Examples with FileIoProvider org.apache.hadoop.hdfs.server.datanode.FileIoProvider used on opensource projects

Example 1 with FileIoProvider

use of org.apache.hadoop.hdfs.server.datanode.FileIoProvider in project hadoop by apache.

the class FsDatasetImpl method checkAndUpdate.

/**
   * Reconcile the difference between blocks on the disk and blocks in
   * volumeMap
   *
   * Check the given block for inconsistencies. Look at the
   * current state of the block and reconcile the differences as follows:
   * <ul>
   * <li>If the block file is missing, delete the block from volumeMap</li>
   * <li>If the block file exists and the block is missing in volumeMap,
   * add the block to volumeMap <li>
   * <li>If generation stamp does not match, then update the block with right
   * generation stamp</li>
   * <li>If the block length in memory does not match the actual block file length
   * then mark the block as corrupt and update the block length in memory</li>
   * <li>If the file in {@link ReplicaInfo} does not match the file on
   * the disk, update {@link ReplicaInfo} with the correct file</li>
   * </ul>
   *
   * @param blockId Block that differs
   * @param diskFile Block file on the disk
   * @param diskMetaFile Metadata file from on the disk
   * @param vol Volume of the block file
   */
@Override
public void checkAndUpdate(String bpid, long blockId, File diskFile, File diskMetaFile, FsVolumeSpi vol) throws IOException {
    Block corruptBlock = null;
    ReplicaInfo memBlockInfo;
    try (AutoCloseableLock lock = datasetLock.acquire()) {
        memBlockInfo = volumeMap.get(bpid, blockId);
        if (memBlockInfo != null && memBlockInfo.getState() != ReplicaState.FINALIZED) {
            // Block is not finalized - ignore the difference
            return;
        }
        final FileIoProvider fileIoProvider = datanode.getFileIoProvider();
        final boolean diskMetaFileExists = diskMetaFile != null && fileIoProvider.exists(vol, diskMetaFile);
        final boolean diskFileExists = diskFile != null && fileIoProvider.exists(vol, diskFile);
        final long diskGS = diskMetaFileExists ? Block.getGenerationStamp(diskMetaFile.getName()) : HdfsConstants.GRANDFATHER_GENERATION_STAMP;
        if (!diskFileExists) {
            if (memBlockInfo == null) {
                // If metadata file exists then delete it
                if (diskMetaFileExists && fileIoProvider.delete(vol, diskMetaFile)) {
                    LOG.warn("Deleted a metadata file without a block " + diskMetaFile.getAbsolutePath());
                }
                return;
            }
            if (!memBlockInfo.blockDataExists()) {
                // Block is in memory and not on the disk
                // Remove the block from volumeMap
                volumeMap.remove(bpid, blockId);
                if (vol.isTransientStorage()) {
                    ramDiskReplicaTracker.discardReplica(bpid, blockId, true);
                }
                LOG.warn("Removed block " + blockId + " from memory with missing block file on the disk");
                // Finally remove the metadata file
                if (diskMetaFileExists && fileIoProvider.delete(vol, diskMetaFile)) {
                    LOG.warn("Deleted a metadata file for the deleted block " + diskMetaFile.getAbsolutePath());
                }
            }
            return;
        }
        /*
       * Block file exists on the disk
       */
        if (memBlockInfo == null) {
            // Block is missing in memory - add the block to volumeMap
            ReplicaInfo diskBlockInfo = new ReplicaBuilder(ReplicaState.FINALIZED).setBlockId(blockId).setLength(diskFile.length()).setGenerationStamp(diskGS).setFsVolume(vol).setDirectoryToUse(diskFile.getParentFile()).build();
            volumeMap.add(bpid, diskBlockInfo);
            if (vol.isTransientStorage()) {
                long lockedBytesReserved = cacheManager.reserve(diskBlockInfo.getNumBytes()) > 0 ? diskBlockInfo.getNumBytes() : 0;
                ramDiskReplicaTracker.addReplica(bpid, blockId, (FsVolumeImpl) vol, lockedBytesReserved);
            }
