static DatanodeInfo chooseDatanode(
final NameNode namenode,
final String path,
final HttpOpParam.Op op,
final long openOffset,
final long blocksize,
Configuration conf)
throws IOException {
final BlockManager bm = namenode.getNamesystem().getBlockManager();
if (op == PutOpParam.Op.CREATE) {
// choose a datanode near to client
final DatanodeDescriptor clientNode =
bm.getDatanodeManager().getDatanodeByHost(getRemoteAddress());
if (clientNode != null) {
final DatanodeDescriptor[] datanodes =
bm.getBlockPlacementPolicy().chooseTarget(path, 1, clientNode, null, blocksize);
if (datanodes.length > 0) {
return datanodes[0];
}
}
} else if (op == GetOpParam.Op.OPEN
|| op == GetOpParam.Op.GETFILECHECKSUM
|| op == PostOpParam.Op.APPEND) {
// choose a datanode containing a replica
final NamenodeProtocols np = namenode.getRpcServer();
final HdfsFileStatus status = np.getFileInfo(path);
if (status == null) {
throw new FileNotFoundException("File " + path + " not found.");
}
final long len = status.getLen();
if (op == GetOpParam.Op.OPEN) {
if (openOffset < 0L || (openOffset >= len && len > 0)) {
throw new IOException(
"Offset="
+ openOffset
+ " out of the range [0, "
+ len
+ "); "
+ op
+ ", path="
+ path);
}
}
if (len > 0) {
final long offset = op == GetOpParam.Op.OPEN ? openOffset : len - 1;
final LocatedBlocks locations = np.getBlockLocations(path, offset, 1);
final int count = locations.locatedBlockCount();
if (count > 0) {
return JspHelper.bestNode(locations.get(0).getLocations(), false, conf);
}
}
}
return (DatanodeDescriptor)
bm.getDatanodeManager().getNetworkTopology().chooseRandom(NodeBase.ROOT);
}
/**
* Setup a {@link MiniDFSCluster}. Create a block with both {@link State#NORMAL} and {@link
* State#READ_ONLY_SHARED} replicas.
*/
@Before
public void setup() throws IOException, InterruptedException {
conf = new HdfsConfiguration();
SimulatedFSDataset.setFactory(conf);
Configuration[] overlays = new Configuration[NUM_DATANODES];
for (int i = 0; i < overlays.length; i++) {
overlays[i] = new Configuration();
if (i == RO_NODE_INDEX) {
overlays[i].setEnum(
SimulatedFSDataset.CONFIG_PROPERTY_STATE,
i == RO_NODE_INDEX ? READ_ONLY_SHARED : NORMAL);
}
}
cluster =
new MiniDFSCluster.Builder(conf)
.numDataNodes(NUM_DATANODES)
.dataNodeConfOverlays(overlays)
.build();
fs = cluster.getFileSystem();
blockManager = cluster.getNameNode().getNamesystem().getBlockManager();
datanodeManager = blockManager.getDatanodeManager();
client =
new DFSClient(
new InetSocketAddress("localhost", cluster.getNameNodePort()),
cluster.getConfiguration(0));
for (int i = 0; i < NUM_DATANODES; i++) {
DataNode dataNode = cluster.getDataNodes().get(i);
validateStorageState(
BlockManagerTestUtil.getStorageReportsForDatanode(
datanodeManager.getDatanode(dataNode.getDatanodeId())),
i == RO_NODE_INDEX ? READ_ONLY_SHARED : NORMAL);
}
// Create a 1 block file
DFSTestUtil.createFile(fs, PATH, BLOCK_SIZE, BLOCK_SIZE, BLOCK_SIZE, (short) 1, seed);
LocatedBlock locatedBlock = getLocatedBlock();
extendedBlock = locatedBlock.getBlock();
block = extendedBlock.getLocalBlock();
assertThat(locatedBlock.getLocations().length, is(1));
normalDataNode = locatedBlock.getLocations()[0];
readOnlyDataNode =
datanodeManager.getDatanode(cluster.getDataNodes().get(RO_NODE_INDEX).getDatanodeId());
assertThat(normalDataNode, is(not(readOnlyDataNode)));
validateNumberReplicas(1);
// Inject the block into the datanode with READ_ONLY_SHARED storage
cluster.injectBlocks(0, RO_NODE_INDEX, Collections.singleton(block));
// There should now be 2 *locations* for the block
// Must wait until the NameNode has processed the block report for the injected blocks
waitForLocations(2);
}
