Examples with Scanner org.apache.accumulo.core.client.Scanner used on opensource projects

Example 16 with Scanner

use of org.apache.accumulo.core.client.Scanner in project presto by prestodb.

the class AccumuloClient method getDefaultTabletLocation.

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();
    }
}

Example 17 with Scanner

use of org.apache.accumulo.core.client.Scanner in project gora by apache.

the class AccumuloStore method createScanner.

private Scanner createScanner(Query<K, T> query) throws TableNotFoundException {
    // TODO make isolated scanner optional?
    Scanner scanner = new IsolatedScanner(conn.createScanner(mapping.tableName, Authorizations.EMPTY));
    setFetchColumns(scanner, query.getFields());
    scanner.setRange(createRange(query));
    if (query.getStartTime() != -1 || query.getEndTime() != -1) {
        IteratorSetting is = new IteratorSetting(30, TimestampFilter.class);
        if (query.getStartTime() != -1)
            TimestampFilter.setStart(is, query.getStartTime(), true);
        if (query.getEndTime() != -1)
            TimestampFilter.setEnd(is, query.getEndTime(), true);
        scanner.addScanIterator(is);
    }
    return scanner;
}

Example 18 with Scanner

use of org.apache.accumulo.core.client.Scanner in project gora by apache.

the class AccumuloStore method deleteByQuery.

@Override
public long deleteByQuery(Query<K, T> query) {
    try {
        Scanner scanner = createScanner(query);
        // add iterator that drops values on the server side
        scanner.addScanIterator(new IteratorSetting(Integer.MAX_VALUE, SortedKeyIterator.class));
        RowIterator iterator = new RowIterator(scanner.iterator());
        long count = 0;
        while (iterator.hasNext()) {
            Iterator<Entry<Key, Value>> row = iterator.next();
            Mutation m = null;
            while (row.hasNext()) {
                Entry<Key, Value> entry = row.next();
                Key key = entry.getKey();
                if (m == null)
                    m = new Mutation(key.getRow());
                // TODO optimize to avoid continually creating column vis? prob does not matter for empty
                m.putDelete(key.getColumnFamily(), key.getColumnQualifier(), new ColumnVisibility(key.getColumnVisibility()), key.getTimestamp());
            }
            getBatchWriter().addMutation(m);
            count++;
        }
        return count;
    } catch (TableNotFoundException e) {
        // TODO return 0?
        LOG.error(e.getMessage(), e);
        return 0;
    } catch (MutationsRejectedException e) {
        LOG.error(e.getMessage(), e);
        return 0;
    } catch (IOException e) {
        LOG.error(e.getMessage(), e);
        return 0;
    }
}

Example 19 with Scanner

use of org.apache.accumulo.core.client.Scanner in project gora by apache.

the class AccumuloStore method get.

@Override
public T get(K key, String[] fields) {
    try {
        // TODO make isolated scanner optional?
        Scanner scanner = new IsolatedScanner(conn.createScanner(mapping.tableName, Authorizations.EMPTY));
        Range rowRange = new Range(new Text(toBytes(key)));
        scanner.setRange(rowRange);
        setFetchColumns(scanner, fields);
        T persistent = newPersistent();
        ByteSequence row = populate(scanner.iterator(), persistent);
        if (row == null)
            return null;
        return persistent;
    } catch (TableNotFoundException e) {
        LOG.error(e.getMessage(), e);
        return null;
    } catch (IOException e) {
        LOG.error(e.getMessage(), e);
        return null;
    }
}