Examples with AbstractFunction2 scala.runtime.AbstractFunction2 used on opensource projects

Example 1 with AbstractFunction2

use of scala.runtime.AbstractFunction2 in project samza by apache.

the class KafkaSystemAdmin method getSystemStreamPartitionCounts.

/**
 * Note! This method does not populate SystemStreamMetadata for each stream with real data.
 * Thus, this method should ONLY be used to get number of partitions for each stream.
 * It will throw NotImplementedException if anyone tries to access the actual metadata.
 * @param streamNames set of streams for which get the partitions counts
 * @param cacheTTL cache TTL if caching the data
 * @return a map, keyed on stream names. Number of partitions in SystemStreamMetadata is the output of this method.
 */
@Override
public Map<String, SystemStreamMetadata> getSystemStreamPartitionCounts(Set<String> streamNames, long cacheTTL) {
    // This optimization omits actual metadata for performance. Instead, we inject a dummy for all partitions.
    final SystemStreamMetadata.SystemStreamPartitionMetadata dummySspm = new SystemStreamMetadata.SystemStreamPartitionMetadata(null, null, null) {

        String msg = "getSystemStreamPartitionCounts does not populate SystemStreaMetadata info. Only number of partitions";

        @Override
        public String getOldestOffset() {
            throw new NotImplementedException(msg);
        }

        @Override
        public String getNewestOffset() {
            throw new NotImplementedException(msg);
        }

        @Override
        public String getUpcomingOffset() {
            throw new NotImplementedException(msg);
        }
    };
    ExponentialSleepStrategy strategy = new ExponentialSleepStrategy(DEFAULT_EXPONENTIAL_SLEEP_BACK_OFF_MULTIPLIER, DEFAULT_EXPONENTIAL_SLEEP_INITIAL_DELAY_MS, DEFAULT_EXPONENTIAL_SLEEP_MAX_DELAY_MS);
    Function1<ExponentialSleepStrategy.RetryLoop, Map<String, SystemStreamMetadata>> fetchMetadataOperation = new AbstractFunction1<ExponentialSleepStrategy.RetryLoop, Map<String, SystemStreamMetadata>>() {

        @Override
        public Map<String, SystemStreamMetadata> apply(ExponentialSleepStrategy.RetryLoop loop) {
            Map<String, SystemStreamMetadata> allMetadata = new HashMap<>();
            streamNames.forEach(streamName -> {
                Map<Partition, SystemStreamMetadata.SystemStreamPartitionMetadata> partitionMetadata = new HashMap<>();
                List<PartitionInfo> partitionInfos = threadSafeKafkaConsumer.execute(consumer -> consumer.partitionsFor(streamName));
                LOG.debug("Stream {} has partitions {}", streamName, partitionInfos);
                partitionInfos.forEach(partitionInfo -> partitionMetadata.put(new Partition(partitionInfo.partition()), dummySspm));
                allMetadata.put(streamName, new SystemStreamMetadata(streamName, partitionMetadata));
            });
            loop.done();
            return allMetadata;
        }
    };
    Map<String, SystemStreamMetadata> result = strategy.run(fetchMetadataOperation, new AbstractFunction2<Exception, ExponentialSleepStrategy.RetryLoop, BoxedUnit>() {

        @Override
        public BoxedUnit apply(Exception exception, ExponentialSleepStrategy.RetryLoop loop) {
            if (loop.sleepCount() < MAX_RETRIES_ON_EXCEPTION) {
                LOG.warn(String.format("Fetching systemstreampartition counts for: %s threw an exception. Retrying.", streamNames), exception);
            } else {
                LOG.error(String.format("Fetching systemstreampartition counts for: %s threw an exception.", streamNames), exception);
                loop.done();
                throw new SamzaException(exception);
            }
            return null;
        }
    }).get();
    LOG.info("SystemStream partition counts for system {}: {}", systemName, result);
    return result;
}

Example 2 with AbstractFunction2

use of scala.runtime.AbstractFunction2 in project samza by apache.

the class KafkaSystemAdmin method getSSPMetadata.

/**
 * Given a set of SystemStreamPartition, fetch metadata from Kafka for each
 * of them, and return a map from ssp to SystemStreamPartitionMetadata for
 * each of them. This method will return null for oldest and newest offsets
 * if a given SystemStreamPartition is empty. This method will block and
 * retry indefinitely until it gets a successful response from Kafka.
 * @param ssps a set of strings of SSP
 * @param retryBackoff retry backoff strategy
 * @return a map from ssp to sspMetadata which has offsets
 */
Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata> getSSPMetadata(Set<SystemStreamPartition> ssps, ExponentialSleepStrategy retryBackoff) {
    LOG.info("Fetching SSP metadata for: {}", ssps);
    List<TopicPartition> topicPartitions = ssps.stream().map(ssp -> new TopicPartition(ssp.getStream(), ssp.getPartition().getPartitionId())).collect(Collectors.toList());
    Function1<ExponentialSleepStrategy.RetryLoop, Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata>> fetchTopicPartitionMetadataOperation = new AbstractFunction1<ExponentialSleepStrategy.RetryLoop, Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata>>() {

        @Override
        public Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata> apply(ExponentialSleepStrategy.RetryLoop loop) {
            OffsetsMaps topicPartitionsMetadata = fetchTopicPartitionsMetadata(topicPartitions);
            Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata> sspToSSPMetadata = new HashMap<>();
            for (SystemStreamPartition ssp : ssps) {
                String oldestOffset = topicPartitionsMetadata.getOldestOffsets().get(ssp);
                String newestOffset = topicPartitionsMetadata.getNewestOffsets().get(ssp);
                String upcomingOffset = topicPartitionsMetadata.getUpcomingOffsets().get(ssp);
                sspToSSPMetadata.put(ssp, new SystemStreamMetadata.SystemStreamPartitionMetadata(oldestOffset, newestOffset, upcomingOffset));
            }
            loop.done();
            return sspToSSPMetadata;
        }
    };
    Function2<Exception, ExponentialSleepStrategy.RetryLoop, BoxedUnit> onExceptionRetryOperation = new AbstractFunction2<Exception, ExponentialSleepStrategy.RetryLoop, BoxedUnit>() {

        @Override
        public BoxedUnit apply(Exception exception, ExponentialSleepStrategy.RetryLoop loop) {
            if (loop.sleepCount() < MAX_RETRIES_ON_EXCEPTION) {
                LOG.warn(String.format("Fetching SSP metadata for: %s threw an exception. Retrying.", ssps), exception);
            } else {
                LOG.error(String.format("Fetching SSP metadata for: %s threw an exception.", ssps), exception);
                loop.done();
                throw new SamzaException(exception);
            }
            return null;
        }
    };
    Function0<Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata>> fallbackOperation = new AbstractFunction0<Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata>>() {

        @Override
        public Map<SystemStreamPartition, SystemStreamMetadata.SystemStreamPartitionMetadata> apply() {
            throw new SamzaException("Failed to get SSP metadata");
        }
    };
    return retryBackoff.run(fetchTopicPartitionMetadataOperation, onExceptionRetryOperation).getOrElse(fallbackOperation);
}