How to use

setRange

method

in

org.apache.accumulo.core.client.Scanner

/**
 * Gets a scanner from Accumulo over one row.
 *
 * @param row the row to scan
 * @param fields the set of columns to scan
 * @return an Accumulo {@link Scanner} bound to the given row and columns
 */
private Scanner getRow(String table, Text row, Set<String> fields) throws TableNotFoundException {
 Scanner scanner = connector.createScanner(table, Authorizations.EMPTY);
 scanner.setRange(new Range(row));
 if (fields != null) {
  for (String field : fields) {
   scanner.fetchColumn(colFam, new Text(field));
  }
 }
 return scanner;
}

protected int removeReplicationEntries(Map<UUID,TServerInstance> candidates) {
 try {
  try {
   final Scanner s = ReplicationTable.getScanner(context);
   StatusSection.limit(s);
   for (Entry<Key,Value> entry : s) {
    UUID id = path2uuid(new Path(entry.getKey().getRow().toString()));
    candidates.remove(id);
    log.info("Ignore closed log " + id + " because it is being replicated");
   }
  } catch (ReplicationTableOfflineException ex) {
   return candidates.size();
  }
  final Scanner scanner = context.createScanner(MetadataTable.NAME, Authorizations.EMPTY);
  scanner.fetchColumnFamily(MetadataSchema.ReplicationSection.COLF);
  scanner.setRange(MetadataSchema.ReplicationSection.getRange());
  for (Entry<Key,Value> entry : scanner) {
   Text file = new Text();
   MetadataSchema.ReplicationSection.getFile(entry.getKey(), file);
   UUID id = path2uuid(new Path(file.toString()));
   candidates.remove(id);
   log.info("Ignore closed log " + id + " because it is being replicated");
  }
  return candidates.size();
 } catch (TableNotFoundException e) {
  log.error("Failed to scan metadata table", e);
  throw new IllegalArgumentException(e);
 }
}

/**
 * Gets a scanner from Accumulo over one row.
 *
 * @param row the row to scan
 * @param fields the set of columns to scan
 * @return an Accumulo {@link Scanner} bound to the given row and columns
 */
private Scanner getRow(String table, Text row, Set<String> fields) throws TableNotFoundException {
 Scanner scanner = connector.createScanner(table, Authorizations.EMPTY);
 scanner.setRange(new Range(row));
 if (fields != null) {
  for (String field : fields) {
   scanner.fetchColumn(colFam, new Text(field));
  }
 }
 return scanner;
}

/**
 * During an upgrade we need to move deletion requests for files under the !METADATA table to the
 * root tablet.
 */
public static void moveMetaDeleteMarkers(ServerContext context) {
 String oldDeletesPrefix = "!!~del";
 Range oldDeletesRange = new Range(oldDeletesPrefix, true, "!!~dem", false);
 // move old delete markers to new location, to standardize table schema between all metadata
 // tables
 try (Scanner scanner = new ScannerImpl(context, RootTable.ID, Authorizations.EMPTY)) {
  scanner.setRange(oldDeletesRange);
  for (Entry<Key,Value> entry : scanner) {
   String row = entry.getKey().getRow().toString();
   if (row.startsWith(oldDeletesPrefix)) {
    moveDeleteEntry(context, RootTable.OLD_EXTENT, entry, row, oldDeletesPrefix);
   } else {
    break;
   }
  }
 }
}

/**
 * Gets a scanner from Accumulo over one row.
 *
 * @param row the row to scan
 * @param fields the set of columns to scan
 * @return an Accumulo {@link Scanner} bound to the given row and columns
 */
private Scanner getRow(String table, Text row, Set<String> fields) throws TableNotFoundException {
 Scanner scanner = connector.createScanner(table, Authorizations.EMPTY);
 scanner.setRange(new Range(row));
 if (fields != null) {
  for (String field : fields) {
   scanner.fetchColumn(colFam, new Text(field));
  }
 }
 return scanner;
}

public static Map<Long,? extends Collection<FileRef>> getBulkFilesLoaded(ServerContext context,
  KeyExtent extent) {
 Text metadataRow = extent.getMetadataEntry();
 Map<Long,List<FileRef>> result = new HashMap<>();
 VolumeManager fs = context.getVolumeManager();
 try (Scanner scanner = new ScannerImpl(context,
   extent.isMeta() ? RootTable.ID : MetadataTable.ID, Authorizations.EMPTY)) {
  scanner.setRange(new Range(metadataRow));
  scanner.fetchColumnFamily(TabletsSection.BulkFileColumnFamily.NAME);
  for (Entry<Key,Value> entry : scanner) {
   Long tid = Long.parseLong(entry.getValue().toString());
   List<FileRef> lst = result.get(tid);
   if (lst == null) {
    result.put(tid, lst = new ArrayList<>());
   }
   lst.add(new FileRef(fs, entry.getKey()));
  }
 }
 return result;
}

