需要借助的库
github.com/Shopify/sarama // kafka主要的库*
github.com/bsm/sarama-cluster // kafka消费组
生产者
package producer
import (
"fmt"
"github.com/HappyTeemo7569/teemoKit/tlog"
"github.com/Shopify/sarama"
"kafkaDemo/define"
var (
ProducerId = 1
type Producer struct {
Producer sarama.SyncProducer
Topic string //主题
ProducerID int //生产者Id
MessageId int
}
func (p *Producer InitProducer( {
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
// 连接kafka
client, err := sarama.NewSyncProducer([]string{define.SERVER_LIST}, config
if err != nil {
tlog.Error("producer closed, err:", err
return
}
p.Producer = client
p.Topic = define.TOPIC
p.ProducerID = ProducerId
p.MessageId = 1
ProducerId++
}
func (p *Producer SendMessage( {
// 构造一个消息
msg := &sarama.ProducerMessage{}
msg.Topic = p.Topic
txt := fmt.Sprintf("ProducerID:%d this is a test log %d",
p.ProducerID, p.MessageId
msg.Value = sarama.StringEncoder(txt
// 发送消息
pid, offset, err := p.Producer.SendMessage(msg
//_, _, err := client.SendMessage(msg
if err != nil {
fmt.Println("send msg failed, err:", err
return
}
tlog.Info(fmt.Sprintf("ProducerID:%d pid:%v offset:%v msg:%s",
p.ProducerID, pid, offset, txt
p.MessageId++
}
func (p *Producer Close( {
p.Producer.Close(
}
消费者
package consumer
import (
"github.com/HappyTeemo7569/teemoKit/tlog"
"github.com/Shopify/sarama"
"kafkaDemo/define"
type Consumer struct {
Consumer sarama.Consumer
Topic string
ConsumerId int //消费者Id
}
func (c *Consumer InitConsumer( error {
consumer, err := sarama.NewConsumer([]string{define.SERVER_LIST}, nil
if err != nil {
return err
}
c.Consumer = consumer
c.Topic = define.TOPIC
c.ConsumerId = ConsumerId
ConsumerId++
return nil
}
//指定partition
//offset 可以指定，传-1为获取最新offest
func (c *Consumer GetMessage(partitionId int32, offset int64 {
if offset == -1 {
offset = sarama.OffsetNewest
}
pc, err := c.Consumer.ConsumePartition(c.Topic, partitionId, offset
if err != nil {
tlog.Error("failed to start consumer for partition %d,err:%v", partitionId, err
//That topic/partition is already being consumed
return
}
// 异步从每个分区消费信息
go func(sarama.PartitionConsumer {
for msg := range pc.Messages( {
tlog.Info("ConsumerId:%d Partition:%d Offset:%d Key:%v Value:%v", c.ConsumerId, msg.Partition, msg.Offset, msg.Key, string(msg.Value
}
}(pc
}
//遍历所有分区
func (c *Consumer GetMessageToAll(offset int64 {
partitionList, err := c.Consumer.Partitions(c.Topic // 根据topic取到所有的分区
if err != nil {
tlog.Error("fail to get list of partition:err%v", err
return
}
tlog.Info("所有partition:", partitionList
for partition := range partitionList { // 遍历所有的分区
c.GetMessage(int32(partition, offset
}
}
主函数
func main( {
tlog.Info("开始"
go producer.Put(
go consumer.Get(
for {
time.Sleep(time.Hour * 60
}
}
func Put( {
producer := new(Producer
producer.InitProducer(
go func( {
for {
producer.SendMessage(
time.Sleep(1 * time.Second
}
}(
}
func Get( {
offest := int64(0
consumer := new(Consumer
err := consumer.InitConsumer(
if err != nil {
tlog.Error("fail to init consumer, err:%v", err
return
}
consumer.GetMessageToAll(offest
}
具体源码可以查看：
kafka_demo
生产环境中的优化
- 可以存储消费的节点到redis
- 需要顺序的消费的放到一个partition，或者利用哈希算法投递
- 传入一个通道，将业务逻辑和底层逻辑解耦。
package kafka
import (
"crypto/tls"
