【消息队列技术】nsq

关于nsq的启动：
1. in one shell, start nsqlookupd:
$ nsqlookupd

1. in another shell, start nsqd:
   $ nsqd –lookupd-tcp-address=127.0.0.1:4160

2. in another shell, start nsqadmin:
   $ nsqadmin –lookupd-http-address=127.0.0.1:4161

3. publish an initial message (creates the topic in the cluster, too):
   $ curl -d ‘hello world 1’ ‘http://127.0.0.1:4151/put?topic=test’

4. finally, in another shell, start nsq_to_file:
   $ nsq_to_file –topic=test –output-dir=/tmp –lookupd-http-address=127.0.0.1:4161

5. publish more messages to nsqd:
   $ curl -d ‘hello world 2’ ‘http://127.0.0.1:4151/put?topic=test’
   $ curl -d ‘hello world 3’ ‘http://127.0.0.1:4151/put?topic=test’

6. to verify things worked as expected, in a web browser open http://127.0.0.1:4171/ to view thensqadmin UI and see statistics. Also, check the contents of the log files (test.*.log) written to /tmp.

其中nsqd的http端口为4151,tcp端口为4150，producer和consumer连接的是4150，nsqd负责接收producer产生的消息，并且让consumer从nsqd这里消费消息，nsqlookupd是一个负责管理拓扑信息的守护进程，nsqadmin是一个网页管理页面。

下面用GO实现producer:

package mainimport(    "os"    "github.com/nsqio/go-nsq")func main(){    topic := os.Args[1]  //指定话题    message := os.Args[2]   //指定消息    p, err := nsq.NewProducer("127.0.0.1:4150", nsq.NewConfig())  //第一个参数是nsqd的tcp端口，第二个参数是配置类Config，nsq.NewConfig()产生一个默认的Config    if err != nil{        panic(err)    }    //发布消息时指定topic，消息要转换为字节数组    if err :=p.Publish(topic, []byte(message));err != nil{        panic(err)    }}

下面实现consumer:

package mainimport(    "os"    "fmt"    "github.com/nsqio/go-nsq")//定义一个结构体，实现HandleMessage方法，用于实现Handler接口/*type Handler interface {    HandleMessage(message *Message) error}*/type ConsumerT struct{}func (*ConsumerT)HandleMessage(msg *nsq.Message)error{    fmt.Println(string(msg.Body))    return nil}func main(){    topic := os.Args[1]  //指定话题    channel := os.Args[2]  //指定通道，同一话题的不同通道会将消息进行分发；同一话题同一通道会将消息按序均分到消费者。    var consumer ConsumerT    c, err := nsq.NewConsumer(topic,channel,nsq.NewConfig())        if err != nil{        panic(err)    }    //添加一个Handler    c.AddHandler(&consumer)    //连接到nsqd的tcp端口    if err := c.ConnectToNSQD("127.0.0.1:4150");err != nil{        panic(err)    }    <-make(chan bool)}