golang kafka client

針對golang的 kafka client 有很多開源package，例如sarama, confluent等等。在使用sarama 包時，高並發中偶爾遇到crash。於是改用confluent-kafka-go，其簡單易用，並且表現穩定。

本文主要介紹confluent-kafka-go的使用方法。
confluent-kafka-go，是kafka官網推薦的golang package。

confluent-kafka-go is Confluent's Golang client for Apache Kafka and the Confluent Platform.

編譯環境搭建

安裝librdkafka

下載

$ git clone https://github.com/edenhill/librdkafka.git
$ cd librdkafka

配置、編譯、安裝

$ ./configure --prefix /usr
$ make
$ sudo make install

配置PKG_CONFIG_PATH

在文件~/.bashrc 末尾添加

export PKG_CONFIG_PATH=/usr/lib/pkgconfig

下載go client

$ go get -u github.com/confluentinc/confluent-kafka-go/kafka

自動下載到GOPATH目錄下，也可到github上自行下載，然后放到GOPATH中。

Example

// Example function-based Apache Kafka producer
package main

/**
 * Copyright 2016 Confluent Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import (
	"fmt"
	"github.com/confluentinc/confluent-kafka-go/kafka"
	"os"
)

func main() {

	if len(os.Args) != 3 {
		fmt.Fprintf(os.Stderr, "Usage: %s <broker> <topic>\n",
			os.Args[0])
		os.Exit(1)
	}

	broker := os.Args[1]
	topic := os.Args[2]

	p, err := kafka.NewProducer(&kafka.ConfigMap{"bootstrap.servers": broker})

	if err != nil {
		fmt.Printf("Failed to create producer: %s\n", err)
		os.Exit(1)
	}

	fmt.Printf("Created Producer %v\n", p)

	// Optional delivery channel, if not specified the Producer object's
	// .Events channel is used.
	deliveryChan := make(chan kafka.Event)

	value := "Hello Go!"
	err = p.Produce(&kafka.Message{TopicPartition: kafka.TopicPartition{Topic: &topic, Partition: kafka.PartitionAny}, Value: []byte(value)}, deliveryChan)

	e := <-deliveryChan
	m := e.(*kafka.Message)

	if m.TopicPartition.Error != nil {
		fmt.Printf("Delivery failed: %v\n", m.TopicPartition.Error)
	} else {
		fmt.Printf("Delivered message to topic %s [%d] at offset %v\n",
			*m.TopicPartition.Topic, m.TopicPartition.Partition, m.TopicPartition.Offset)
	}

	close(deliveryChan)
}

注意：
如果需要鏈接靜態庫，可刪除/usr/lib/下面關於rdkafka的動態庫文件(.so文件)。然后，go build編譯時加上選項 –tags static
例如：

go build -tags static produer.go

更多example，可參考
https://github.com/confluentinc/confluent-kafka-go/tree/master/examples

參考

https://github.com/confluentinc/confluent-kafka-go