Examples with PCJStorageException org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.PCJStorageException used on opensource projects

Example 6 with PCJStorageException

use of org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.PCJStorageException in project incubator-rya by apache.

the class PcjTablesIT method dropPcj.

@Test
public void dropPcj() throws PCJStorageException, AccumuloException, AccumuloSecurityException {
    final Connector accumuloConn = cluster.getConnector();
    // Create a PCJ index.
    final String tableName = new PcjTableNameFactory().makeTableName(getRyaInstanceName(), "thePcj");
    final Set<VariableOrder> varOrders = Sets.<VariableOrder>newHashSet(new VariableOrder("x"));
    final String sparql = "SELECT x WHERE ?x <http://isA> <http://Food>";
    final PcjTables pcjs = new PcjTables();
    pcjs.createPcjTable(accumuloConn, tableName, varOrders, sparql);
    // Fetch its metadata to show that it has actually been created.
    final PcjMetadata expectedMetadata = new PcjMetadata(sparql, 0L, varOrders);
    PcjMetadata metadata = pcjs.getPcjMetadata(accumuloConn, tableName);
    assertEquals(expectedMetadata, metadata);
    // Drop it.
    pcjs.dropPcjTable(accumuloConn, tableName);
    // Show the metadata is no longer present.
    PCJStorageException tableDoesNotExistException = null;
    try {
        metadata = pcjs.getPcjMetadata(accumuloConn, tableName);
    } catch (final PCJStorageException e) {
        tableDoesNotExistException = e;
    }
    assertNotNull(tableDoesNotExistException);
}

Example 7 with PCJStorageException

use of org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.PCJStorageException in project incubator-rya by apache.

the class MongoPcjDocuments method populatePcj.

/**
 * Scan Rya for results that solve the PCJ's query and store them in the PCJ
 * document.
 * <p>
 * This method assumes the PCJ document has already been created.
 *
 * @param pcjId - The Id of the PCJ that will receive the results. (not null)
 * @param ryaConn - A connection to the Rya store that will be queried to find results. (not null)
 * @throws PCJStorageException If results could not be written to the PCJ results document,
 *  the PCJ results document does not exist, or the query that is being execute was malformed.
 */
public void populatePcj(final String pcjId, final RepositoryConnection ryaConn) throws PCJStorageException {
    checkNotNull(pcjId);
    checkNotNull(ryaConn);
    try {
        // Fetch the query that needs to be executed from the PCJ metadata document.
        final PcjMetadata pcjMetadata = getPcjMetadata(pcjId);
        final String sparql = pcjMetadata.getSparql();
        // Query Rya for results to the SPARQL query.
        final TupleQuery query = ryaConn.prepareTupleQuery(QueryLanguage.SPARQL, sparql);
        final TupleQueryResult results = query.evaluate();
        // Load batches of 1000 of them at a time into the PCJ results document.
        final Set<VisibilityBindingSet> batch = new HashSet<>(1000);
        while (results.hasNext()) {
            final VisibilityBindingSet bs = new VisibilityBindingSet(results.next());
            batch.add(bs);
            if (batch.size() == 1000) {
                addResults(pcjId, batch);
                batch.clear();
            }
        }
        if (!batch.isEmpty()) {
            addResults(pcjId, batch);
        }
    } catch (RepositoryException | MalformedQueryException | QueryEvaluationException e) {
        throw new PCJStorageException("Could not populate a PCJ document with Rya results for the pcj with Id: " + pcjId, e);
    }
}

Example 8 with PCJStorageException

use of org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.PCJStorageException in project incubator-rya by apache.

the class PcjTables method getPcjMetadata.

