Go操作NSQ

NSQ是目前比较流行的一个分布式的消息队列,本文主要介绍了NSQ及Go语言如何操作NSQ。

NSQ

NSQ介绍

NSQ是Go语言编写的一个开源的实时分布式内存消息队列,其性能十分优异。 NSQ的优势有以下优势:

  1. NSQ提倡分布式和分散的拓扑,没有单点故障,支持容错和高可用性,并提供可靠的消息交付保证
  2. NSQ支持横向扩展,没有任何集中式代理。
  3. NSQ易于配置和部署,并且内置了管理界面。

NSQ的应用场景

通常来说,消息队列都适用以下场景。

异步处理

参照下图利用消息队列把业务流程中的非关键流程异步化,从而显著降低业务请求的响应时间。 nsq1.png

应用解耦

通过使用消息队列将不同的业务逻辑解耦,降低系统间的耦合,提高系统的健壮性。后续有其他业务要使用订单数据可直接订阅消息队列,提高系统的灵活性。 nsq2.png

流量削峰

类似秒杀(大秒)等场景下,某一时间可能会产生大量的请求,使用消息队列能够为后端处理请求提供一定的缓冲区,保证后端服务的稳定性。 nsq3.png

安装

官方下载页面根据自己的平台下载并解压即可。

NSQ组件

nsqd

nsqd是一个守护进程,它接收、排队并向客户端发送消息。

启动nsqd,指定-broadcast-address=127.0.0.1来配置广播地址

./nsqd -broadcast-address=127.0.0.1

如果是在搭配nsqlookupd使用的模式下需要还指定nsqlookupd地址:

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

如果是部署了多个nsqlookupd节点的集群,那还可以指定多个-lookupd-tcp-address

nsqdq相关配置项如下:

-auth-http-address value
    <addr>:<port> to query auth server (may be given multiple times)
-broadcast-address string
    address that will be registered with lookupd (defaults to the OS hostname) (default "PROSNAKES.local")
-config string
    path to config file
-data-path string
    path to store disk-backed messages
-deflate
    enable deflate feature negotiation (client compression) (default true)
-e2e-processing-latency-percentile value
    message processing time percentiles (as float (0, 1.0]) to track (can be specified multiple times or comma separated '1.0,0.99,0.95', default none)
-e2e-processing-latency-window-time duration
    calculate end to end latency quantiles for this duration of time (ie: 60s would only show quantile calculations from the past 60 seconds) (default 10m0s)
-http-address string
    <addr>:<port> to listen on for HTTP clients (default "0.0.0.0:4151")
-http-client-connect-timeout duration
    timeout for HTTP connect (default 2s)
-http-client-request-timeout duration
    timeout for HTTP request (default 5s)
-https-address string
    <addr>:<port> to listen on for HTTPS clients (default "0.0.0.0:4152")
-log-prefix string
    log message prefix (default "[nsqd] ")
-lookupd-tcp-address value
    lookupd TCP address (may be given multiple times)
-max-body-size int
    maximum size of a single command body (default 5242880)
-max-bytes-per-file int
    number of bytes per diskqueue file before rolling (default 104857600)
-max-deflate-level int
    max deflate compression level a client can negotiate (> values == > nsqd CPU usage) (default 6)
-max-heartbeat-interval duration
    maximum client configurable duration of time between client heartbeats (default 1m0s)
-max-msg-size int
    maximum size of a single message in bytes (default 1048576)
-max-msg-timeout duration
    maximum duration before a message will timeout (default 15m0s)
-max-output-buffer-size int
    maximum client configurable size (in bytes) for a client output buffer (default 65536)
-max-output-buffer-timeout duration
    maximum client configurable duration of time between flushing to a client (default 1s)
-max-rdy-count int
    maximum RDY count for a client (default 2500)
-max-req-timeout duration
    maximum requeuing timeout for a message (default 1h0m0s)
-mem-queue-size int
    number of messages to keep in memory (per topic/channel) (default 10000)
-msg-timeout string
    duration to wait before auto-requeing a message (default "1m0s")
-node-id int
    unique part for message IDs, (int) in range [0,1024) (default is hash of hostname) (default 616)
-snappy
    enable snappy feature negotiation (client compression) (default true)
-statsd-address string
    UDP <addr>:<port> of a statsd daemon for pushing stats
-statsd-interval string
    duration between pushing to statsd (default "1m0s")
-statsd-mem-stats
    toggle sending memory and GC stats to statsd (default true)
-statsd-prefix string
    prefix used for keys sent to statsd (%s for host replacement) (default "nsq.%s")
-sync-every int
    number of messages per diskqueue fsync (default 2500)
-sync-timeout duration
    duration of time per diskqueue fsync (default 2s)
-tcp-address string
    <addr>:<port> to listen on for TCP clients (default "0.0.0.0:4150")
-tls-cert string
    path to certificate file
-tls-client-auth-policy string
    client certificate auth policy ('require' or 'require-verify')
-tls-key string
    path to key file
-tls-min-version value
    minimum SSL/TLS version acceptable ('ssl3.0', 'tls1.0', 'tls1.1', or 'tls1.2') (default 769)
-tls-required
    require TLS for client connections (true, false, tcp-https)
-tls-root-ca-file string
    path to certificate authority file
-verbose
    enable verbose logging
-version
    print version string
-worker-id
    do NOT use this, use --node-id

