Examples with ProcessContinuation org.apache.beam.sdk.transforms.DoFn.ProcessContinuation used on opensource projects

Example 1 with ProcessContinuation

use of org.apache.beam.sdk.transforms.DoFn.ProcessContinuation in project beam by apache.

the class QueryChangeStreamAction method run.

/**
 * This method will dispatch a change stream query for the given partition, it delegate the
 * processing of the records to one of the corresponding action classes registered and it will
 * keep the state of the partition up to date in the Connector's metadata table.
 *
 * <p>The algorithm is as follows:
 *
 * <ol>
 *   <li>A change stream query for the partition is performed.
 *   <li>For each record, we check the type of the record and dispatch the processing to one of
 *       the actions registered.
 *   <li>If an {@link Optional} with a {@link ProcessContinuation#stop()} is returned from the
 *       actions, we stop processing and return.
 *   <li>Before returning we register a bundle finalizer callback to update the watermark of the
 *       partition in the metadata tables to the latest processed timestamp.
 *   <li>When a change stream query finishes successfully (no more records) we update the
 *       partition state to FINISHED.
 * </ol>
 *
 * There might be cases where due to a split at the exact end timestamp of a partition's change
 * stream query, this function could process a residual with an invalid timestamp. In this case,
 * the error is ignored and no work is done for the residual.
 *
 * @param partition the current partition being processed
 * @param tracker the restriction tracker of the {@link
 *     org.apache.beam.sdk.io.gcp.spanner.changestreams.dofn.ReadChangeStreamPartitionDoFn} SDF
 * @param receiver the output receiver of the {@link
 *     org.apache.beam.sdk.io.gcp.spanner.changestreams.dofn.ReadChangeStreamPartitionDoFn} SDF
 * @param watermarkEstimator the watermark estimator of the {@link
 *     org.apache.beam.sdk.io.gcp.spanner.changestreams.dofn.ReadChangeStreamPartitionDoFn} SDF
 * @param bundleFinalizer the bundle finalizer for {@link
 *     org.apache.beam.sdk.io.gcp.spanner.changestreams.dofn.ReadChangeStreamPartitionDoFn} SDF
 *     bundles
 * @return a {@link ProcessContinuation#stop()} if a record timestamp could not be claimed or if
 *     the partition processing has finished
 */
@SuppressWarnings("nullness")
@VisibleForTesting
public ProcessContinuation run(PartitionMetadata partition, RestrictionTracker<OffsetRange, Long> tracker, OutputReceiver<DataChangeRecord> receiver, ManualWatermarkEstimator<Instant> watermarkEstimator, BundleFinalizer bundleFinalizer) {
    final String token = partition.getPartitionToken();
    final Timestamp endTimestamp = partition.getEndTimestamp();
    /*
     * FIXME(b/202802422): Workaround until the backend is fixed.
     * The change stream API returns invalid argument if we try to use a child partition start
     * timestamp for a previously returned query. If we split at that exact time, we won't be able
     * to obtain the child partition on the residual restriction, since it will start at the child
     * partition start time.
     * To circumvent this, we always start querying one microsecond before the restriction start
     * time, and ignore any records that are before the restriction start time. This way the child
     * partition should be returned within the query.
     */
    final Timestamp restrictionStartTimestamp = Timestamp.ofTimeMicroseconds(tracker.currentRestriction().getFrom());
    final Timestamp previousStartTimestamp = Timestamp.ofTimeMicroseconds(TimestampConverter.timestampToMicros(restrictionStartTimestamp) - 1);