/**
 * Fetch the {@link PCJMetadata} from an Accumulo table.
 * <p>
 * This method assumes the PCJ table has already been created.
 *
 * @param accumuloConn - A connection to the Accumulo that hosts the PCJ table. (not null)
 * @param pcjTableName - The name of the table that will be search. (not null)
 * @return The PCJ Metadata that has been stolred in the in the PCJ Table.
 * @throws PCJStorageException The PCJ Table does not exist.
 */
public PcjMetadata getPcjMetadata(final Connector accumuloConn, final String pcjTableName) throws PCJStorageException {
    checkNotNull(accumuloConn);
    checkNotNull(pcjTableName);
    Scanner scanner = null;
    try {
        // Create an Accumulo scanner that iterates through the metadata entries.
        scanner = accumuloConn.createScanner(pcjTableName, new Authorizations());
        final Iterator<Entry<Key, Value>> entries = scanner.iterator();
        // No metadata has been stored in the table yet.
        if (!entries.hasNext()) {
            throw new PCJStorageException("Could not find any PCJ metadata in the table named: " + pcjTableName);
        }
        // Fetch the metadata from the entries. Assuming they all have the same cardinality and sparql query.
        String sparql = null;
        Long cardinality = null;
        final Set<VariableOrder> varOrders = new HashSet<>();
        while (entries.hasNext()) {
            final Entry<Key, Value> entry = entries.next();
            final Text columnQualifier = entry.getKey().getColumnQualifier();
            final byte[] value = entry.getValue().get();
            if (columnQualifier.equals(PCJ_METADATA_SPARQL_QUERY)) {
                sparql = stringLexicoder.decode(value);
            } else if (columnQualifier.equals(PCJ_METADATA_CARDINALITY)) {
                cardinality = longLexicoder.decode(value);
            } else if (columnQualifier.equals(PCJ_METADATA_VARIABLE_ORDERS)) {
                for (final String varOrderStr : listLexicoder.decode(value)) {
                    varOrders.add(new VariableOrder(varOrderStr));
                }
            }
        }
        return new PcjMetadata(sparql, cardinality, varOrders);
    } catch (final TableNotFoundException e) {
        throw new PCJStorageException("Could not add results to a PCJ because the PCJ table does not exist.", e);
    } finally {
        if (scanner != null) {
            scanner.close();
        }
    }
}

Example 9 with PCJStorageException

use of org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.PCJStorageException in project incubator-rya by apache.

the class PcjTables method createPcjTable.

/**
 * Create a new PCJ table within an Accumulo instance for a SPARQL query.
 * For example, calling the function like this:
 * <pre>
 * PcjTables.createPcjTable(
 *     accumuloConn,
 *
 *     "foo_INDEX_query1234",
 *
 *     Sets.newHashSet(
 *         new VariableOrder("city;worker;customer"),
 *         new VariableOrder("worker;customer;city") ,
 *         new VariableOrder("customer;city;worker")),
 *
 *     "SELECT ?customer ?worker ?city { " +
 *            "?customer &lt;http://talksTo> ?worker. " +
 *            "?worker &lt;http://livesIn> ?city. " +
 *            "?worker &lt;http://worksAt> &lt;http://Home>. " +
 *     "}");
 * </pre>
 * </p>
 * Will result in an Accumulo table named "foo_INDEX_query1234" with the following entries:
 * <table border="1" style="width:100%">
 *   <tr> <th>Row ID</td>  <th>Column</td>  <th>Value</td> </tr>
 *   <tr> <td>pcjMetadata</td> <td>metadata:sparql</td> <td> ... UTF-8 bytes encoding the query string ... </td> </tr>
 *   <tr> <td>pcjMetadata</td> <td>metadata:cardinality</td> <td> The query's cardinality </td> </tr>
 *   <tr> <td>pcjMetadata</td> <td>metadata:variableOrders</td> <td> The variable orders the results are written to </td> </tr>
 * </table>
 *
 * @param accumuloConn - A connection to the Accumulo that hosts the PCJ table. (not null)
 * @param pcjTableName - The name of the table that will be created. (not null)
 * @param varOrders - The variable orders the results within the table will be written to. (not null)
 * @param sparql - The query this table's results solves. (not null)
 * @throws PCJStorageException Could not create a new PCJ table either because Accumulo
 *   would not let us create it or the PCJ metadata was not able to be written to it.
 */
public void createPcjTable(final Connector accumuloConn, final String pcjTableName, final Set<VariableOrder> varOrders, final String sparql) throws PCJStorageException {
    checkNotNull(accumuloConn);
    checkNotNull(pcjTableName);
    checkNotNull(varOrders);
    checkNotNull(sparql);
    final TableOperations tableOps = accumuloConn.tableOperations();
    if (!tableOps.exists(pcjTableName)) {
        BatchWriter writer = null;
        try {
            // Create the new table in Accumulo.
            tableOps.create(pcjTableName);
            // Write the PCJ Metadata to the newly created table.
            final PcjMetadata pcjMetadata = new PcjMetadata(sparql, 0L, varOrders);
            final List<Mutation> mutations = makeWriteMetadataMutations(pcjMetadata);
            writer = accumuloConn.createBatchWriter(pcjTableName, new BatchWriterConfig());
            writer.addMutations(mutations);
        } catch (final TableExistsException e) {
            log.warn("Something else just created the Rya PCJ export table named '" + pcjTableName + "'. This is unexpected, but we will continue as normal.");
        } catch (AccumuloException | AccumuloSecurityException | TableNotFoundException e) {
            throw new PCJStorageException("Could not create a new PCJ named: " + pcjTableName, e);
        } finally {
            if (writer != null) {
                try {
                    writer.close();
                } catch (final MutationsRejectedException e) {
                    log.error("Mutations rejected while creating the PCJ table.", e);
                }
            }
        }
    }
}

