package org.apache.hadoop.dfs;
import java.io.File;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.dfs.DFSTestUtil;
import org.apache.hadoop.dfs.MiniDFSCluster;
import org.apache.hadoop.dfs.TestDatanodeBlockScanner;
import org.apache.hadoop.dfs.Block;
import org.apache.hadoop.dfs.DatanodeID;
import junit.framework.TestCase;
public class TestOverReplicatedBlocks extends TestCase {
/** Test processOverReplicatedBlock can handle corrupt replicas fine.
* It make sure that it won't treat corrupt replicas as valid ones
* thus prevents NN deleting valid replicas but keeping
* corrupt ones.
*/
public void testProcesOverReplicateBlock() throws IOException {
Configuration conf = new Configuration();
conf.setLong("dfs.blockreport.intervalMsec", 1000L);
conf.set("dfs.replication.pending.timeout.sec", Integer.toString(2));
MiniDFSCluster cluster = new MiniDFSCluster(conf, 3, true, null);
FileSystem fs = cluster.getFileSystem();
try {
final Path fileName = new Path("/foo1");
DFSTestUtil.createFile(fs, fileName, 2, (short)3, 0L);
DFSTestUtil.waitReplication(fs, fileName, (short)3);
// corrupt the block on datanode 0
Block block = DFSTestUtil.getFirstBlock(fs, fileName);
TestDatanodeBlockScanner.corruptReplica(block.getBlockName(), 0);
File scanLog = new File(System.getProperty("test.build.data"),
"dfs/data/data1/current/dncp_block_verification.log.curr");
assertTrue(scanLog.delete());
// restart the datanode so the corrupt replica will be detected
cluster.restartDataNode(0);
DFSTestUtil.waitReplication(fs, fileName, (short)2);
final DatanodeID corruptDataNode =
cluster.getDataNodes().get(2).dnRegistration;
final FSNamesystem namesystem = FSNamesystem.getFSNamesystem();
synchronized (namesystem.heartbeats) {
// set live datanode's remaining space to be 0
// so they will be chosen to be deleted when over-replication occurs
for (DatanodeDescriptor datanode : namesystem.heartbeats) {
if (!corruptDataNode.equals(datanode)) {
datanode.updateHeartbeat(100L, 100L, 0L, 0);
}
}
// decrease the replication factor to 1;
namesystem.setReplication(fileName.toString(), (short)1);
// corrupt one won't be chosen to be excess one
// without 4910 the number of live replicas would be 0: block gets lost
assertEquals(1, namesystem.countNodes(block).liveReplicas());
}
} finally {
cluster.shutdown();
}
}
}