golang基础-WaitGroup、kafka消费者

kafka消费者

以下博客是通过生产者创建、发送消息至kafka 
博客链接

现在我们站在消费者的角度，来进行收取消息

package main import ( "fmt" "strings" "sync" "github.com/Shopify/sarama" ) var ( wg sync.WaitGroup ) func main() { //创建消费者 consumer, err := sarama.NewConsumer(strings.Split("192.168.11.48:9092", ","), nil) if err != nil { fmt.Println("Failed to start consumer: %s", err) return } //设置分区 partitionList, err := consumer.Partitions("nginx_log") if err != nil { fmt.Println("Failed to get the list of partitions: ", err) return } fmt.Println(partitionList) //循环分区 for partition := range partitionList { pc, err := consumer.ConsumePartition("nginx_log", int32(partition), sarama.OffsetNewest) if err != nil { fmt.Printf("Failed to start consumer for partition %d: %s\n", partition, err) return } defer pc.AsyncClose() go func(pc sarama.PartitionConsumer) { wg.Add(1) for msg := range pc.Messages() { fmt.Printf("Partition:%d, Offset:%d, Key:%s, Value:%s", msg.Partition, msg.Offset, string(msg.Key), string(msg.Value)) fmt.Println() } wg.Done() }(pc) } //time.Sleep(time.Hour) wg.Wait() consumer.Close() }

接下来我们测试上面的消费者示例代码，在进行测试前我们需要如下的准备工作 
1、启动zookeeper 
2、启动kafka 
3、创立生产者topic

.\bin\windows\kafka-topics.bat --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic linlin  

4、执行生产者发送消息至kafka代码 
5、执行消费者代码程序

第4步的代码如下：

package main

import (
    "fmt" "github.com/Shopify/sarama" ) func main() { config := sarama.NewConfig() config.Producer.RequiredAcks = sarama.WaitForAll config.Producer.Partitioner = sarama.NewRandomPartitioner config.Producer.Return.Successes = true msg := &sarama.ProducerMessage{} msg.Topic = "nginx_log" msg.Value = sarama.StringEncoder("this is a good test, my message is good") client, err := sarama.NewSyncProducer([]string{"192.168.11.28:9092"}, config) if err != nil { fmt.Println("producer close, err:", err) return } defer client.Close() pid, offset, err := client.SendMessage(msg) if err != nil { fmt.Println("send message failed,", err) return } fmt.Printf("pid:%v offset:%v\n", pid, offset) }