"crypto/x509"
"fmt"
"github.com/Shopify/sarama"
"io/ioutil"
"log"
"sync"
"vliao.com/stellar/internal/core"
type KafkaConsumer struct {
Node []string
Consumer sarama.Consumer
Topic string
MessageQueue chan []byte
}
func NewKafkaConsumer(topic string KafkaConsumer {
return KafkaConsumer{
Node: core.GetKafkaConn(.Conn,
Topic: core.GetServerMode( + "_" + topic,
}
}
// Consume 获取所有分区
func (c *KafkaConsumer Consume( {
config := sarama.NewConfig(
config.Net.SASL.Enable = true
config.Net.SASL.User = core.GetKafkaConn(.SASLUser
config.Net.SASL.Password = core.GetKafkaConn(.SASLPassword
config.Net.SASL.Handshake = true
certBytes, err := ioutil.ReadFile(GetFullPath("only-4096-ca-cert"
if err != nil {
fmt.Println("kafka client read cert file failed ", err.Error(
return
}
clientCertPool := x509.NewCertPool(
ok := clientCertPool.AppendCertsFromPEM(certBytes
if !ok {
fmt.Println("kafka client failed to parse root certificate"
return
}
config.Net.TLS.Config = &tls.Config{
RootCAs: clientCertPool,
InsecureSkipVerify: true,
}
config.Net.TLS.Enable = true
consumer, err := sarama.NewConsumer(c.Node, config
if err != nil {
log.Fatal("NewConsumer err: ", err
}
defer consumer.Close(
// 先查询该 topic 有多少分区
partitions, err := consumer.Partitions(c.Topic
if err != nil {
log.Fatal("Partitions err: ", err
}
var wg sync.WaitGroup
wg.Add(len(partitions
// 然后每个分区开一个 goroutine 来消费
for _, partitionId := range partitions {
//不开异步会导致一个消费完才会消费另外一个
go c.consumeByPartition(consumer, c.Topic, partitionId, &wg
}
wg.Wait(
}
// 暂时只是业务一对一，也就是一个生产者产生的消息不会触发多个业务的变动
// 但是可以开多个消费者增加处理能力
func getOffsetCacheKey(topic string, partitionId int32 string {
return fmt.Sprintf("kafka_offset_%s_%d", topic, partitionId
}
func setConsumeOffset(topic string, partitionId int32, offset int64 {
core.RedisBy(core.RedisTypeServer.SetInt64(getOffsetCacheKey(topic, partitionId, offset
}
func getConsumeOffset(topic string, partitionId int32 (offset int64 {
key := getOffsetCacheKey(topic, partitionId
if core.RedisBy(core.RedisTypeServer.Exists(key {
return core.RedisBy(core.RedisTypeServer.GetInt64(key + 1
}
//默认从最新开始
setConsumeOffset(topic, partitionId, sarama.OffsetNewest
return sarama.OffsetNewest
}
func (c *KafkaConsumer consumeByPartition(consumer sarama.Consumer, topic string, partitionId int32, wg *sync.WaitGroup {
defer wg.Done(
offset := getConsumeOffset(topic, partitionId
partitionConsumer, err := consumer.ConsumePartition(topic, partitionId, offset
if err != nil {
log.Fatal("ConsumePartition err: ", err
}
defer partitionConsumer.Close(
for message := range partitionConsumer.Messages( {
log.Printf("[Consumer] topic: %s ; partitionid: %d; offset:%d, value: %s\n", topic, message.Partition, message.Offset, string(message.Value
setConsumeOffset(topic, partitionId, message.Offset
c.MessageQueue <- message.Value
}
}
package kafka
import (
"log"
"testing"
"vliao.com/stellar/internal/core"
func Test_Get(t *testing.T {
core.TestMain(
topic := "test_log"
var kafkaConsumer = NewKafkaConsumer(topic
kafkaConsumer.MessageQueue = make(chan []byte, 1000
go kafkaConsumer.Consume(
for {
msg := <-kafkaConsumer.MessageQueue
deal(msg
}
}
func deal(msg []byte {
log.Printf(string(msg
}