| /** |
| * 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.datanode.erasurecode; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.ChecksumException; |
| import org.apache.hadoop.fs.StorageType; |
| import org.apache.hadoop.hdfs.BlockReader; |
| import org.apache.hadoop.hdfs.DFSUtilClient; |
| import org.apache.hadoop.hdfs.DFSUtilClient.CorruptedBlocks; |
| import org.apache.hadoop.hdfs.client.impl.BlockReaderRemote; |
| import org.apache.hadoop.hdfs.net.Peer; |
| import org.apache.hadoop.hdfs.protocol.DatanodeID; |
| import org.apache.hadoop.hdfs.protocol.DatanodeInfo; |
| import org.apache.hadoop.hdfs.protocol.ExtendedBlock; |
| import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier; |
| import org.apache.hadoop.hdfs.server.datanode.DataNode; |
| import org.apache.hadoop.hdfs.server.datanode.DataNodeFaultInjector; |
| import org.apache.hadoop.hdfs.util.StripedBlockUtil.BlockReadStats; |
| import org.apache.hadoop.io.IOUtils; |
| import org.apache.hadoop.net.NetUtils; |
| import org.apache.hadoop.security.token.Token; |
| import org.slf4j.Logger; |
| |
| import java.io.IOException; |
| import java.net.InetSocketAddress; |
| import java.net.Socket; |
| import java.nio.ByteBuffer; |
| import java.util.EnumSet; |
| import java.util.concurrent.Callable; |
| |
| /** |
| * StripedBlockReader is used to read block data from one source DN, it contains |
| * a block reader, read buffer and striped block index. |
| * Only allocate StripedBlockReader once for one source, and the StripedReader |
| * has the same array order with sources. Typically we only need to allocate |
| * minimum number (minRequiredSources) of StripedReader, and allocate |
| * new for new source DN if some existing DN invalid or slow. |
| * If some source DN is corrupt, set the corresponding blockReader to |
| * null and will never read from it again. |
| */ |
| @InterfaceAudience.Private |
| class StripedBlockReader { |
| private static final Logger LOG = DataNode.LOG; |
| |
| private StripedReader stripedReader; |
| private final DataNode datanode; |
| private final Configuration conf; |
| |
| private final short index; // internal block index |
| private final ExtendedBlock block; |
| private final DatanodeInfo source; |
| private BlockReader blockReader; |
| private ByteBuffer buffer; |
| private boolean isLocal; |
| |
| StripedBlockReader(StripedReader stripedReader, DataNode datanode, |
| Configuration conf, short index, ExtendedBlock block, |
| DatanodeInfo source, long offsetInBlock) { |
| this.stripedReader = stripedReader; |
| this.datanode = datanode; |
| this.conf = conf; |
| |
| this.index = index; |
| this.source = source; |
| this.block = block; |
| this.isLocal = false; |
| |
| BlockReader tmpBlockReader = createBlockReader(offsetInBlock); |
| if (tmpBlockReader != null) { |
| this.blockReader = tmpBlockReader; |
| } |
| } |
| |
| ByteBuffer getReadBuffer() { |
| if (buffer == null) { |
| this.buffer = stripedReader.allocateReadBuffer(); |
| } |
| return buffer; |
| } |
| |
| void freeReadBuffer() { |
| DataNodeFaultInjector.get().interceptFreeBlockReaderBuffer(); |
| buffer = null; |
| } |
| |
| void resetBlockReader(long offsetInBlock) { |
| this.blockReader = createBlockReader(offsetInBlock); |
| } |
| |
| private BlockReader createBlockReader(long offsetInBlock) { |
| if (offsetInBlock >= block.getNumBytes()) { |
| return null; |
| } |
| Peer peer = null; |
| try { |
| InetSocketAddress dnAddr = |
| stripedReader.getSocketAddress4Transfer(source); |
| Token<BlockTokenIdentifier> blockToken = datanode.getBlockAccessToken( |
| block, EnumSet.of(BlockTokenIdentifier.AccessMode.READ), |
| StorageType.EMPTY_ARRAY, new String[0]); |
| /* |
| * This can be further improved if the replica is local, then we can |
| * read directly from DN and need to check the replica is FINALIZED |
| * state, notice we should not use short-circuit local read which |
| * requires config for domain-socket in UNIX or legacy config in |
| * Windows. The network distance value isn't used for this scenario. |
| * |
| * TODO: add proper tracer |
| */ |
| peer = newConnectedPeer(block, dnAddr, blockToken, source); |
| if (peer.isLocal()) { |
| this.isLocal = true; |
| } |
| return BlockReaderRemote.newBlockReader( |
| "dummy", block, blockToken, offsetInBlock, |
| block.getNumBytes() - offsetInBlock, true, "", peer, source, |
| null, stripedReader.getCachingStrategy(), -1, conf); |
| } catch (IOException e) { |
| LOG.info("Exception while creating remote block reader, datanode {}", |
| source, e); |
| IOUtils.closeStream(peer); |
| return null; |
| } |
| } |
| |
| private Peer newConnectedPeer(ExtendedBlock b, InetSocketAddress addr, |
| Token<BlockTokenIdentifier> blockToken, |
| DatanodeID datanodeId) |
| throws IOException { |
| Peer peer = null; |
| boolean success = false; |
| Socket sock = null; |
| final int socketTimeout = datanode.getDnConf().getSocketTimeout(); |
| try { |
| sock = NetUtils.getDefaultSocketFactory(conf).createSocket(); |
| NetUtils.connect(sock, addr, socketTimeout); |
| peer = DFSUtilClient.peerFromSocketAndKey(datanode.getSaslClient(), |
| sock, datanode.getDataEncryptionKeyFactoryForBlock(b), |
| blockToken, datanodeId, socketTimeout); |
| success = true; |
| return peer; |
| } finally { |
| if (!success) { |
| IOUtils.cleanupWithLogger(null, peer); |
| IOUtils.closeSocket(sock); |
| } |
| } |
| } |
| |
| Callable<BlockReadStats> readFromBlock(final int length, |
| final CorruptedBlocks corruptedBlocks) { |
| return new Callable<BlockReadStats>() { |
| |
| @Override |
| public BlockReadStats call() throws Exception { |
| try { |
| getReadBuffer().limit(length); |
| return actualReadFromBlock(); |
| } catch (ChecksumException e) { |
| LOG.warn("Found Checksum error for {} from {} at {}", block, |
| source, e.getPos()); |
| corruptedBlocks.addCorruptedBlock(block, source); |
| throw e; |
| } catch (IOException e) { |
| LOG.info(e.getMessage()); |
| throw e; |
| } finally { |
| DataNodeFaultInjector.get().interceptBlockReader(); |
| } |
| } |
| }; |
| } |
| |
| /** |
| * Perform actual reading of bytes from block. |
| */ |
| private BlockReadStats actualReadFromBlock() throws IOException { |
| DataNodeFaultInjector.get().delayBlockReader(); |
| int len = buffer.remaining(); |
| int n = 0; |
| while (n < len) { |
| int nread = blockReader.read(buffer); |
| if (nread <= 0) { |
| break; |
| } |
| n += nread; |
| stripedReader.getReconstructor().incrBytesRead(isLocal, nread); |
| } |
| return new BlockReadStats(n, blockReader.isShortCircuit(), |
| blockReader.getNetworkDistance()); |
| } |
| |
| // close block reader |
| void closeBlockReader() { |
| IOUtils.closeStream(blockReader); |
| blockReader = null; |
| } |
| |
| short getIndex() { |
| return index; |
| } |
| |
| BlockReader getBlockReader() { |
| return blockReader; |
| } |
| } |