Example 10 with PCJStorageException

use of org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.PCJStorageException in project incubator-rya by apache.

the class PcjTables method updateCardinality.

/**
 * Update the cardinality of a PCJ by a {@code delta}.
 *
 * @param accumuloConn - A connection to the Accumulo that hosts the PCJ table. (not null)
 * @param pcjTableName - The name of the PCJ table that will have its cardinality updated. (not null)
 * @param delta - How much the cardinality will change.
 * @throws PCJStorageException The cardinality could not be updated.
 */
private void updateCardinality(final Connector accumuloConn, final String pcjTableName, final long delta) throws PCJStorageException {
    checkNotNull(accumuloConn);
    checkNotNull(pcjTableName);
    ConditionalWriter conditionalWriter = null;
    try {
        conditionalWriter = accumuloConn.createConditionalWriter(pcjTableName, new ConditionalWriterConfig());
        boolean updated = false;
        while (!updated) {
            // Write the conditional update request to Accumulo.
            final long cardinality = getPcjMetadata(accumuloConn, pcjTableName).getCardinality();
            final ConditionalMutation mutation = makeUpdateCardinalityMutation(cardinality, delta);
            final ConditionalWriter.Result result = conditionalWriter.write(mutation);
            // Interpret the result.
            switch(result.getStatus()) {
                case ACCEPTED:
                    updated = true;
                    break;
                case REJECTED:
                    break;
                case UNKNOWN:
                    // We do not know if the mutation succeeded. At best, we
                    // can hope the metadata hasn't been updated
                    // since we originally fetched it and try again.
                    // Otherwise, continue forwards as if it worked. It's
                    // okay if this number is slightly off.
                    final long newCardinality = getPcjMetadata(accumuloConn, pcjTableName).getCardinality();
                    if (newCardinality != cardinality) {
                        updated = true;
                    }
                    break;
                case VIOLATED:
                    throw new PCJStorageException("The cardinality could not be updated because the commit violated a table constraint.");
                case INVISIBLE_VISIBILITY:
                    throw new PCJStorageException("The condition contains a visibility the updater can not satisfy.");
            }
        }
    } catch (AccumuloException | AccumuloSecurityException | TableNotFoundException e) {
        throw new PCJStorageException("Could not update the cardinality value of the PCJ Table named: " + pcjTableName, e);
    } finally {
        if (conditionalWriter != null) {
            conditionalWriter.close();
        }
    }
}