nsqlookupd

nsqlookupd是维护所有nsqd状态、提供服务发现的守护进程。它能为消费者查找特定topic下的nsqd提供了运行时的自动发现服务。 它不维持持久状态,也不需要与任何其他nsqlookupd实例协调以满足查询。因此根据你系统的冗余要求尽可能多地部署nsqlookupd节点。它们小豪的资源很少,可以与其他服务共存。我们的建议是为每个数据中心运行至少3个集群。

nsqlookupd相关配置项如下:

-broadcast-address string
    address of this lookupd node, (default to the OS hostname) (default "PROSNAKES.local")
-config string
    path to config file
-http-address string
    <addr>:<port> to listen on for HTTP clients (default "0.0.0.0:4161")
-inactive-producer-timeout duration
    duration of time a producer will remain in the active list since its last ping (default 5m0s)
-log-prefix string
    log message prefix (default "[nsqlookupd] ")
-tcp-address string
    <addr>:<port> to listen on for TCP clients (default "0.0.0.0:4160")
-tombstone-lifetime duration
    duration of time a producer will remain tombstoned if registration remains (default 45s)
-verbose
    enable verbose logging
-version
    print version string

nsqadmin

一个实时监控集群状态、执行各种管理任务的Web管理平台。 启动nsqadmin,指定nsqlookupd地址:

./nsqadmin -lookupd-http-address=127.0.0.1:4161

我们可以使用浏览器打开http://127.0.0.1:4171/访问如下管理界面。 nsqadmin0.png

nsqadmin相关的配置项如下:

-allow-config-from-cidr string
    A CIDR from which to allow HTTP requests to the /config endpoint (default "127.0.0.1/8")
-config string
    path to config file
-graphite-url string
    graphite HTTP address
-http-address string
    <addr>:<port> to listen on for HTTP clients (default "0.0.0.0:4171")
-http-client-connect-timeout duration
    timeout for HTTP connect (default 2s)
-http-client-request-timeout duration
    timeout for HTTP request (default 5s)
-http-client-tls-cert string
    path to certificate file for the HTTP client
-http-client-tls-insecure-skip-verify
    configure the HTTP client to skip verification of TLS certificates
-http-client-tls-key string
    path to key file for the HTTP client
-http-client-tls-root-ca-file string
    path to CA file for the HTTP client
-log-prefix string
    log message prefix (default "[nsqadmin] ")
-lookupd-http-address value
    lookupd HTTP address (may be given multiple times)
-notification-http-endpoint string
    HTTP endpoint (fully qualified) to which POST notifications of admin actions will be sent
-nsqd-http-address value
    nsqd HTTP address (may be given multiple times)
-proxy-graphite
    proxy HTTP requests to graphite
-statsd-counter-format string
    The counter stats key formatting applied by the implementation of statsd. If no formatting is desired, set this to an empty string. (default "stats.counters.%s.count")
-statsd-gauge-format string
    The gauge stats key formatting applied by the implementation of statsd. If no formatting is desired, set this to an empty string. (default "stats.gauges.%s")
-statsd-interval duration
    time interval nsqd is configured to push to statsd (must match nsqd) (default 1m0s)
-statsd-prefix string
    prefix used for keys sent to statsd (%s for host replacement, must match nsqd) (default "nsq.%s")
-version
    print version string

NSQ架构

NSQ工作模式

nsq4.png

Topic和Channel

每个nsqd实例旨在一次处理多个数据流。这些数据流称为“topics”,一个topic具有1个或多个“channels”。每个channel都会收到topic所有消息的副本,实际上下游的服务是通过对应的channel来消费topic消息。

topicchannel不是预先配置的。topic在首次使用时创建,方法是将其发布到指定topic,或者订阅指定topic上的channelchannel是通过订阅指定的channel在第一次使用时创建的。

topicchannel都相互独立地缓冲数据,防止缓慢的消费者导致其他chennel的积压(同样适用于topic级别)。

channel可以并且通常会连接多个客户端。假设所有连接的客户端都处于准备接收消息的状态,则每条消息将被传递到随机客户端。例如:

nsq5.gif 总而言之,消息是从topic -> channel(每个channel接收该topic的所有消息的副本)多播的,但是从channel -> consumers均匀分布(每个消费者接收该channel的一部分消息)。

NSQ接收和发送消息流程

nsq6.png

NSQ特性

  • 消息默认不持久化,可以配置成持久化模式。nsq采用的方式时内存+硬盘的模式,当内存到达一定程度时就会将数据持久化到硬盘。
    • 如果将--mem-queue-size设置为0,所有的消息将会存储到磁盘。
    • 服务器重启时也会将当时在内存中的消息持久化。
  • 每条消息至少传递一次。
  • 消息不保证有序。

