sql/streaming/JavaStructuredKerberizedKafkaWordCount.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.examples.sql.streaming;
0019
0020 import org.apache.kafka.common.security.auth.SecurityProtocol;
0021 import org.apache.spark.api.java.function.FlatMapFunction;
0022 import org.apache.spark.sql.Dataset;
0023 import org.apache.spark.sql.Encoders;
0024 import org.apache.spark.sql.Row;
0025 import org.apache.spark.sql.SparkSession;
0026 import org.apache.spark.sql.streaming.StreamingQuery;
0027
0028 import java.util.Arrays;
0029
0030 /**
0031  * Consumes messages from one or more topics in Kafka and does wordcount.
0032  * Usage: JavaStructuredKerberizedKafkaWordCount <bootstrap-servers> <subscribe-type> <topics>
0033  *   <bootstrap-servers> The Kafka "bootstrap.servers" configuration. A
0034  *   comma-separated list of host:port.
0035  *   <subscribe-type> There are three kinds of type, i.e. 'assign', 'subscribe',
0036  *   'subscribePattern'.
0037  *   |- <assign> Specific TopicPartitions to consume. Json string
0038  *   |  {"topicA":[0,1],"topicB":[2,4]}.
0039  *   |- <subscribe> The topic list to subscribe. A comma-separated list of
0040  *   |  topics.
0041  *   |- <subscribePattern> The pattern used to subscribe to topic(s).
0042  *   |  Java regex string.
0043  *   |- Only one of "assign, "subscribe" or "subscribePattern" options can be
0044  *   |  specified for Kafka source.
0045  *   <topics> Different value format depends on the value of 'subscribe-type'.
0046  *
0047  * Example:
0048  *   Yarn client:
0049  *    $ bin/run-example --files ${jaas_path}/kafka_jaas.conf,${keytab_path}/kafka.service.keytab \
0050  *      --driver-java-options "-Djava.security.auth.login.config=${path}/kafka_driver_jaas.conf" \
0051  *      --conf \
0052  *      "spark.executor.extraJavaOptions=-Djava.security.auth.login.config=./kafka_jaas.conf" \
0053  *      --master yarn
0054  *      sql.streaming.JavaStructuredKerberizedKafkaWordCount broker1-host:port,broker2-host:port \
0055  *      subscribe topic1,topic2
0056  *   Yarn cluster:
0057  *    $ bin/run-example --files \
0058  *      ${jaas_path}/kafka_jaas.conf,${keytab_path}/kafka.service.keytab,${krb5_path}/krb5.conf \
0059  *      --driver-java-options \
0060  *      "-Djava.security.auth.login.config=./kafka_jaas.conf \
0061  *      -Djava.security.krb5.conf=./krb5.conf" \
0062  *      --conf \
0063  *      "spark.executor.extraJavaOptions=-Djava.security.auth.login.config=./kafka_jaas.conf" \
0064  *      --master yarn --deploy-mode cluster \
0065  *      sql.streaming.JavaStructuredKerberizedKafkaWordCount broker1-host:port,broker2-host:port \
0066  *      subscribe topic1,topic2
0067  *
0068  * kafka_jaas.conf can manually create, template as:
0069  *   KafkaClient {
0070  *     com.sun.security.auth.module.Krb5LoginModule required
0071  *     keyTab="./kafka.service.keytab"
0072  *     useKeyTab=true
0073  *     storeKey=true
0074  *     useTicketCache=false
0075  *     serviceName="kafka"
0076  *     principal="kafka/host@EXAMPLE.COM";
0077  *   };
0078  * kafka_driver_jaas.conf (used by yarn client) and kafka_jaas.conf are basically the same
0079  * except for some differences at 'keyTab'. In kafka_driver_jaas.conf, 'keyTab' should be
0080  * "${keytab_path}/kafka.service.keytab".
0081  * In addition, for IBM JVMs, please use 'com.ibm.security.auth.module.Krb5LoginModule'
0082  * instead of 'com.sun.security.auth.module.Krb5LoginModule'.
0083  *
0084  * Note that this example uses SASL_PLAINTEXT for simplicity; however,
0085  * SASL_PLAINTEXT has no SSL encryption and likely be less secure. Please consider
0086  * using SASL_SSL in production.
0087  */
0088 public final class JavaStructuredKerberizedKafkaWordCount {
0089   public static void main(String[] args) throws Exception {
0090     if (args.length < 3) {
0091       System.err.println("Usage: JavaStructuredKerberizedKafkaWordCount <bootstrap-servers> " +
0092         "<subscribe-type> <topics>");
0093       System.exit(1);
0094     }
0095
0096     String bootstrapServers = args[0];
0097     String subscribeType = args[1];
0098     String topics = args[2];
0099
0100     SparkSession spark = SparkSession
0101       .builder()
0102       .appName("JavaStructuredKerberizedKafkaWordCount")
0103       .getOrCreate();
0104
0105     // Create DataSet representing the stream of input lines from kafka
0106     Dataset<String> lines = spark
0107       .readStream()
0108       .format("kafka")
0109       .option("kafka.bootstrap.servers", bootstrapServers)
0110       .option(subscribeType, topics)
0111       .option("kafka.security.protocol", SecurityProtocol.SASL_PLAINTEXT.name)
0112       .load()
0113       .selectExpr("CAST(value AS STRING)")
0114       .as(Encoders.STRING());
0115
0116     // Generate running word count
0117     Dataset<Row> wordCounts = lines.flatMap(
0118       (FlatMapFunction<String, String>) x -> Arrays.asList(x.split(" ")).iterator(),
0119       Encoders.STRING()).groupBy("value").count();
0120
0121     // Start running the query that prints the running counts to the console
0122     StreamingQuery query = wordCounts.writeStream()
0123       .outputMode("complete")
0124       .format("console")
0125       .start();
0126
0127     query.awaitTermination();
0128   }
0129 }