限制NodeJS中API的并发请求以及Async / Await

时间:2017-12-13 13:21:19

标签: node.js async-await rate-limiting npm-request

我在Nodejs项目中使用Request包以及 Node V.8.x 中引入的 Async / Await 功能来使用第三方API,一切都很好,直到我遇到API提供商的限制;每秒限制10个并发请求的人。

我尝试了许多可用的NPM软件包,例如速率限制器等,但最近发现article与我的问题相关,它向我介绍了qrate软件包。

我尝试使用以下代码处理此问题:可能我需要使用Callback而不是'done'并在我的'fetchAPIDetails'中处理它 - 非常感谢任何帮助。提前谢谢。

const async = require('async')
const request = require('request-promise')
const qrate = require('qrate')
const q = qrate(worker,1,5)

const worker = async (reqBody, options, done) => {
    const options = { method: 'POST', url: apiURL, body: reqBody, timeout: 5000}
    try{
        const response = await request(options)
        if(response.error){errorHandler(response.error); return {}}
        else {
            const body = response.body // Expecting XML
            console.log(body.toString().slice(200,350))
            return body
        }
        return done
    }
    catch(err){return errorHandler(err)} //errorHandler fn
}

const fetchAPIDetails = async () => {
    const IdArr = [a,b,c] // An array of id, which need to pass in reqBody
    try{
        async.eachLimit(IdArr, 1, async id => {
            const reqBody = await queryBuilder(id) // queryBuilder fn
            q.push(reqBody)
        })

    } catch(err){return errorHandler(err)} //errorHandler fn
}

1 个答案:

答案 0 :(得分:1)

Thank you everyone, who would have worked on my issue here. However, from my further research I get to know, the concurrency of API requests can be handled directly using NPM-Request package, following this article.

Here is my code for reference, for anyone who would like achieve the same:

const request = require('request-promise')
const Parallel = require('async-parallel')

const queryBuilder = async () => { ... } // Builds my Query body (reqBody)
const errorHandler = async (error) => { ... } // Handles Error
const requestHandler = async () => {
    try{
        const response = await request(options)
        console.log(response.toString().slice(200,350))
        return response
    } catch(err){return errorHandler(err)} //errorHandler fn
}

const fetchAPIDetails = async () => {
    const IdArr = [a,b,c] // An array of id, which need to pass in reqBody
    Parallel.concurrency = 1
    try{
        Parallel.each(IdArr, async id => {
            const reqBody = await queryBuilder(id) // queryBuilder fn

        })        
    } catch(err){return errorHandler(err)} //errorHandler fn
 }