Field Detail

• LOG

  public static final org.apache.commons.logging.Log LOG

• SNAPSHOT_NAME_KEY

  private static final String SNAPSHOT_NAME_KEY

  See Also:

  Constant Field Values

• RESTORE_DIR_KEY

  protected static final String RESTORE_DIR_KEY

  See Also:

  Constant Field Values

• LOCALITY_CUTOFF_MULTIPLIER

  private static final String LOCALITY_CUTOFF_MULTIPLIER

  See getBestLocations(Configuration, HDFSBlocksDistribution)

  See Also:

  Constant Field Values

• DEFAULT_LOCALITY_CUTOFF_MULTIPLIER

  private static final float DEFAULT_LOCALITY_CUTOFF_MULTIPLIER

  See Also:

  Constant Field Values

Constructor Detail

• TableSnapshotInputFormatImpl

  public TableSnapshotInputFormatImpl()

Method Detail

• getSplits

  public static List<TableSnapshotInputFormatImpl.InputSplit> getSplits(org.apache.hadoop.conf.Configuration conf)
                                                                 throws IOException

  Throws:

  IOException

• getRegionInfosFromManifest

  public static List<HRegionInfo> getRegionInfosFromManifest(SnapshotManifest manifest)

• getSnapshotManifest

  public static SnapshotManifest getSnapshotManifest(org.apache.hadoop.conf.Configuration conf,
                                     String snapshotName,
                                     org.apache.hadoop.fs.Path rootDir,
                                     org.apache.hadoop.fs.FileSystem fs)
                                              throws IOException

  Throws:

  IOException

• extractScanFromConf

  public static Scan extractScanFromConf(org.apache.hadoop.conf.Configuration conf)
                                  throws IOException

  Throws:

  IOException

• getSplits

  public static List<TableSnapshotInputFormatImpl.InputSplit> getSplits(Scan scan,
                                                        SnapshotManifest manifest,
                                                        List<HRegionInfo> regionManifests,
                                                        org.apache.hadoop.fs.Path restoreDir,
                                                        org.apache.hadoop.conf.Configuration conf)
                                                                 throws IOException

  Throws:

  IOException

• getBestLocations

  public static List<String> getBestLocations(org.apache.hadoop.conf.Configuration conf,
                              HDFSBlocksDistribution blockDistribution)

  This computes the locations to be passed from the InputSplit. MR/Yarn schedulers does not take weights into account, thus will treat every location passed from the input split as equal. We do not want to blindly pass all the locations, since we are creating one split per region, and the region's blocks are all distributed throughout the cluster unless favorite node assignment is used. On the expected stable case, only one location will contain most of the blocks as local. On the other hand, in favored node assignment, 3 nodes will contain highly local blocks. Here we are doing a simple heuristic, where we will pass all hosts which have at least 80% (hbase.tablesnapshotinputformat.locality.cutoff.multiplier) as much block locality as the top host with the best locality.

• getSnapshotName

  private static String getSnapshotName(org.apache.hadoop.conf.Configuration conf)

• setInput

  public static void setInput(org.apache.hadoop.conf.Configuration conf,
              String snapshotName,
              org.apache.hadoop.fs.Path restoreDir)
                       throws IOException

  Configures the job to use TableSnapshotInputFormat to read from a snapshot.

  Parameters:

  conf - the job to configure

  snapshotName - the name of the snapshot to read from

  restoreDir - a temporary directory to restore the snapshot into. Current user should have write permissions to this directory, and this should not be a subdirectory of rootdir. After the job is finished, restoreDir can be deleted.

  Throws:

  IOException - if an error occurs