kafka写入hdfs

2021-12-16 12:38:00

碰到的问题

　　（1）线程操作问题，因为单机节点，代码加锁就好了，后续再写

　　（2）消费者写hdfs的时候以流的形式写入，但是什么时候关闭流就是一个大问题了，这里引入了 fsDataOutputStream.hsync();

 hsync  保证 hdfs在写数据的时候被新的reader读到，保证数据被datanode持久化

生产者

 package com.xuliugen.kafka.demo;

 import org.apache.kafka.clients.producer.KafkaProducer;

 import org.apache.kafka.clients.producer.ProducerRecord;

 import java.util.Properties;

 public class ProducerDemo {

     // Topic

     private static final String topic = "tangsonghuai";

     public static void main(String[] args) throws Exception {

         Properties props = new Properties();

         props.put("bootstrap.servers", "192.168.15.140:9092");

         props.put("acks", "0");

         props.put("group.id", "1111");

         props.put("retries", "0");

         props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");

         props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

         //生产者实例

         KafkaProducer producer = new KafkaProducer(props);

         int i = 1;

         // 发送业务消息

         // 读取文件 读取内存数据库 读socket端口

         while (i<50) {

             Thread.sleep(100);

             producer.send(new ProducerRecord<String, String>(topic, "key:" + i, "value:" + i));

             System.out.println("key:" + i + " " + "value:" + i);

             i++;

         }

     }

 }

消费者

 package com.xuliugen.kafka.demo;

 import org.apache.hadoop.conf.Configuration;

 import org.apache.hadoop.fs.FSDataOutputStream;

 import org.apache.hadoop.fs.FileSystem;

 import org.apache.hadoop.fs.Path;

 import org.apache.hadoop.io.IOUtils;

 import org.apache.kafka.clients.consumer.ConsumerRecord;

 import org.apache.kafka.clients.consumer.ConsumerRecords;

 import org.apache.kafka.clients.consumer.KafkaConsumer;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import java.io.ByteArrayInputStream;

 import java.io.IOException;

 import java.net.URI;

 import java.util.*;

 public class ConsumerDemo {

     private static final Logger logger = LoggerFactory.getLogger(ConsumerDemo.class);

     private static final String topic = "tangsonghuai";

     public static void main(String[] args) throws IOException {

         Properties props = new Properties();

         props.put("bootstrap.servers", "192.168.15.140:9092");

         props.put("group.id", "1111");

         props.put("enable.auto.commit", "true");

         props.put("auto.commit.interval.ms", "1000");

         props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

         props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

         KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(props);

         consumer.subscribe(Arrays.asList(topic));

         int i = 0;

         String uri = "hdfs://192.168.15.140:9000/";

         Configuration configuration = new Configuration();

         configuration.set("dfs.client.block.write.replace-datanode-on-failure.policy", "NEVER");

         FileSystem fs = FileSystem.get(URI.create(uri), configuration);

         final String pathString = "/d1/tangsonghuai";

         final FSDataOutputStream fsDataOutputStream = fs.append(new Path(pathString));

         while (true) {

             ConsumerRecords<String, String> records = consumer.poll(1000);

             for (ConsumerRecord<String, String> record : records) {

                 System.out.printf("offset = %d, key = %s, value = %s%n", record.offset(), record.key(), record.value());

 //                HashMap<String, String> hmap= new HashMap<String, String>();

 //                hmap.put(record.key(),record.value());

                 fsDataOutputStream.write((record.offset()+","+record.key() + "," + record.value()+"\n").getBytes());

                 fsDataOutputStream.hsync();

                 i++;

                 if (i == 70) {

                     fsDataOutputStream.close();

                     consumer.close();

                 }

 //                IOUtils.copyBytes(new ByteArrayInputStream(record.value().getBytes()),

 //                        fsDataOutputStream,configuration, true);

             }

         }

     }

 }

pom.xml

 <?xml version="1.0" encoding="UTF-8"?>

 <project xmlns="http://maven.apache.org/POM/4.0.0"

          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

     <modelVersion>4.0.0</modelVersion>

     <groupId>com.xuliugen.kafka</groupId>

     <artifactId>kafka.demo</artifactId>

     <version>1.0-SNAPSHOT</version>

     <dependencies>

         <dependency>

             <groupId>org.apache.kafka</groupId>

             <artifactId>kafka-clients</artifactId>

             <version>2.0.0</version>

         </dependency>

         <dependency>

             <groupId>org.slf4j</groupId>

             <artifactId>slf4j-log4j12</artifactId>

             <version>1.7.12</version>

         </dependency>

         <dependency>

             <groupId>org.slf4j</groupId>

             <artifactId>slf4j-api</artifactId>

             <version>1.7.12</version>

         </dependency>

         <!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-common -->

         <dependency>

             <groupId>org.apache.hadoop</groupId>

             <artifactId>hadoop-common</artifactId>

             <version>2.8.5</version>

         </dependency>

         <!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-hdfs -->

         <dependency>

             <groupId>org.apache.hadoop</groupId>

             <artifactId>hadoop-hdfs</artifactId>

             <version>2.8.5</version>

         </dependency>

     </dependencies>

 </project>

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