nodejs https请求需要过多内存

我正在尝试加载此url的json https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/AmazonEC2/current/index.json . 这个文件有超过600MB的下载空间。

我在lambda函数中使用此代码:

lambda函数的设置超时为10分钟,内存为3008MB。但这个函数要用的不止这些。

let res = await doRequest2('https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/AmazonEC2/current/index.json');

function doRequest2(url) {
  console.log("doRequest");
 return new Promise(function (resolve, reject) {
 const https = require("https");
 const url = "https://pricing.us-east-   1.amazonaws.com/offers/v1.0/aws/AmazonEC2/current/index.json";
 https.get(url, res => {
 res.setEncoding("utf8");
 let body = "";
 res.on("data", data => {
  body += data;
  });
  res.on("end", () => {
   body = JSON.parse(body);
 resolve(body);
 console.log(body);
   });
    res.on("error", () => {
 console.log("Error");
 reject("error");
     });
 });

});
}

JSON下载需要多少内存?