nsq

做一下保存,copy过来

转载自：地址

按照[官网(http://nsq.io/overview/quick_start.html)执行的时候

nsqd --lookupd-tcp-address=127.0.0.1:4160

要指定 broadcast-address 是localhost，否则的话会是你默认的主机名，比如（admin），最后导致连接不上

nsqd --lookupd-tcp-address=127.0.0.1:4160 --broadcast-address=127.0.0.1

测试代码

package main

import (
    "fmt"
    "time"

    "github.com/nsqio/go-nsq"
)

// ConsumerHandler 消费者处理者
type ConsumerHandler struct{}

// HandleMessage 处理消息
func (*ConsumerHandler) HandleMessage(msg *nsq.Message) error {
    fmt.Println(string(msg.Body))
    return nil
}

// Producer 生产者
func Producer() {
    producer, err := nsq.NewProducer("127.0.0.1:4150", nsq.NewConfig())
    if err != nil {
        fmt.Println("NewProducer", err)
        panic(err)
    }

    i := 1
    for {
        if err := producer.Publish("test", []byte(fmt.Sprintf("Hello World %d", i))); err != nil {
            fmt.Println("Publish", err)
            panic(err)
        }

        time.Sleep(time.Second * 5)

        i++
    }
}

// ConsumerA 消费者
func ConsumerA() {
    consumer, err := nsq.NewConsumer("test", "test-channel-a", nsq.NewConfig())
    if err != nil {
        fmt.Println("NewConsumer", err)
        panic(err)
    }

    consumer.AddHandler(&ConsumerHandler{})

    if err := consumer.ConnectToNSQLookupd("127.0.0.1:4161"); err != nil {
        fmt.Println("ConnectToNSQLookupd", err)
        panic(err)
    }
}

// ConsumerB 消费者
func ConsumerB() {
    consumer, err := nsq.NewConsumer("test", "test-channel-b", nsq.NewConfig())
    if err != nil {
        fmt.Println("NewConsumer", err)
        panic(err)
    }

    consumer.AddHandler(&ConsumerHandler{})

    if err := consumer.ConnectToNSQLookupd("127.0.0.1:4161"); err != nil {
        fmt.Println("ConnectToNSQLookupd", err)
        panic(err)
    }
}

func main() {
    ConsumerA()
    ConsumerB()
    Producer()
}

命令如下

#cmd1
nsqlookupd

#cmd2
nsqd --lookupd-tcp-address=127.0.0.1:4160 --broadcast-address=127.0.0.1

运行结果

banjakukutekiiMac:test panshiqu$ ./main 
2016/11/24 09:52:49 INF    1 [test/test-channel-a] querying nsqlookupd http://127.0.0.1:4161/lookup?topic=test
2016/11/24 09:52:49 ERR    1 [test/test-channel-a] error querying nsqlookupd (http://127.0.0.1:4161/lookup?topic=test) - got response 404 Not Found "{\"message\":\"TOPIC_NOT_FOUND\"}"
2016/11/24 09:52:49 INF    2 [test/test-channel-b] querying nsqlookupd http://127.0.0.1:4161/lookup?topic=test
2016/11/24 09:52:49 ERR    2 [test/test-channel-b] error querying nsqlookupd (http://127.0.0.1:4161/lookup?topic=test) - got response 404 Not Found "{\"message\":\"TOPIC_NOT_FOUND\"}"
2016/11/24 09:52:49 INF    3 (127.0.0.1:4150) connecting to nsqd
2016/11/24 09:53:57 INF    2 [test/test-channel-b] querying nsqlookupd http://127.0.0.1:4161/lookup?topic=test
2016/11/24 09:53:57 INF    2 [test/test-channel-b] (127.0.0.1:4150) connecting to nsqd
Hello World 1
Hello World 2
Hello World 3
Hello World 4
Hello World 5
Hello World 6
Hello World 7
Hello World 8
Hello World 9
Hello World 10
Hello World 11
Hello World 12
Hello World 13
Hello World 14
Hello World 15
2016/11/24 09:54:01 INF    1 [test/test-channel-a] querying nsqlookupd http://127.0.0.1:4161/lookup?topic=test
2016/11/24 09:54:01 INF    1 [test/test-channel-a] (127.0.0.1:4150) connecting to nsqd
Hello World 16
Hello World 16
Hello World 17
Hello World 17
Hello World 18
Hello World 18

对于输出我作如下理解，因为初次启动 nsq 相关程序，ConsumerA[test/test-channel-a] 查询 nsqlookupd 主题为 test，返回错误，主题不存在。ConsumerB[test/test-channel-b] 也执行上面的动作。这个时候应该不会创建两个 channel，test-channel-a 和 test-channel-b，也不会创建主题。接下来 Producer 成功连接 nsqd，这个时候会创建 test 主题。等待了一会后 ConsumerB 尝试查询主题成功，进而连接 nsqd，成功建立 test-channel-b，消费已被生产出的 15 条消息，因为 test-channel-a 还未被创建，所以目前已有的消息是不会被复制分发的。接着 ConsumerA 尝试查询主题成功，进而连接 nsqd，成功建立 test-channel-a，接下来的消息都是被复制分发的，两个消费者都能收到

两个 channel 都指定为 test-channel-a 将得到如下输出，可以确定的是多个消费者守在同一个 channel 中，同一条消息将只会被一个消费者处理

banjakukutekiiMac:test panshiqu$ go run main.go
2016/11/24 10:23:52 INF    1 [test/test-channel-a] querying nsqlookupd http://127.0.0.1:4161/lookup?topic=test
2016/11/24 10:23:52 INF    1 [test/test-channel-a] (127.0.0.1:4150) connecting to nsqd
2016/11/24 10:23:52 INF    2 [test/test-channel-a] querying nsqlookupd http://127.0.0.1:4161/lookup?topic=test
2016/11/24 10:23:52 INF    2 [test/test-channel-a] (127.0.0.1:4150) connecting to nsqd
2016/11/24 10:23:52 INF    3 (127.0.0.1:4150) connecting to nsqd
Hello World 1
Hello World 2
Hello World 3

参考：地址