| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.rya.streams.kafka; |
| |
| import static java.util.Objects.requireNonNull; |
| |
| import java.util.Properties; |
| |
| import org.apache.kafka.clients.consumer.ConsumerConfig; |
| import org.apache.kafka.streams.KafkaStreams; |
| import org.apache.kafka.streams.StreamsConfig; |
| import org.apache.kafka.streams.processor.TopologyBuilder; |
| import org.apache.rya.api.function.projection.RandomUUIDFactory; |
| import org.apache.rya.streams.api.entity.StreamsQuery; |
| import org.apache.rya.streams.kafka.topology.TopologyBuilderFactory; |
| import org.apache.rya.streams.kafka.topology.TopologyBuilderFactory.TopologyBuilderException; |
| import org.apache.rya.streams.kafka.topology.TopologyFactory; |
| import org.openrdf.query.MalformedQueryException; |
| |
| import edu.umd.cs.findbugs.annotations.DefaultAnnotation; |
| import edu.umd.cs.findbugs.annotations.NonNull; |
| |
| /** |
| * Creates {@link KafkaStreams} objects that are able to process {@link StreamsQuery}s |
| * using a single thread of execution starting from the earliest point in within the |
| * input topic. The Application ID used by the client is based on the Query ID of the |
| * query that is being executed so that this job may resume where it left off if it |
| * is stopped. |
| */ |
| @DefaultAnnotation(NonNull.class) |
| public class SingleThreadKafkaStreamsFactory implements KafkaStreamsFactory { |
| |
| private final TopologyBuilderFactory topologyFactory = new TopologyFactory(); |
| |
| private final String bootstrapServersConfig; |
| |
| /** |
| * Constructs an instance of {@link SingleThreadKafkaStreamsFactory}. |
| * |
| * @param bootstrapServersConfig - Configures which Kafka cluster the jobs will interact with. (not null) |
| */ |
| public SingleThreadKafkaStreamsFactory(final String bootstrapServersConfig) { |
| this.bootstrapServersConfig = requireNonNull(bootstrapServersConfig); |
| } |
| |
| @Override |
| public KafkaStreams make(final String ryaInstance, final StreamsQuery query) throws KafkaStreamsFactoryException { |
| requireNonNull(ryaInstance); |
| requireNonNull(query); |
| |
| // Setup the Kafka Stream program. |
| final Properties streamsProps = new Properties(); |
| |
| // Configure the Kafka servers that will be talked to. |
| streamsProps.setProperty(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServersConfig); |
| |
| // Use the Query ID as the Application ID to ensure we resume where we left off the last time this command was run. |
| streamsProps.put(StreamsConfig.APPLICATION_ID_CONFIG, "RyaStreams-Query-" + query.getQueryId()); |
| |
| // Always start at the beginning of the input topic. |
| streamsProps.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest"); |
| |
| // Setup the topology that processes the Query. |
| final String statementsTopic = KafkaTopics.statementsTopic(ryaInstance); |
| final String resultsTopic = KafkaTopics.queryResultsTopic(ryaInstance, query.getQueryId()); |
| |
| try { |
| final TopologyBuilder topologyBuilder = topologyFactory.build(query.getSparql(), statementsTopic, resultsTopic, new RandomUUIDFactory()); |
| return new KafkaStreams(topologyBuilder, new StreamsConfig(streamsProps)); |
| } catch (final MalformedQueryException | TopologyBuilderException e) { |
| throw new KafkaStreamsFactoryException("Could not create a KafkaStreams processing topology for query " + query.getQueryId(), e); |
| } |
| } |
| } |