Example usage for org.apache.hadoop.hdfs.server.datanode ReplicaHandler getReplica

Introduction

In this page you can find the example usage for org.apache.hadoop.hdfs.server.datanode ReplicaHandler getReplica.

Prototype

public ReplicaInPipeline getReplica() 

Source Link

Usage

From source file:backup.datanode.DataNodeRestoreProcessor.java

License:Apache License

public void restoreBlock(ExtendedBlock extendedBlock) throws Exception {
    if (!_backupStore.hasBlock(extendedBlock)) {
        LOG.error("Can not restore block, not in block store {}", extendedBlock);
        return;//  w  ww.  j  a  v a 2s .  c  o m
    }
    FsDatasetSpi<?> fsDataset = _datanode.getFSDataset();
    org.apache.hadoop.hdfs.protocol.ExtendedBlock heb = BackupUtil.toHadoop(extendedBlock);
    if (fsDataset.isValidBlock(heb)) {
        LOG.info("Block already restored {}", extendedBlock);
        return;
    }
    try {
        _restoreInProgress.incrementAndGet();
        LOG.info("Restoring block {}", extendedBlock);
        boolean allowLazyPersist = true;
        // org.apache.hadoop.fs.StorageType storageType =
        // org.apache.hadoop.fs.StorageType.DEFAULT;
        org.apache.hadoop.hdfs.StorageType storageType = org.apache.hadoop.hdfs.StorageType.DEFAULT;
        ReplicaHandler replicaHandler = fsDataset.createRbw(storageType, heb, allowLazyPersist);
        ReplicaInPipelineInterface pipelineInterface = replicaHandler.getReplica();
        boolean isCreate = true;
        DataChecksum requestedChecksum = DataChecksum.newDataChecksum(_checksumType, _bytesPerChecksum);
        int bytesCopied = 0;
        try (ReplicaOutputStreams streams = pipelineInterface.createStreams(isCreate, requestedChecksum)) {
            try (OutputStream checksumOut = streams.getChecksumOut()) {
                try (InputStream metaData = _backupStore.getMetaDataInputStream(extendedBlock)) {
                    LOG.info("Restoring meta data for block {}", extendedBlock);
                    IOUtils.copy(trackThroughPut(metaData), checksumOut);
                }
            }
            try (OutputStream dataOut = streams.getDataOut()) {
                try (InputStream data = _backupStore.getDataInputStream(extendedBlock)) {
                    LOG.info("Restoring data for block {}", extendedBlock);
                    bytesCopied = IOUtils.copy(trackThroughPut(data), dataOut);
                }
            }
        }
        pipelineInterface.setNumBytes(bytesCopied);
        LOG.info("Finalizing restored block {}", extendedBlock);
        fsDataset.finalizeBlock(heb);

        // datanode.notifyNamenodeReceivedBlock(extendedBlock, "",
        // pipelineInterface.getStorageUuid();
        _datanode.notifyNamenodeReceivedBlock(heb, "", pipelineInterface.getStorageUuid(),
                pipelineInterface.isOnTransientStorage());
    } catch (ReplicaAlreadyExistsException e) {
        LOG.info("Restoring block already exists {}", extendedBlock);
    } finally {
        _restoreInProgress.decrementAndGet();
    }
}

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