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ASF GitHub Bot commented on DRILL-4779: --------------------------------------- Github user paul-rogers commented on a diff in the pull request: https://github.com/apache/drill/pull/1027#discussion_r150081972 --- Diff: contrib/storage-kafka/src/main/java/org/apache/drill/exec/store/kafka/KafkaRecordReader.java --- @@ -0,0 +1,178 @@ +/** + * 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.drill.exec.store.kafka; + +import static org.apache.drill.exec.store.kafka.DrillKafkaConfig.DRILL_KAFKA_POLL_TIMEOUT; + +import java.util.Collection; +import java.util.Iterator; +import java.util.List; +import java.util.Set; +import java.util.concurrent.TimeUnit; + +import org.apache.drill.common.exceptions.ExecutionSetupException; +import org.apache.drill.common.expression.SchemaPath; +import org.apache.drill.exec.ExecConstants; +import org.apache.drill.exec.ops.FragmentContext; +import org.apache.drill.exec.ops.OperatorContext; +import org.apache.drill.exec.physical.impl.OutputMutator; +import org.apache.drill.exec.store.AbstractRecordReader; +import org.apache.drill.exec.store.kafka.KafkaSubScan.KafkaSubScanSpec; +import org.apache.drill.exec.store.kafka.decoders.MessageReader; +import org.apache.drill.exec.store.kafka.decoders.MessageReaderFactory; +import org.apache.drill.exec.util.Utilities; +import org.apache.drill.exec.vector.complex.impl.VectorContainerWriter; +import org.apache.kafka.clients.consumer.ConsumerRecord; +import org.apache.kafka.clients.consumer.ConsumerRecords; +import org.apache.kafka.clients.consumer.KafkaConsumer; +import org.apache.kafka.common.TopicPartition; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.google.common.base.Stopwatch; +import com.google.common.collect.Lists; +import com.google.common.collect.Sets; +public class KafkaRecordReader extends AbstractRecordReader { + private static final Logger logger = LoggerFactory.getLogger(KafkaRecordReader.class); + public static final long DEFAULT_MESSAGES_PER_BATCH = 4000; + + private VectorContainerWriter writer; + private MessageReader messageReader; + + private boolean unionEnabled; + private KafkaConsumer<byte[], byte[]> kafkaConsumer; + private KafkaStoragePlugin plugin; + private KafkaSubScanSpec subScanSpec; + private long kafkaPollTimeOut; + private long endOffset; + + private long currentOffset; + private long totalFetchTime = 0; + + private List<TopicPartition> partitions; + private final boolean enableAllTextMode; + private final boolean readNumbersAsDouble; + + private Iterator<ConsumerRecord<byte[], byte[]>> messageIter; + + public KafkaRecordReader(KafkaSubScan.KafkaSubScanSpec subScanSpec, List<SchemaPath> projectedColumns, + FragmentContext context, KafkaStoragePlugin plugin) { + setColumns(projectedColumns); + this.enableAllTextMode = context.getOptions().getOption(ExecConstants.KAFKA_ALL_TEXT_MODE).bool_val; + this.readNumbersAsDouble = context.getOptions() + .getOption(ExecConstants.KAFKA_READER_READ_NUMBERS_AS_DOUBLE).bool_val; + this.unionEnabled = context.getOptions().getOption(ExecConstants.ENABLE_UNION_TYPE); + this.plugin = plugin; + this.subScanSpec = subScanSpec; + this.endOffset = subScanSpec.getEndOffset(); + this.kafkaPollTimeOut = Long.valueOf(plugin.getConfig().getDrillKafkaProps().getProperty(DRILL_KAFKA_POLL_TIMEOUT)); + } + + @Override + protected Collection<SchemaPath> transformColumns(Collection<SchemaPath> projectedColumns) { --- End diff -- Preparing columns is really quite difficult with many cases to handle. Drill appears to allow projection of the form `a.b`, `a.c` which means that `a` is a map and we wish to project just `b` and `c` from `a`. As it turns out, there is an active project to replace the ad-hoc projection logic in each reader with a common, complete implementation. That work may be ready by Drill 1.13, so whatever is done here is temporary. Finally, the code checks for a star query and includes the star column. But, a star query occurs only when the one and only field is the wildcard (`*`). So, the transform for a star query would seem to be a no-op. Finally, a `SELECT COUNT(*)` query will provide an empty projection list, which this code must handle, if it does not already do so. > Kafka storage plugin support > ---------------------------- > > Key: DRILL-4779 > URL: https://issues.apache.org/jira/browse/DRILL-4779 > Project: Apache Drill > Issue Type: New Feature > Components: Storage - Other > Affects Versions: 1.11.0 > Reporter: B Anil Kumar > Assignee: B Anil Kumar > Labels: doc-impacting > Fix For: 1.12.0 > > > Implement Kafka storage plugin will enable the strong SQL support for Kafka. > Initially implementation can target for supporting json and avro message types -- This message was sent by Atlassian JIRA (v6.4.14#64029)