public static Pair<byte[], byte[]> getMinMaxRowIds(Connector connector, AccumuloTable table, Authorizations auths)
    throws TableNotFoundException
{
  Scanner scanner = connector.createScanner(table.getMetricsTableName(), auths);
  scanner.setRange(new Range(new Text(Indexer.METRICS_TABLE_ROW_ID.array())));
  Text family = new Text(Indexer.METRICS_TABLE_ROWS_CF.array());
  Text firstRowQualifier = new Text(Indexer.METRICS_TABLE_FIRST_ROW_CQ.array());
  Text lastRowQualifier = new Text(Indexer.METRICS_TABLE_LAST_ROW_CQ.array());
  scanner.fetchColumn(family, firstRowQualifier);
  scanner.fetchColumn(family, lastRowQualifier);
  byte[] firstRow = null;
  byte[] lastRow = null;
  for (Entry<Key, Value> entry : scanner) {
    if (entry.getKey().compareColumnQualifier(firstRowQualifier) == 0) {
      firstRow = entry.getValue().get();
    }
    if (entry.getKey().compareColumnQualifier(lastRowQualifier) == 0) {
      lastRow = entry.getValue().get();
    }
  }
  scanner.close();
  return Pair.of(firstRow, lastRow);
}

public static List<FileRef> getBulkFilesLoaded(ServerContext context, AccumuloClient client,
  KeyExtent extent, long tid) {
 List<FileRef> result = new ArrayList<>();
 try (Scanner mscanner = new IsolatedScanner(client.createScanner(
   extent.isMeta() ? RootTable.NAME : MetadataTable.NAME, Authorizations.EMPTY))) {
  VolumeManager fs = context.getVolumeManager();
  mscanner.setRange(extent.toMetadataRange());
  mscanner.fetchColumnFamily(TabletsSection.BulkFileColumnFamily.NAME);
  for (Entry<Key,Value> entry : mscanner) {
   if (Long.parseLong(entry.getValue().toString()) == tid) {
    result.add(new FileRef(fs, entry.getKey()));
   }
  }
  return result;
 } catch (TableNotFoundException ex) {
  // unlikely
  throw new RuntimeException("Onos! teh metadata table has vanished!!");
 }
}

private long getNumRowsInTable(String metricsTable, Authorizations auths)
    throws TableNotFoundException
{
  // Create scanner against the metrics table, pulling the special column and the rows column
  Scanner scanner = connector.createScanner(metricsTable, auths);
  scanner.setRange(METRICS_TABLE_ROWID_RANGE);
  scanner.fetchColumn(METRICS_TABLE_ROWS_CF_AS_TEXT, CARDINALITY_CQ_AS_TEXT);
  // Scan the entry and get the number of rows
  long numRows = -1;
  for (Entry<Key, Value> entry : scanner) {
    if (numRows > 0) {
      throw new PrestoException(FUNCTION_IMPLEMENTATION_ERROR, "Should have received only one entry when scanning for number of rows in metrics table");
    }
    numRows = Long.parseLong(entry.getValue().toString());
  }
  scanner.close();
  LOG.debug("Number of rows in table is %d", numRows);
  return numRows;
}

metadata.setRange(range);
metadata.fetchColumnFamily(DataFileColumnFamily.NAME);
int count = 0;
 Key key = entry.getKey();
 Path map = fs.getFullPath(key);

private Optional<String> getDefaultTabletLocation(String fulltable)
{
  try {
    String tableId = connector.tableOperations().tableIdMap().get(fulltable);
    // Create a scanner over the metadata table, fetching the 'loc' column of the default tablet row
    Scanner scan = connector.createScanner("accumulo.metadata", connector.securityOperations().getUserAuthorizations(username));
    scan.fetchColumnFamily(new Text("loc"));
    scan.setRange(new Range(tableId + '<'));
    // scan the entry
    Optional<String> location = Optional.empty();
    for (Entry<Key, Value> entry : scan) {
      if (location.isPresent()) {
        throw new PrestoException(FUNCTION_IMPLEMENTATION_ERROR, "Scan for default tablet returned more than one entry");
      }
      location = Optional.of(entry.getValue().toString());
    }
    scan.close();
    return location;
  }
  catch (Exception e) {
    // Swallow this exception so the query does not fail due to being unable to locate the tablet server for the default tablet.
    // This is purely an optimization, but we will want to log the error.
    LOG.error("Failed to get tablet location, returning dummy location", e);
    return Optional.empty();
  }
}

