Go操作Kafka和Etcd方法詳解

更新時(shí)間：2022年09月02日 08:56:56 作者：?jiǎn)炭?

這篇文章主要為大家介紹了Go操作Kafka和Etcd方法詳解，有需要的朋友可以借鑒參考下，希望能夠有所幫助，祝大家多多進(jìn)步，早日升職加薪

操作Kafka

Kafka 是一種高吞吐量的分布式發(fā)布訂閱消息系統(tǒng)，它可以處理消費(fèi)者規(guī)模的網(wǎng)站中的所有動(dòng)作流數(shù)據(jù)，具有高性能、持久化、多副本備份、橫向擴(kuò)展等特點(diǎn)。本文介紹了如何使用 Go 語(yǔ)言發(fā)送和接收 kafka 消息。

sarama

Go 語(yǔ)言中連接 kafka 使用第三方庫(kù):github.com/Shopify/sar…。

下載及安裝

go get github.com/Shopify/sarama

注意事項(xiàng)

sarama v1.20 之后的版本加入了zstd壓縮算法，需要用到 cgo，在 Windows 平臺(tái)編譯時(shí)會(huì)提示類(lèi)似如下錯(cuò)誤：

# github.com/DataDog/zstd
exec: "gcc":executable file not found in %PATH%

所以在 Windows 平臺(tái)請(qǐng)使用 v1.19 版本的 sarama。

連接 kafka 發(fā)送消息

package main
import (
	"fmt"
	"github.com/Shopify/sarama"
)
// 基于sarama第三方庫(kù)開(kāi)發(fā)的kafka client
func main() {
	config := sarama.NewConfig()
	config.Producer.RequiredAcks = sarama.WaitForAll          // 發(fā)送完數(shù)據(jù)需要leader和follow都確認(rèn)
	config.Producer.Partitioner = sarama.NewRandomPartitioner // 新選出一個(gè)partition
	config.Producer.Return.Successes = true                   // 成功交付的消息將在success channel返回
	// 構(gòu)造一個(gè)消息
	msg := &amp;sarama.ProducerMessage{}
	msg.Topic = "web_log"
	msg.Value = sarama.StringEncoder("this is a test log")
	// 連接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()
	// 發(fā)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)
}

連接 kafka 消費(fèi)消息

package main
import (
	"fmt"
	"github.com/Shopify/sarama"
)
// kafka consumer
func 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") // 根據(jù)topic取到所有的分區(qū)
	if err != nil {
		fmt.Printf("fail to get list of partition:err%v\n", err)
		return
	}
	fmt.Println(partitionList)
	for partition := range partitionList { // 遍歷所有的分區(qū)
		// 針對(duì)每個(gè)分區(qū)創(chuàng)建一個(gè)對(duì)應(yīng)的分區(qū)消費(fèi)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()
		// 異步從每個(gè)分區(qū)消費(fèi)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

這里使用官方的etcd/clientv3包來(lái)連接etcd并進(jìn)行相關(guān)操作。

安裝

go get go.etcd.io/etcd/clientv3

put和get操作

put命令用來(lái)設(shè)置鍵值對(duì)數(shù)據(jù)，get命令用來(lái)根據(jù)key獲取值。

package main
import (
	"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用來(lái)獲取未來(lái)更改的通知。

package main
import (
	"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，返回的是一個(gè)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)
		}
	}
}

安裝報(bào)錯(cuò)：

go: finding github.com/coreos/pkg latest
# github.com/coreos/etcd/clientv3/balancer/resolver/endpoint
E:\DEV\Go\pkg\mod\github.com\coreos\etcd@v3.3.19+incompatible\clientv3\balancer\resolver\endpoint\endpoint.go:114:78: undefined: resolver.BuildOption
E:\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/picker
E:\DEV\Go\pkg\mod\github.com\coreos\etcd@v3.3.19+incompatible\clientv3\balancer\picker\err.go:37:44: undefined: balancer.PickOptions
E:\DEV\Go\pkg\mod\github.com\coreos\etcd@v3.3.19+incompatible\clientv3\balancer\picker\roundrobin_balanced.go:55:54: undefined: balancer.PickOptions

解決：將go.mod里的prpc改為1.26.0版本