            LOG.warn("Added missing block to memory " + diskBlockInfo);
            return;
        }
        // Compare block files
        if (memBlockInfo.blockDataExists()) {
            if (memBlockInfo.getBlockURI().compareTo(diskFile.toURI()) != 0) {
                if (diskMetaFileExists) {
                    if (memBlockInfo.metadataExists()) {
                        // We have two sets of block+meta files. Decide which one to
                        // keep.
                        ReplicaInfo diskBlockInfo = new ReplicaBuilder(ReplicaState.FINALIZED).setBlockId(blockId).setLength(diskFile.length()).setGenerationStamp(diskGS).setFsVolume(vol).setDirectoryToUse(diskFile.getParentFile()).build();
                        ((FsVolumeImpl) vol).resolveDuplicateReplicas(bpid, memBlockInfo, diskBlockInfo, volumeMap);
                    }
                } else {
                    if (!fileIoProvider.delete(vol, diskFile)) {
                        LOG.warn("Failed to delete " + diskFile);
                    }
                }
            }
        } else {
            // Block refers to a block file that does not exist.
            // Update the block with the file found on the disk. Since the block
            // file and metadata file are found as a pair on the disk, update
            // the block based on the metadata file found on the disk
            LOG.warn("Block file in replica " + memBlockInfo.getBlockURI() + " does not exist. Updating it to the file found during scan " + diskFile.getAbsolutePath());
            memBlockInfo.updateWithReplica(StorageLocation.parse(diskFile.toString()));
            LOG.warn("Updating generation stamp for block " + blockId + " from " + memBlockInfo.getGenerationStamp() + " to " + diskGS);
            memBlockInfo.setGenerationStamp(diskGS);
        }
        // Compare generation stamp
        if (memBlockInfo.getGenerationStamp() != diskGS) {
            File memMetaFile = FsDatasetUtil.getMetaFile(diskFile, memBlockInfo.getGenerationStamp());
            if (fileIoProvider.exists(vol, memMetaFile)) {
                String warningPrefix = "Metadata file in memory " + memMetaFile.getAbsolutePath() + " does not match file found by scan ";
                if (!diskMetaFileExists) {
                    LOG.warn(warningPrefix + "null");
                } else if (memMetaFile.compareTo(diskMetaFile) != 0) {
                    LOG.warn(warningPrefix + diskMetaFile.getAbsolutePath());
                }
            } else {
                // as the block file, then use the generation stamp from it
                try {
                    File memFile = new File(memBlockInfo.getBlockURI());
                    long gs = diskMetaFileExists && diskMetaFile.getParent().equals(memFile.getParent()) ? diskGS : HdfsConstants.GRANDFATHER_GENERATION_STAMP;
                    LOG.warn("Updating generation stamp for block " + blockId + " from " + memBlockInfo.getGenerationStamp() + " to " + gs);
                    memBlockInfo.setGenerationStamp(gs);
                } catch (IllegalArgumentException e) {
                    //exception arises because the URI cannot be converted to a file
                    LOG.warn("Block URI could not be resolved to a file", e);
                }
            }
        }
        // Compare block size
        if (memBlockInfo.getNumBytes() != memBlockInfo.getBlockDataLength()) {
            // Update the length based on the block file
            corruptBlock = new Block(memBlockInfo);
            LOG.warn("Updating size of block " + blockId + " from " + memBlockInfo.getNumBytes() + " to " + memBlockInfo.getBlockDataLength());
            memBlockInfo.setNumBytes(memBlockInfo.getBlockDataLength());
        }
    }
    // Send corrupt block report outside the lock
    if (corruptBlock != null) {
        LOG.warn("Reporting the block " + corruptBlock + " as corrupt due to length mismatch");
        try {
            datanode.reportBadBlocks(new ExtendedBlock(bpid, corruptBlock), memBlockInfo.getVolume());
        } catch (IOException e) {
            LOG.warn("Failed to repot bad block " + corruptBlock, e);
        }
    }
}