Go操作NSQ

官方提供了Go语言版的客户端:go-nsq,更多客户端支持请查看CLIENT LIBRARIES

安装

go get -u github.com/nsqio/go-nsq

生产者

一个简单的生产者示例代码如下:

// nsq_producer/main.go
package main

import (
    "bufio"
    "fmt"
    "os"
    "strings"

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

// NSQ Producer Demo

var producer *nsq.Producer

// 初始化生产者
func initProducer(str string) (err error) {
    config := nsq.NewConfig()
    producer, err = nsq.NewProducer(str, config)
    if err != nil {
        fmt.Printf("create producer failed, err:%v\n", err)
        return err
    }
    return nil
}

func main() {
    nsqAddress := "127.0.0.1:4150"
    err := initProducer(nsqAddress)
    if err != nil {
        fmt.Printf("init producer failed, err:%v\n", err)
        return
    }

    reader := bufio.NewReader(os.Stdin) // 从标准输入读取
    for {
        data, err := reader.ReadString('\n')
        if err != nil {
            fmt.Printf("read string from stdin failed, err:%v\n", err)
            continue
        }
        data = strings.TrimSpace(data)
        if strings.ToUpper(data) == "Q" { // 输入Q退出
            break
        }
        // 向 'topic_demo' publish 数据
        err = producer.Publish("topic_demo", []byte(data))
        if err != nil {
            fmt.Printf("publish msg to nsq failed, err:%v\n", err)
            continue
        }
    }
}

将上面的代码编译执行,然后在终端输入两条数据123456

$ ./nsq_producer 
123
2018/10/22 18:41:20 INF    1 (127.0.0.1:4150) connecting to nsqd
456

使用浏览器打开http://127.0.0.1:4171/可以查看到类似下面的页面: 在下面这个页面能看到当前的topic信息: nsqadmin1.png

点击页面上的topic_demo就能进入一个展示更多详细信息的页面,在这个页面上我们可以查看和管理topic,同时能够看到目前在LWZMBP:4151 (127.0.01:4151)这个nsqd上有2条message。又因为没有消费者接入所以暂时没有创建channelnsqadmin2.png

/nodes这个页面我们能够很方便的查看当前接入lookupdnsqd节点。 nsqadmin3.png

这个/counter页面显示了处理的消息数量,因为我们没有接入消费者,所以处理的消息数量为0。 nsqadmin4.png

/lookup界面支持创建topicchannelnsqadmin5.png

消费者

一个简单的消费者示例代码如下:

// nsq_consumer/main.go
package main

import (
    "fmt"
    "os"
    "os/signal"
    "syscall"
    "time"

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

// NSQ Consumer Demo

// MyHandler 是一个消费者类型
type MyHandler struct {
    Title string
}

// HandleMessage 是需要实现的处理消息的方法
func (m *MyHandler) HandleMessage(msg *nsq.Message) (err error) {
    fmt.Printf("%s recv from %v, msg:%v\n", m.Title, msg.NSQDAddress, string(msg.Body))
    return
}

// 初始化消费者
func initConsumer(topic string, channel string, address string) (err error) {
    config := nsq.NewConfig()
    config.LookupdPollInterval = 15 * time.Second
    c, err := nsq.NewConsumer(topic, channel, config)
    if err != nil {
        fmt.Printf("create consumer failed, err:%v\n", err)
        return
    }
    consumer := &MyHandler{
        Title: "沙河1号",
    }
    c.AddHandler(consumer)

    // if err := c.ConnectToNSQD(address); err != nil { // 直接连NSQD
    if err := c.ConnectToNSQLookupd(address); err != nil { // 通过lookupd查询
        return err
    }
    return nil

}

func main() {
    err := initConsumer("topic_demo", "first", "127.0.0.1:4161")
    if err != nil {
        fmt.Printf("init consumer failed, err:%v\n", err)
        return
    }
    c := make(chan os.Signal)        // 定义一个信号的通道
    signal.Notify(c, syscall.SIGINT) // 转发键盘中断信号到c
    <-c                              // 阻塞
}

将上面的代码保存之后编译执行,就能够获取之前我们publish的两条消息了:

$ ./nsq_consumer 
2018/10/22 18:49:06 INF    1 [topic_demo/first] querying nsqlookupd http://127.0.0.1:4161/lookup?topic=topic_demo
2018/10/22 18:49:06 INF    1 [topic_demo/first] (127.0.0.1:4150) connecting to nsqd
沙河1号 recv from 127.0.0.1:4150, msg:123
沙河1号 recv from 127.0.0.1:4150, msg:456

同时在nsqadmin的/counter页面查看到处理的数据数量为2。 nsqadmin6.png

关于go-nsq的更多内容请阅读go-nsq的官方文档

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转载自www.cnblogs.com/nickchen121/p/11517436.html