tencent cloud

Scenario Description

Data in Kafka can be collected through Flume and stored in Hive.

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 Flume 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 hive_kafka.properties.

   vim hive_kafka.properties
   agent.sources = kafka_source
   agent.channels = mem_channel
   agent.sinks = hive_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.hive_sink.channel = mem_channel
   agent.sinks.hive_sink.type = hive
   agent.sinks.hive_sink.hive.metastore = thrift://172.16.32.51:7004
   agent.sinks.hive_sink.hive.database = default
   agent.sinks.hive_sink.hive.table = weblogs
   agent.sinks.hive_sink.hive.partition = asia,india,%y-%m-%d-%H-%M
   agent.sinks.hive_sink.useLocalTimeStamp = true
   agent.sinks.hive_sink.round = true
   agent.sinks.hive_sink.roundValue = 10
   agent.sinks.hive_sink.roundUnit = minute
   agent.sinks.hive_sink.serializer = DELIMITED
   agent.sinks.hive_sink.serializer.delimiter = ","
   agent.sinks.hive_sink.serializer.serdeSeparator = ','
   agent.sinks.hive_sink.serializer.fieldnames =id,msg
   # 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 = 100000
   

You can confirm Hive Metastore in the following way:

grep "hive.metastore.uris" -C 2 /usr/local/service/hive/conf/hive-site.xml

<property>
<name>hive.metastore.uris</name>
<value>thrift://172.16.32.51:7004</value>
</property>

2. Create a Hive table.

   create table weblogs ( id int , msg string )
   partitioned by (continent string, country string, time string)
   clustered by (id) into 5 buckets
   stored as orc TBLPROPERTIES ('transactional'='true');
   

Note：

All the following conditions must be met: it must be a table with partitions and buckets, the storage format is ORC, and TBLPROPERTIES ('transactional'='true') is set.
3. Enable the Hive transaction.
In the console, add the following configuration items to hive-site.xml.

<property>
<name>hive.support.concurrency</name>
<value>true</value>
</property>
<property>
<name>hive.exec.dynamic.partition.mode</name>
<value>nonstrict</value>
</property>
<property>
<name>hive.txn.manager</name>
<value>org.apache.hadoop.hive.ql.lockmgr.DbTxnManager</value>
</property>
<property>
<name>hive.compactor.initiator.on</name>
<value>true</value>
</property>
<property>
<name>hive.compactor.worker.threads</name>
<value>1</value>
</property>
<property>
<name>hive.enforce.bucketing</name>
<value>true</value>
</property>

Note：

After the configuration is distributed and Hive is restarted, the hadoop-hive log will prompt that the Metastore cannot be connected to. Please ignore this error. Because of the startup order of the processes, Metastore will be started before HiveServer2.
4. Copy hive-hcatalog-streaming-xxx.jar of Hive to the lib directory of Flume.

cp -ra /usr/local/service/hive/hcatalog/share/hcatalog/hive-hcatalog-streaming-2.3.3.jar /usr/local/service/flume/lib/

5. Run Flume.

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

6. Run the Kafka producer.

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

Test

• Enter information on the client of the Kafka producer and press Enter.
• Check whether there is corresponding data in the Hive table.

Reference Documentation

• Hive Sink Configuration Description
• Hive Log Configuration Description