操作Kafka
Kafka 是一种高吞吐量的分布式发布订阅消息系统，它可以处理消费者规模的网站中的所有动作流数据，具有高性能、持久化、多副本备份、横向扩展等特点。本文介绍了如何使用 Go 语言发送和接收 kafka 消息。
sarama
Go 语言中连接 kafka 使用第三方库:github.com/Shopify/sar…。
下载及安装
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go get github.com/Shopify/sarama |
注意事项
sarama v1.20 之后的版本加入了zstd压缩算法，需要用到 cgo，在 Windows 平台编译时会提示类似如下错误：
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# github.com/DataDog/zstdexec: "gcc":executable file not found in %PATH% |
所以在 Windows 平台请使用 v1.19 版本的 sarama。
连接 kafka 发送消息
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package mainimport ( "fmt" "github.com/Shopify/sarama")// 基于sarama第三方库开发的kafka clientfunc main() { config := sarama.NewConfig() config.Producer.RequiredAcks = sarama.WaitForAll // 发送完数据需要leader和follow都确认 config.Producer.Partitioner = sarama.NewRandomPartitioner // 新选出一个partition config.Producer.Return.Successes = true // 成功交付的消息将在success channel返回 // 构造一个消息 msg := &sarama.ProducerMessage{} msg.Topic = "web_log" msg.Value = sarama.StringEncoder("this is a test log") // 连接kafka client, err := sarama.NewSyncProducer([]string{"192.168.1.7:9092"}, config) if err != nil { fmt.Println("producer closed, err:", err) return } defer client.Close() // 发送消息 pid, offset, err := client.SendMessage(msg) if err != nil { fmt.Println("send msg failed, err:", err) return } fmt.Printf("pid:%v offset:%v\n", pid, offset)} |
连接 kafka 消费消息
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package mainimport ( "fmt" "github.com/Shopify/sarama")// kafka consumerfunc main() { consumer, err := sarama.NewConsumer([]string{"127.0.0.1:9092"}, nil) if err != nil { fmt.Printf("fail to start consumer, err:%v\n", err) return } partitionList, err := consumer.Partitions("web_log") // 根据topic取到所有的分区 if err != nil { fmt.Printf("fail to get list of partition:err%v\n", err) return } fmt.Println(partitionList) for partition := range partitionList { // 遍历所有的分区 // 针对每个分区创建一个对应的分区消费者 pc, err := consumer.ConsumePartition("web_log", int32(partition), sarama.OffsetNewest) if err != nil { fmt.Printf("failed to start consumer for partition %d,err:%v\n", partition, err) return } defer pc.AsyncClose() // 异步从每个分区消费信息 go func(sarama.PartitionConsumer) { for msg := range pc.Messages() { fmt.Printf("Partition:%d Offset:%d Key:%v Value:%v", msg.Partition, msg.Offset, msg.Key, msg.Value) } }(pc) }} |
操作Etcd
这里使用官方的etcd/clientv3包来连接etcd并进行相关操作。
安装
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go get go.etcd.io/etcd/clientv3 |
put和get操作
put命令用来设置键值对数据，get命令用来根据key获取值。
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package mainimport ( "context" "fmt" "time" "go.etcd.io/etcd/clientv3")func main(){ cli, err := clientv3.New(clientv3.Config{ Endpoints: []string{"122.51.79.172:2379"}, DialTimeout: 5 * time.Second, }) if err != nil { // handle error! fmt.Printf("connect to etcd failed, err:%v\n", err) return } fmt.Println("connect to etcd success") defer cli.Close() // put ctx, cancel := context.WithTimeout(context.Background(), time.Second) _, err = cli.Put(ctx, "coolops", "test") cancel() if err != nil { fmt.Printf("put to etcd failed, err:%v\n", err) return } // get ctx, cancel = context.WithTimeout(context.Background(), time.Second) resp, err := cli.Get(ctx, "coolops") cancel() if err != nil { fmt.Printf("get from etcd failed, err:%v\n", err) return } for _, ev := range resp.Kvs { fmt.Printf("%s:%s\n", ev.Key, ev.Value) }} |
watch操作
watch用来获取未来更改的通知。
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package mainimport ( "context" "fmt" "time" "go.etcd.io/etcd/clientv3")func main(){ cli, err := clientv3.New(clientv3.Config{ Endpoints: []string{"122.51.79.172:2379"}, DialTimeout: 5 * time.Second, }) if err != nil { // handle error! fmt.Printf("connect to etcd failed, err:%v\n", err) return } fmt.Println("connect to etcd success") defer cli.Close() // watch 操作，返回的是一个通道 rch := cli.Watch(context.Background(), "coolops") // <-chan WatchResponse for wresp := range rch { for _, ev := range wresp.Events { fmt.Printf("Type: %s Key:%s Value:%s\n", ev.Type, ev.Kv.Key, ev.Kv.Value) } }} |
安装报错：
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go: finding github.com/coreos/pkg latest# github.com/coreos/etcd/clientv3/balancer/resolver/endpointE:\DEV\Go\pkg\mod\github.com\coreos\etcd@v3.3.19+incompatible\clientv3\balancer\resolver\endpoint\endpoint.go:114:78: undefined: resolver.BuildOptionE:\DEV\Go\pkg\mod\github.com\coreos\etcd@v3.3.19+incompatible\clientv3\balancer\resolver\endpoint\endpoint.go:182:31: undefined: resolver.ResolveNowOption# github.com/coreos/etcd/clientv3/balancer/pickerE:\DEV\Go\pkg\mod\github.com\coreos\etcd@v3.3.19+incompatible\clientv3\balancer\picker\err.go:37:44: undefined: balancer.PickOptionsE:\DEV\Go\pkg\mod\github.com\coreos\etcd@v3.3.19+incompatible\clientv3\balancer\picker\roundrobin_balanced.go:55:54: undefined: balancer.PickOptions |
解决： 将go.mod里的prpc改为1.26.0版本
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google.golang.org/grpc v1.26.0 |
以上就是Go操作Kafka和Etcd方法详解的详细内容，更多关于Go操作Kafka Etcd的资料请关注服务器之家其它相关文章！
原文链接：https://juejin.cn/post/7129376877449314335
