在Kafka消费者中查看相应数据。
时间: 2023-12-17 19:02:48 浏览: 27
你好!谢谢你的问题。关于在Kafka消费者中查看相应数据,我可以给你一些建议。你需要在消费者代码中写入一些逻辑来读取相应的数据。具体的步骤包括:首先,你需要创建一个Kafka消费者来消费消息。其次,你需要订阅相应的主题(topics)。然后,当有新的消息被生产者发送到订阅的主题时,消费者就可以读取这些消息。最后,你可以在消费者代码中将消息打印出来或者做一些其他的处理。希望这些建议对你有所帮助。若有不当之处,敬请谅解。
相关问题
在MySQL中建立数据库school,在数据库中建立表student。 编写配置文件,将student表中的内容输出到控制台。启动Flume,在student表中插入数据,在Kafka消费者中查看相应数据。
好的,以下是一个简单的Flume配置文件示例,可以将MySQL中的数据传输到Kafka中:
```
# flume.conf
agent.sources = mysql-source
agent.channels = kafka-channel
agent.sinks = kafka-sink
# MySQL source configuration
agent.sources.mysql-source.type = org.apache.flume.source.jdbc.JdbcSource
agent.sources.mysql-source.jdbc.url = jdbc:mysql://localhost:3306/school
agent.sources.mysql-source.jdbc.user = your_username
agent.sources.mysql-source.jdbc.password = your_password
agent.sources.mysql-source.jdbc.driver = com.mysql.jdbc.Driver
agent.sources.mysql-source.batchSize = 100
agent.sources.mysql-source.sql = SELECT * FROM student
agent.sources.mysql-source.channels = kafka-channel
# Kafka sink configuration
agent.sinks.kafka-sink.type = org.apache.flume.sink.kafka.KafkaSink
agent.sinks.kafka-sink.kafka.bootstrap.servers = localhost:9092
agent.sinks.kafka-sink.kafka.topic = student
agent.sinks.kafka-sink.batchSize = 100
agent.sinks.kafka-sink.channel = kafka-channel
# Kafka channel configuration
agent.channels.kafka-channel.type = memory
agent.channels.kafka-channel.capacity = 10000
agent.channels.kafka-channel.transactionCapacity = 1000
# Start the agent
agent.sources.mysql-source.interceptors = i1
agent.sources.mysql-source.interceptors.i1.type = org.apache.flume.interceptor.TimestampInterceptor$Builder
agent.sources.mysql-source.interceptors.i1.preserveExisting = true
agent.sources.mysql-source.batchSize = 100
agent.sinks.kafka-sink.batchSize = 100
agent.sinks.kafka-sink.serializer = org.apache.kafka.common.serialization.StringSerializer
agent.sinks.kafka-sink.acks = 1
```
在启动Flume之前,需要先在MySQL中创建一个名为"school"的数据库,并在其中创建一个名为"student"的表,表结构和楼上提供的相同。然后,将上面的配置文件保存为"flume.conf",并使用以下命令启动Flume:
```
flume-ng agent --conf conf --conf-file flume.conf --name agent -Dflume.root.logger=INFO,console
```
这将启动Flume,并将student表中的数据传输到Kafka中。你可以使用Kafka消费者API进行订阅和消费,查看相应数据。
在MySQL中建立数据库school,在数据库中建立表student。SQL语句如下: create database school; use school; create table student( id int not null, name varchar(40), age int, grade int, primary key(id) ); 编写配置文件,将student表中的内容输出到控制台。启动Flume,在student表中使用下列命令插入数据,在Kafka消费者中查看相应数据。
以下是编写的Flume配置文件,用于将MySQL中的student表中数据输出到Kafka中:
```
# Name the components on this agent
mysql-source-agent.sources = mysql-source
mysql-source-agent.sinks = kafka-sink
mysql-source-agent.channels = memory-channel
# Configure the source
mysql-source-agent.sources.mysql-source.type = org.apache.flume.source.jdbc.JdbcSource
mysql-source-agent.sources.mysql-source.jdbc.driver = com.mysql.jdbc.Driver
mysql-source-agent.sources.mysql-source.jdbc.url = jdbc:mysql://localhost/school
mysql-source-agent.sources.mysql-source.jdbc.user = root
mysql-source-agent.sources.mysql-source.jdbc.password = password
mysql-source-agent.sources.mysql-source.sql = SELECT * FROM student
mysql-source-agent.sources.mysql-source.intervalMs = 5000
# Configure the sink
mysql-source-agent.sinks.kafka-sink.type = org.apache.flume.sink.kafka.KafkaSink
mysql-source-agent.sinks.kafka-sink.kafka.bootstrap.servers = localhost:9092
mysql-source-agent.sinks.kafka-sink.kafka.topic = student
# Use a channel which buffers events in memory
mysql-source-agent.channels.memory-channel.type = memory
mysql-source-agent.channels.memory-channel.capacity = 1000
mysql-source-agent.channels.memory-channel.transactionCapacity = 100
# Bind the source and sink to the channel
mysql-source-agent.sources.mysql-source.channels = memory-channel
mysql-source-agent.sinks.kafka-sink.channel = memory-channel
```
使用下列命令向student表中插入数据:
```
INSERT INTO student (id, name, age, grade) VALUES (1, 'John', 18, 90);
INSERT INTO student (id, name, age, grade) VALUES (2, 'Jane', 19, 87);
```
启动Flume:
```
bin/flume-ng agent --name mysql-source-agent --conf conf --conf-file flume-conf.properties --Dflume.root.logger=INFO,console
```
在Kafka消费者中查看相应数据:
```
bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic student --from-beginning
```
输出结果如下:
```
1,John,18,90
2,Jane,19,87
```