Flume-Kafka-Flume对接Kafka以及Kafka数据分类传输

本是古典何须时尚 2022-09-09 06:21 321阅读 0赞

# Flume 对接 Kafka #

Flume日志采集组件；Flume对接kafka主要是为了通过kafka的topic功能，动态的增加或者减少接收的节点，并且Flume要对接多个节点是需要多个channel和sink的会导致内存不够的情况。

那么可以实现的场景就是Flume采集日志文件，通过kafka给多给业务线使用。

1)配置 flume(flume-kafka.conf)

# define
    a1.sources = r1
    a1.sinks = k1
    a1.channels = c1
    
    # source
    a1.sources.r1.type = netcat
    a1.sources.r1.bind = localhost
    a1.sources.r1.port = 44444
    
    # sink
    a1.sinks.k1.type = org.apache.flume.sink.kafka.KafkaSink
    a1.sinks.k1.kafka.bootstrap.servers = hadoop113:9092,hadoop114:9092,hadoop115:9092
    a1.sinks.k1.kafka.topic = first
    a1.sinks.k1.kafka.flumeBatchSize = 20
    a1.sinks.k1.kafka.producer.acks = 1
    a1.sinks.k1.kafka.producer.linger.ms = 1
    
    # channel
    a1.channels.c1.type = memory
    a1.channels.c1.capacity = 1000
    a1.channels.c1.transactionCapacity = 100
    
    # bind
    a1.sources.r1.channels = c1
    a1.sinks.k1.channel = c1

1.  启动消费者

kafka-console-consumer.sh --zookeeper hadoop113:2181 --topic first

1.  进入 flume 根目录下,启动 flume

bin/flume-ng agent -c conf/ -n a1 -f jobs/flume-kafka.conf

4)启动nc发送数据

[bd@hadoop113 ~]$ nc localhost 44444
    hello
    OK
    word
    OK
    
    结果如下
    [bd@hadoop113 ~]$ kafka-console-consumer.sh --zookeeper hadoop113:2181 --topic first
    hello
    word

## Kafka数据分类 ##

依据Kafka Sink的配置

<table> 
 <thead> 
  <tr> 
   <th>Property Name</th> 
   <th>Default</th> 
   <th>Description</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>kafka.topic</td> 
   <td>default-flume-topic</td> 
   <td>The topic in Kafka to which the messages will be published. If this parameter is configured, messages will be published to this topic. If the event header contains a “topic” field, the event will be published to that topic overriding the topic configured here.</td> 
  </tr> 
 </tbody> 
</table>

在消息头中携带了topic字段的话，该消息就会被发送到topic字段对应的topic去。

那么在flume接收到消息之后，可以通过拦截器为topic加上header，即可将其进行分类。

Flume拦截器如下：

public class JudgeTestStringInterceptor implements Interceptor { 
    
        // 声明一个存放事件的List
        private List<Event> allEvents;
    
        public void initialize () { 
    
            // 初始化
            allEvents = new ArrayList<Event>();
        }
    
        /** * 单个事件拦截 * @param event * @return */
        public Event intercept (Event event) { 
    
            // 1、获取事件中的头信息
            Map<String, String> headers = event.getHeaders();
    
            // 2、获取事件中的body信息
            String body = new String(event.getBody());
    
            // 3、根据body中是否有“test”来决定添加怎样的头信息
            // 有的话添加<topic, first>没有则添加<topic, second>
            if (body.contains("test")) { 
                headers.put("topic", "first");
            } else { 
                headers.put("topic", "second");
            }
    
            return event;
            // 如果返回null则认为该事件无用，将会被过滤
        }
    
        /** * 批量事件拦截 * @param list * @return */
        public List<Event> intercept (List<Event> list) { 
    
            // 1、清空集合
            allEvents.clear();
    
            // 2、遍历event
            for (Event event : list) { 
                // 3、给每个事件添加头信息
                allEvents.add(intercept(event));
            }
    
            return allEvents;
        }
    
        public void close () { 
    
        }
    
        // 定义一个Builder对象
        public static class Builder implements Interceptor.Builder { 
    
            public Interceptor build () { 
    
                return new JudgeTestStringInterceptor();
            }
    
            public void configure (Context context) { 
    
            }
        }
    }

配置文件type-kafka.conf如下：

# define
    a1.sources = r1
    a1.sinks = k1
    a1.channels = c1
    
    # source
    a1.sources.r1.type = netcat
    a1.sources.r1.bind = localhost
    a1.sources.r1.port = 44444
    
    # interceptor
    a1.sources.r1.interceptors = i1
    a1.sources.r1.interceptors.i1.type = com.starnet.interceptor.JudgeTestStringInterceptor$Builder
    
    # sink
    a1.sinks.k1.type = org.apache.flume.sink.kafka.KafkaSink
    a1.sinks.k1.kafka.bootstrap.servers = hadoop113:9092,hadoop114:9092,hadoop115:9092
    a1.sinks.k1.kafka.topic = first
    a1.sinks.k1.kafka.flumeBatchSize = 20
    a1.sinks.k1.kafka.producer.acks = 1
    a1.sinks.k1.kafka.producer.linger.ms = 1
    
    # channel
    a1.channels.c1.type = memory
    a1.channels.c1.capacity = 1000
    a1.channels.c1.transactionCapacity = 100
    
    # bind
    a1.sources.r1.channels = c1
    a1.sinks.k1.channel = c1

启动flume，两个消费者以及nc之后结果如下：

[bd@hadoop113 ~]$ nc localhost 44444
    test
    OK
    hello
    OK
    word
    OK
    
    
    [bd@hadoop113 ~]$ kafka-console-consumer.sh --zookeeper hadoop113:2181 --topic first
    test
    
    [bd@hadoop113 ~]$ kafka-console-consumer.sh --zookeeper hadoop113:2181 --topic second
    hello
    word