hit-lacus commented on a change in pull request #680: KYLIN-4035 Calculate column cardinality by using spark engine URL: https://github.com/apache/kylin/pull/680#discussion_r294071741
########## File path: engine-spark/src/main/java/org/apache/kylin/engine/spark/SparkColumnCardinality.java ########## @@ -0,0 +1,158 @@ +/* + * 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.kylin.engine.spark; + +import org.apache.commons.cli.Option; +import org.apache.commons.cli.OptionBuilder; +import org.apache.commons.cli.Options; +import org.apache.hadoop.fs.Path; +import org.apache.hadoop.io.IntWritable; +import org.apache.hadoop.io.LongWritable; +import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat; +import org.apache.kylin.common.util.AbstractApplication; +import org.apache.kylin.common.util.Bytes; +import org.apache.kylin.common.util.HadoopUtil; +import org.apache.kylin.common.util.OptionsHelper; +import org.apache.kylin.engine.mr.common.BatchConstants; +import org.apache.kylin.measure.hllc.HLLCounter; +import org.apache.spark.SparkConf; +import org.apache.spark.api.java.JavaPairRDD; +import org.apache.spark.api.java.JavaRDD; +import org.apache.spark.api.java.JavaSparkContext; +import org.apache.spark.api.java.function.PairFlatMapFunction; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import scala.Tuple2; + +import java.io.Serializable; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.Iterator; +import java.util.List; +import java.util.Map; + +public class SparkColumnCardinality extends AbstractApplication implements Serializable { + protected static final Logger logger = LoggerFactory.getLogger(SparkColumnCardinality.class); + + public static final Option OPTION_TABLE_NAME = OptionBuilder.withArgName(BatchConstants.ARG_TABLE_NAME).hasArg() + .isRequired(true).withDescription("Table Name").create(BatchConstants.ARG_TABLE_NAME); + public static final Option OPTION_OUTPUT = OptionBuilder.withArgName(BatchConstants.ARG_OUTPUT).hasArg() + .isRequired(true).withDescription("Output").create(BatchConstants.ARG_OUTPUT); + public static final Option OPTION_PRJ = OptionBuilder.withArgName(BatchConstants.ARG_PROJECT).hasArg() + .isRequired(true).withDescription("Project name").create(BatchConstants.ARG_PROJECT); + public static final Option OPTION_COLUMN_COUNT = OptionBuilder.withArgName(BatchConstants.CFG_OUTPUT_COLUMN).hasArg() + .isRequired(true).withDescription("column count").create(BatchConstants.CFG_OUTPUT_COLUMN); + + private Options options; + + public SparkColumnCardinality() { + options = new Options(); + options.addOption(OPTION_TABLE_NAME); + options.addOption(OPTION_OUTPUT); + options.addOption(OPTION_PRJ); + options.addOption(OPTION_COLUMN_COUNT); + } + + @Override + protected Options getOptions() { + return options; + } + + @Override + protected void execute(OptionsHelper optionsHelper) throws Exception { + String tableName = optionsHelper.getOptionValue(OPTION_TABLE_NAME); + String output = optionsHelper.getOptionValue(OPTION_OUTPUT); + int columnCnt = Integer.valueOf(optionsHelper.getOptionValue(OPTION_COLUMN_COUNT)); + + Class[] kryoClassArray = new Class[]{Class.forName("scala.reflect.ClassTag$$anon$1"), + Class.forName("org.apache.kylin.engine.mr.steps.SelfDefineSortableKey")}; + + SparkConf conf = new SparkConf().setAppName("Calculate table:" + tableName); + //set spark.sql.catalogImplementation=hive, If it is not set, SparkSession can't read hive metadata, and throw "org.apache.spark.sql.AnalysisException" + conf.set("spark.sql.catalogImplementation", "hive"); + //serialization conf + conf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer"); + conf.set("spark.kryo.registrator", "org.apache.kylin.engine.spark.KylinKryoRegistrator"); + conf.set("spark.kryo.registrationRequired", "true").registerKryoClasses(kryoClassArray); + + KylinSparkJobListener jobListener = new KylinSparkJobListener(); + try (JavaSparkContext sc = new JavaSparkContext(conf)) { + sc.sc().addSparkListener(jobListener); + HadoopUtil.deletePath(sc.hadoopConfiguration(), new Path(output)); + // table will be loaded by spark sql, so isSequenceFile set false + final JavaRDD<String[]> recordRDD = SparkUtil.hiveRecordInputRDD(false, sc, null, tableName); + JavaPairRDD<Integer, Long> resultRdd = recordRDD.mapPartitionsToPair(new BuildHllCounter()) + .reduceByKey((x, y) -> { + x.merge(y); + return x; + }) + .mapToPair(record -> { + return new Tuple2<>(record._1, record._2.getCountEstimate()); + }) + .sortByKey(true, 1); + + if (resultRdd.count() == 0) { Review comment: Both `count` and `saveAsNewAPIHadoopFile` are action of `RDD`, I think here `resultRdd` should be cached to avoid recompute, am I right? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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