public virtual void TestCorruptBlockRereplicatedAcrossRacks()
{
Configuration conf = GetConf();
short ReplicationFactor = 2;
int fileLen = 512;
Path filePath = new Path("/testFile");
// Datanodes are spread across two racks
string[] racks = new string[] { "/rack1", "/rack1", "/rack2", "/rack2" };
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).NumDataNodes(racks.Length
).Racks(racks).Build();
FSNamesystem ns = cluster.GetNameNode().GetNamesystem();
try
{
// Create a file with one block with a replication factor of 2
FileSystem fs = cluster.GetFileSystem();
DFSTestUtil.CreateFile(fs, filePath, fileLen, ReplicationFactor, 1L);
string fileContent = DFSTestUtil.ReadFile(fs, filePath);
ExtendedBlock b = DFSTestUtil.GetFirstBlock(fs, filePath);
DFSTestUtil.WaitForReplication(cluster, b, 2, ReplicationFactor, 0);
// Corrupt a replica of the block
int dnToCorrupt = DFSTestUtil.FirstDnWithBlock(cluster, b);
NUnit.Framework.Assert.IsTrue(cluster.CorruptReplica(dnToCorrupt, b));
// Restart the datanode so blocks are re-scanned, and the corrupt
// block is detected.
cluster.RestartDataNode(dnToCorrupt);
// Wait for the namenode to notice the corrupt replica
DFSTestUtil.WaitCorruptReplicas(fs, ns, filePath, b, 1);
// The rack policy is still respected
DFSTestUtil.WaitForReplication(cluster, b, 2, ReplicationFactor, 0);
// Ensure all replicas are valid (the corrupt replica may not
// have been cleaned up yet).
for (int i = 0; i < racks.Length; i++)
{
string blockContent = cluster.ReadBlockOnDataNode(i, b);
if (blockContent != null && i != dnToCorrupt)
{
NUnit.Framework.Assert.AreEqual("Corrupt replica", fileContent, blockContent);
}
}
}
finally
{
cluster.Shutdown();
}
}