    final boolean isFirstRun = restrictionStartTimestamp.compareTo(partition.getStartTimestamp()) == 0;
    final Timestamp startTimestamp = isFirstRun ? restrictionStartTimestamp : previousStartTimestamp;
    try (Scope scope = TRACER.spanBuilder("QueryChangeStreamAction").setRecordEvents(true).startScopedSpan()) {
        TRACER.getCurrentSpan().putAttribute(PARTITION_ID_ATTRIBUTE_LABEL, AttributeValue.stringAttributeValue(token));
        // TODO: Potentially we can avoid this fetch, by enriching the runningAt timestamp when the
        // ReadChangeStreamPartitionDoFn#processElement is called
        final PartitionMetadata updatedPartition = Optional.ofNullable(partitionMetadataDao.getPartition(token)).map(partitionMetadataMapper::from).orElseThrow(() -> new IllegalStateException("Partition " + token + " not found in metadata table"));
        try (ChangeStreamResultSet resultSet = changeStreamDao.changeStreamQuery(token, startTimestamp, endTimestamp, partition.getHeartbeatMillis())) {
            while (resultSet.next()) {
                final List<ChangeStreamRecord> records = changeStreamRecordMapper.toChangeStreamRecords(updatedPartition, resultSet.getCurrentRowAsStruct(), resultSet.getMetadata());
                Optional<ProcessContinuation> maybeContinuation;
                for (final ChangeStreamRecord record : records) {
                    if (record.getRecordTimestamp().compareTo(restrictionStartTimestamp) < 0) {
                        continue;
                    }
                    if (record instanceof DataChangeRecord) {
                        maybeContinuation = dataChangeRecordAction.run(updatedPartition, (DataChangeRecord) record, tracker, receiver, watermarkEstimator);
                    } else if (record instanceof HeartbeatRecord) {
                        maybeContinuation = heartbeatRecordAction.run(updatedPartition, (HeartbeatRecord) record, tracker, watermarkEstimator);
                    } else if (record instanceof ChildPartitionsRecord) {
                        maybeContinuation = childPartitionsRecordAction.run(updatedPartition, (ChildPartitionsRecord) record, tracker, watermarkEstimator);
                    } else {
                        LOG.error("[" + token + "] Unknown record type " + record.getClass());
                        throw new IllegalArgumentException("Unknown record type " + record.getClass());
                    }
                    if (maybeContinuation.isPresent()) {
                        LOG.debug("[" + token + "] Continuation present, returning " + maybeContinuation);
                        bundleFinalizer.afterBundleCommit(Instant.now().plus(BUNDLE_FINALIZER_TIMEOUT), updateWatermarkCallback(token, watermarkEstimator));
                        return maybeContinuation.get();
                    }
                }
            }
            bundleFinalizer.afterBundleCommit(Instant.now().plus(BUNDLE_FINALIZER_TIMEOUT), updateWatermarkCallback(token, watermarkEstimator));
        } catch (SpannerException e) {
            if (isTimestampOutOfRange(e)) {
                LOG.debug("[" + token + "] query change stream is out of range for " + startTimestamp + " to " + endTimestamp + ", finishing stream");
            } else {
                throw e;
            }
        }
    }
    final long endMicros = TimestampConverter.timestampToMicros(endTimestamp);
    LOG.debug("[" + token + "] change stream completed successfully");
    if (tracker.tryClaim(endMicros)) {
        LOG.debug("[" + token + "] Finishing partition");
        partitionMetadataDao.updateToFinished(token);
        LOG.info("[" + token + "] Partition finished");
    }
    return ProcessContinuation.stop();
}

