Example usage for org.apache.hadoop.fs BlockLocation getStorageIds

Introduction

In this page you can find the example usage for org.apache.hadoop.fs BlockLocation getStorageIds.

Prototype

public String[] getStorageIds() 

Source Link

Document

Get the storageID of each replica of the block.

Usage

From source file:org.apache.impala.catalog.HdfsTable.java

License:Apache License

/**
 * Loads the disk IDs for BlockLocation 'location' and its corresponding file block.
 * HDFS API for BlockLocation returns a storageID UUID string for each disk
 * hosting the block, which is then mapped to a 0-based integer id called disk ID.
 * Returns the number of unknown disk IDs encountered in this process.
 *///from w  w  w  .  j a v  a 2s. co  m
private int loadDiskIds(BlockLocation location, THdfsFileBlock fileBlock) {
    int unknownDiskIdCount = 0;
    String[] storageIds = location.getStorageIds();
    String[] hosts;
    try {
        hosts = location.getHosts();
    } catch (IOException e) {
        LOG.error("Couldn't get hosts for block: " + location.toString(), e);
        return unknownDiskIdCount;
    }
    if (storageIds.length != hosts.length) {
        LOG.error("Number of storage IDs and number of hosts for block: " + location.toString()
                + " mismatch. Skipping disk ID loading for this block.");
        return unknownDiskIdCount;
    }
    int[] diskIDs = new int[storageIds.length];
    for (int i = 0; i < storageIds.length; ++i) {
        if (Strings.isNullOrEmpty(storageIds[i])) {
            diskIDs[i] = -1;
            ++unknownDiskIdCount;
        } else {
            diskIDs[i] = DiskIdMapper.INSTANCE.getDiskId(hosts[i], storageIds[i]);
        }
    }
    FileBlock.setDiskIds(diskIDs, fileBlock);
    return unknownDiskIdCount;
}

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