CODEWITHSUNDEEP
node.jspromise
Michele
Michele

Reputation: 23

Make multiple get request but with a minute limit of 10 request/minute NodeJS

I'll explain my problem shortly. I am using NodeJS to retrieve response from a url and I have to make multiple request to that URL.

I got only one limit: I can't make more than 10 request for each minute. How can I handle that problem?

I tried to follow that stack overflow response too: Make several requests to an API that can only handle 20 request a minute

but that method its not working because its not awaiting all promise and its giving undefined result

Actually I am using that code but its not awaiting all response, its giving me undefined directly and later all requests are done:

async function rateLimitedRequests(array, chunkSize) {
var delay = 3000 * chunkSize;
var remaining = array.length;
var promises = [];

var addPromises = async function(newPromises) {
    Array.prototype.push.apply(promises, newPromises);
    if (remaining -= newPromises.length == 0) {
        await Promise.all(promises).then((data) => {
            console.log(data);
        });
    }
};

(async function request() {
    addPromises(array.splice(0, chunkSize).map(apiFetch));
    if (array.length) {
        setTimeout(request, delay);
    }
})();

}

Upvotes: 0

Views: 575

Answers (1)

Zain
Zain

Reputation: 98

You can do by implementing Promise.all method.

For example:

const [ response1, response2, response3 ] = await Promise.all([ axios.get(URL_HERE), axios.get(URL_HERE), axios.get(URL_HERE) ];

console.log(response1);

console.log(response3);

console.log(response2);

For Scenario 2 which we discuss below in comment section

function rateLimiter(array = [], chunkSize = 10 ) {

    const delay = 10 * 1000;

    return new Promise((resolve, reject) => {
        let results = [];
        const callback = (iteration = 0) => {
            const process = array.slice(iteration * chunkSize, chunkSize);
            if(!process.length) return resolve(results);

            Promise.all(process).then(responses => {
                results = [ ...results, ...responses ];
                const processLength = array.slice((iteration + 1) * chunkSize, chunkSize).length;
                
                if(!processLength) return resolve(results);
                setTimeout(() => {
                    callback(iteration + 1);
                }, delay)
            })
        }

        callback();

    })
}

let results = await rateLimiter([ axios.get('URL_HERE'), axios.get('URL_HERE') ], 20);

Upvotes: 1

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