Example 2 with ProcessContinuation

use of org.apache.beam.sdk.transforms.DoFn.ProcessContinuation in project beam by apache.

the class ReadFromKafkaDoFnTest method testProcessElementWithEmptyPoll.

@Test
public void testProcessElementWithEmptyPoll() throws Exception {
    MockOutputReceiver receiver = new MockOutputReceiver();
    consumer.setNumOfRecordsPerPoll(-1);
    OffsetRangeTracker tracker = new OffsetRangeTracker(new OffsetRange(0L, Long.MAX_VALUE));
    ProcessContinuation result = dofnInstance.processElement(KafkaSourceDescriptor.of(topicPartition, null, null, null, null, null), tracker, null, (OutputReceiver) receiver);
    assertEquals(ProcessContinuation.resume(), result);
    assertTrue(receiver.getOutputs().isEmpty());
}

Example 3 with ProcessContinuation

use of org.apache.beam.sdk.transforms.DoFn.ProcessContinuation in project beam by apache.

the class ReadFromKafkaDoFnTest method testProcessElementWhenTopicPartitionIsStopped.

@Test
public void testProcessElementWhenTopicPartitionIsStopped() throws Exception {
    MockOutputReceiver receiver = new MockOutputReceiver();
    ReadFromKafkaDoFn<String, String> instance = new ReadFromKafkaDoFn(makeReadSourceDescriptor(consumer).toBuilder().setCheckStopReadingFn(new SerializableFunction<TopicPartition, Boolean>() {

        @Override
        public Boolean apply(TopicPartition input) {
            assertTrue(input.equals(topicPartition));
            return true;
        }
    }).build());
    consumer.setNumOfRecordsPerPoll(10);
    OffsetRangeTracker tracker = new OffsetRangeTracker(new OffsetRange(0L, Long.MAX_VALUE));
    ProcessContinuation result = instance.processElement(KafkaSourceDescriptor.of(topicPartition, null, null, null, null, null), tracker, null, (OutputReceiver) receiver);
    assertEquals(ProcessContinuation.stop(), result);
}

Example 4 with ProcessContinuation

use of org.apache.beam.sdk.transforms.DoFn.ProcessContinuation in project beam by apache.

the class ReadFromKafkaDoFnTest method testProcessElementWhenTopicPartitionIsRemoved.

@Test
public void testProcessElementWhenTopicPartitionIsRemoved() throws Exception {
    MockOutputReceiver receiver = new MockOutputReceiver();
    consumer.setRemoved();
    consumer.setNumOfRecordsPerPoll(10);
    OffsetRangeTracker tracker = new OffsetRangeTracker(new OffsetRange(0L, Long.MAX_VALUE));
    ProcessContinuation result = dofnInstance.processElement(KafkaSourceDescriptor.of(topicPartition, null, null, null, null, null), tracker, null, (OutputReceiver) receiver);
    assertEquals(ProcessContinuation.stop(), result);
}

Example 5 with ProcessContinuation

use of org.apache.beam.sdk.transforms.DoFn.ProcessContinuation in project beam by apache.

the class WatchTest method testPollingGrowthTrackerUsesElementTimestampIfNoWatermarkProvided.

@Test
public void testPollingGrowthTrackerUsesElementTimestampIfNoWatermarkProvided() throws Exception {
    Instant now = Instant.now();
    Watch.Growth<String, String, String> growth = Watch.growthOf(new Watch.Growth.PollFn<String, String>() {

        @Override
        public PollResult<String> apply(String element, Context c) throws Exception {
            // We specifically test an unsorted list.
            return PollResult.incomplete(Arrays.asList(TimestampedValue.of("d", now.plus(standardSeconds(4))), TimestampedValue.of("c", now.plus(standardSeconds(3))), TimestampedValue.of("a", now.plus(standardSeconds(1))), TimestampedValue.of("b", now.plus(standardSeconds(2)))));
        }
    }).withPollInterval(standardSeconds(10));
    WatchGrowthFn<String, String, String, Integer> growthFn = new WatchGrowthFn(growth, StringUtf8Coder.of(), SerializableFunctions.identity(), StringUtf8Coder.of());
    GrowthTracker<String, Integer> tracker = newPollingGrowthTracker();
    DoFn.ProcessContext context = mock(DoFn.ProcessContext.class);
    ManualWatermarkEstimator<Instant> watermarkEstimator = new WatermarkEstimators.Manual(BoundedWindow.TIMESTAMP_MIN_VALUE);
    ProcessContinuation processContinuation = growthFn.process(context, tracker, watermarkEstimator);
    assertEquals(now.plus(standardSeconds(1)), watermarkEstimator.currentWatermark());
    assertTrue(processContinuation.shouldResume());
}