notChangedIterations = 0;
private BlockTokenSecretManager blockTokenSecretManager;
private Daemon keyupdaterthread; // AccessKeyUpdater thread
private DataEncryptionKey encryptionKey;
@ -119,6 +122,20 @@ class NameNodeConnector {
}
}
boolean shouldContinue(long dispatchBlockMoveBytes) {
if (dispatchBlockMoveBytes > 0) {
notChangedIterations = 0;
} else {
notChangedIterations++;
if (notChangedIterations >= MAX_NOT_CHANGED_INTERATIONS) {
System.out.println("No block has been moved for "
+ notChangedIterations + " iterations. Exiting...");
return false;
}
}
return true;
}
/** Get an access token for a block. */
Token<BlockTokenIdentifier> getAccessToken(ExtendedBlock eb
) throws IOException {

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@ -41,6 +41,7 @@
import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
import org.apache.hadoop.net.NetworkTopology;
import org.junit.Test;
import junit.framework.Assert;
/**
* This class tests if a balancer schedules tasks correctly.
@ -175,6 +176,19 @@ private void runBalancer(Configuration conf,
waitForBalancer(totalUsedSpace, totalCapacity);
}
private void runBalancerCanFinish(Configuration conf,
long totalUsedSpace, long totalCapacity) throws Exception {
waitForHeartBeat(totalUsedSpace, totalCapacity);
// start rebalancing
Collection<URI> namenodes = DFSUtil.getNsServiceRpcUris(conf);
final int r = Balancer.run(namenodes, Balancer.Parameters.DEFALUT, conf);
Assert.assertTrue(r == Balancer.ReturnStatus.SUCCESS.code ||
(r == Balancer.ReturnStatus.NO_MOVE_PROGRESS.code));
waitForHeartBeat(totalUsedSpace, totalCapacity);
LOG.info("Rebalancing with default factor.");
}
/**
* Create a cluster with even distribution, and a new empty node is added to
* the cluster, then test rack locality for balancer policy.
@ -289,4 +303,49 @@ public void testBalancerWithNodeGroup() throws Exception {
cluster.shutdown();
}
}
/**
* Create a 4 nodes cluster: 2 nodes (n0, n1) in RACK0/NODEGROUP0, 1 node (n2)
* in RACK1/NODEGROUP1 and 1 node (n3) in RACK1/NODEGROUP2. Fill the cluster
* to 60% and 3 replicas, so n2 and n3 will have replica for all blocks according
* to replica placement policy with NodeGroup. As a result, n2 and n3 will be
* filled with 80% (60% x 4 / 3), and no blocks can be migrated from n2 and n3
* to n0 or n1 as balancer policy with node group. Thus, we expect the balancer
* to end in 5 iterations without move block process.
*/
@Test
public void testBalancerEndInNoMoveProgress() throws Exception {
Configuration conf = createConf();
long[] capacities = new long[]{CAPACITY, CAPACITY, CAPACITY, CAPACITY};
String[] racks = new String[]{RACK0, RACK0, RACK1, RACK1};
String[] nodeGroups = new String[]{NODEGROUP0, NODEGROUP0, NODEGROUP1, NODEGROUP2};
int numOfDatanodes = capacities.length;
assertEquals(numOfDatanodes, racks.length);
assertEquals(numOfDatanodes, nodeGroups.length);
MiniDFSCluster.Builder builder = new MiniDFSCluster.Builder(conf)
.numDataNodes(capacities.length)
.racks(racks)
.simulatedCapacities(capacities);
MiniDFSClusterWithNodeGroup.setNodeGroups(nodeGroups);
cluster = new MiniDFSClusterWithNodeGroup(builder);
try {
cluster.waitActive();
client = NameNodeProxies.createProxy(conf,
cluster.getFileSystem(0).getUri(),
ClientProtocol.class).getProxy();
long totalCapacity = TestBalancer.sum(capacities);
// fill up the cluster to be 60% full
long totalUsedSpace = totalCapacity * 6 / 10;
TestBalancer.createFile(cluster, filePath, totalUsedSpace / 3,
(short) (3), 0);
// run balancer which can finish in 5 iterations with no block movement.
runBalancerCanFinish(conf, totalUsedSpace, totalCapacity);
} finally {
cluster.shutdown();
}
}
}