npawar commented on a change in pull request #5934: URL: https://github.com/apache/incubator-pinot/pull/5934#discussion_r481519977
########## File path: pinot-core/src/main/java/org/apache/pinot/core/segment/processing/framework/SegmentReducer.java ########## @@ -0,0 +1,151 @@ +/** + * 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.pinot.core.segment.processing.framework; + +import java.io.File; +import java.io.IOException; +import java.util.Iterator; +import org.apache.avro.file.DataFileWriter; +import org.apache.avro.generic.GenericData; +import org.apache.avro.generic.GenericDatumWriter; +import org.apache.pinot.core.segment.processing.collector.Collector; +import org.apache.pinot.core.segment.processing.collector.CollectorFactory; +import org.apache.pinot.core.segment.processing.utils.SegmentProcessorUtils; +import org.apache.pinot.spi.data.Schema; +import org.apache.pinot.spi.data.readers.GenericRow; +import org.apache.pinot.spi.data.readers.RecordReader; +import org.apache.pinot.spi.data.readers.RecordReaderFactory; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +/** + * Reducer phase of the SegmentProcessorFramework + * Reads the avro files in the input directory and creates output avro files in the reducer output directory. + * The avro files in the input directory are expected to contain data for only 1 partition + * Performs operations on that partition data as follows: + * - concatenation/rollup of records + * - split + * - TODO: dedup + */ +public class SegmentReducer { + + private static final Logger LOGGER = LoggerFactory.getLogger(SegmentReducer.class); + private static final int MAX_RECORDS_TO_COLLECT = 5_000_000; + + private final File _reducerInputDir; + private final File _reducerOutputDir; + + private final String _reducerId; + private final Schema _pinotSchema; + private final org.apache.avro.Schema _avroSchema; + private final Collector _collector; + private final int _numRecordsPerPart; + + public SegmentReducer(String reducerId, File reducerInputDir, SegmentReducerConfig reducerConfig, + File reducerOutputDir) { + _reducerInputDir = reducerInputDir; + _reducerOutputDir = reducerOutputDir; + + _reducerId = reducerId; + _pinotSchema = reducerConfig.getPinotSchema(); + _avroSchema = SegmentProcessorUtils.convertPinotSchemaToAvroSchema(_pinotSchema); + _collector = CollectorFactory.getCollector(reducerConfig.getCollectorConfig(), _pinotSchema); + _numRecordsPerPart = reducerConfig.getNumRecordsPerPart(); + LOGGER.info("Initialized reducer with id: {}, input dir: {}, output dir: {}, collector: {}, numRecordsPerPart: {}", + _reducerId, _reducerInputDir, _reducerOutputDir, _collector.getClass(), _numRecordsPerPart); + } + + /** + * Reads the avro files in the input directory. + * Performs configured operations and outputs to other avro file(s) in the reducer output directory. + */ + public void reduce() + throws Exception { + + int part = 0; + for (File inputFile : _reducerInputDir.listFiles()) { + + RecordReader avroRecordReader = RecordReaderFactory + .getRecordReaderByClass("org.apache.pinot.plugin.inputformat.avro.AvroRecordReader", inputFile, + _pinotSchema.getColumnNames(), null); + + while (avroRecordReader.hasNext()) { + GenericRow next = avroRecordReader.next(); + + // Aggregations + _collector.collect(next); + + // Exceeded max records allowed to collect. Flush + if (_collector.size() == MAX_RECORDS_TO_COLLECT) { Review comment: `Should we use _numRecordsPerPart here so that once the collector collects enough records, we flush them` - I had initially done it this way. But then I noticed while testing, that if user sets a very low numRecordsPerPart, we will aggregate less and flush very frequently. Having a bigger MAX_RECORDS_TO_COLLECT allows for more aggregation ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
