Scenario Description

Data in Kafka can be collected through Flume and stored in HDFS or COS.

Preparations for Development

• As this job requires access to CKafka, you need to create a CKafka instance first. For more information, please see CKafka.
• Confirm that you have activated Tencent Cloud and created an EMR cluster. When creating the EMR cluster, you need to select the Spark component on the software configuration page.

Using the Kafka Toolkit in the EMR Cluster

First, you need to check the private IP and port number of CKafka. Log in to the CKafka Console, select the CKafka instance you want to use, and view its private IP as $kafkaIP in the basic information section, and the port number is generally 9092 by default. Create a topic named kafka_test on the topic management page.

Configuring Flume

1. Create the Flume configuration file kafka.properties.

   vim kafka.properties
   agent.sources = kafka_source
   agent.channels = mem_channel
   agent.sinks = hdfs_sink
   # The following code is used to configure the source
   agent.sources.kafka_source.type = org.apache.flume.source.kafka.KafkaSource
   agent.sources.kafka_source.channels = mem_channel
   agent.sources.kafka_source.batchSize = 5000
   agent.sources.kafka_source.kafka.bootstrap.servers = $kafkaIP:9092
   agent.sources.kafka_source.kafka.topics = kafka_test
   # The following code is used to configure the sink
   agent.sinks.hdfs_sink.type = hdfs
   agent.sinks.hdfs_sink.channel = mem_channel
   agent.sinks.hdfs_sink.hdfs.path = /data/flume/kafka/%Y%m%d (or cosn://bucket/xxx)
   agent.sinks.hdfs_sink.hdfs.rollSize = 0  
   agent.sinks.hdfs_sink.hdfs.rollCount = 0  
   agent.sinks.hdfs_sink.hdfs.rollInterval = 3600  
   agent.sinks.hdfs_sink.hdfs.threadsPoolSize = 30
   agent.sinks.hdfs_sink.hdfs.fileType=DataStream    
   agent.sinks.hdfs_sink.hdfs.useLocalTimeStamp=true
   agent.sinks.hdfs_sink.hdfs.writeFormat=Text
   # The following code is used to configure the channel
   agent.channels.mem_channel.type = memory
   agent.channels.mem_channel.capacity = 100000
   agent.channels.mem_channel.transactionCapacity = 10000

2. Run Flume.

   ./bin/flume-ng agent --conf ./conf/ -f kafka.properties -n agent -Dflume.root.logger=INFO,console

3. Run Kafka producer.

   [hadoop@172 kafka]$ ./bin/kafka-console-producer.sh --broker-list $kafkaIP:9092 --topic kafka_test
   test
   hello

Test

• Enter information on the client of the Kafka producer and press Enter.
• Check whether the corresponding directory and file hadoop fs -ls /data/flume/kafka/ have been generated in HDFS.

Reference Documentation

Kafka Source Configuration Description