TabletsSection.TabletColumnFamily.PREV_ROW_COLUMN.fetch(metaScanner);
TabletsSection.ServerColumnFamily.TIME_COLUMN.fetch(metaScanner);
metaScanner.setRange(new KeyExtent(tableID, null, null).toMetadataRange());
 entry.getKey().write(dataOut);
 entry.getValue().write(dataOut);
 if (entry.getKey().getColumnFamily().equals(DataFileColumnFamily.NAME)) {
  String path = fs.getFullPath(entry.getKey()).toString();
  String tokens[] = path.split("/");
  if (tokens.length < 1) {

scanner = connector.createScanner(table, Authorizations.EMPTY);
scanner.setRange(new Range(new Text(startkey), null));
for (Entry<Key, Value> entry : scanner) {
 SortedMap<Key, Value> row = WholeRowIterator.decodeRow(entry.getKey(), entry.getValue());
 HashMap<String, ByteIterator> rowData;
 if (null != fields) {
  rowEntry.getKey().getColumnQualifier(cq);
  rowData.put(cq.toString(), new ByteArrayByteIterator(rowEntry.getValue().get()));

scanner.fetchColumnFamily(TabletsSection.CurrentLocationColumnFamily.NAME);
scanner.fetchColumnFamily(DataFileColumnFamily.NAME);
scanner.setRange(MetadataSchema.TabletsSection.getRange());
 Key key = entry.getKey();
 if (key.compareColumnFamily(TabletsSection.CurrentLocationColumnFamily.NAME) == 0) {
  String location = entry.getValue().toString();
 final String host = entry.getKey();
 final Long blocksForHost = entry.getValue();
 System.out.println(String.format("%15s %5.1f %8d", host,

scanner = connector.createScanner(table, Authorizations.EMPTY);
scanner.setRange(new Range(new Text(startkey), null));
for (Entry<Key, Value> entry : scanner) {
 SortedMap<Key, Value> row = WholeRowIterator.decodeRow(entry.getKey(), entry.getValue());
 HashMap<String, ByteIterator> rowData;
 if (null != fields) {
  rowEntry.getKey().getColumnQualifier(cq);
  rowData.put(cq.toString(), new ByteArrayByteIterator(rowEntry.getValue().get()));

mdScanner.setRange(new KeyExtent(tableId, null, null).toMetadataRange());
 String file = entry.getKey().getColumnQualifier().toString();
 String parts[] = file.split("/");
TreeSet<String> tableNames = new TreeSet<>();
for (Table.ID tableId : entry.getKey())
 tableNames.add(reverseTableIdMap.get(tableId));

scanner = connector.createScanner(table, Authorizations.EMPTY);
scanner.setRange(new Range(new Text(startkey), null));
for (Entry<Key, Value> entry : scanner) {
 SortedMap<Key, Value> row = WholeRowIterator.decodeRow(entry.getKey(), entry.getValue());
 HashMap<String, ByteIterator> rowData;
 if (null != fields) {
  rowEntry.getKey().getColumnQualifier(cq);
  rowData.put(cq.toString(), new ByteArrayByteIterator(rowEntry.getValue().get()));

scanner.setRange(MetadataSchema.TabletsSection.getRange());
scanner.fetchColumnFamily(MetadataSchema.TabletsSection.DataFileColumnFamily.NAME);
scanner.fetchColumnFamily(MetadataSchema.TabletsSection.LogColumnFamily.NAME);
 if (entry.getKey().getColumnFamily()
   .equals(MetadataSchema.TabletsSection.DataFileColumnFamily.NAME)) {
  volumes.add(getTableURI(entry.getKey().getColumnQualifier().toString()));
 } else if (entry.getKey().getColumnFamily()
   .equals(MetadataSchema.TabletsSection.LogColumnFamily.NAME)) {
  LogEntry le = LogEntry.fromKeyValue(entry.getKey(), entry.getValue());
scanner.setRange(MetadataSchema.DeletesSection.getRange());

Scanner scanner = connector.createScanner("accumulo.metadata", auths);
scanner.fetchColumnFamily(new Text("loc"));
Key start = new Key(tableId);
Key end = defaultTabletRow.followingKey(PartialKey.ROW);
scanner.setRange(new Range(start, end));
    byte[] keyBytes = entry.getKey().getRow().copyBytes();

public static SortedMap<FileRef,DataFileValue> getDataFileSizes(KeyExtent extent,
  ServerContext context) {
 TreeMap<FileRef,DataFileValue> sizes = new TreeMap<>();
 try (Scanner mdScanner = new ScannerImpl(context, MetadataTable.ID, Authorizations.EMPTY)) {
  mdScanner.fetchColumnFamily(DataFileColumnFamily.NAME);
  Text row = extent.getMetadataEntry();
  Key endKey = new Key(row, DataFileColumnFamily.NAME, new Text(""));
  endKey = endKey.followingKey(PartialKey.ROW_COLFAM);
  mdScanner.setRange(new Range(new Key(row), endKey));
  for (Entry<Key,Value> entry : mdScanner) {
   if (!entry.getKey().getRow().equals(row))
    break;
   DataFileValue dfv = new DataFileValue(entry.getValue().get());
   sizes.put(new FileRef(context.getVolumeManager(), entry.getKey()), dfv);
  }
  return sizes;
 }
}