Lambda 函数运行时间 > 3 秒 + 每次预热 5-10 秒

Question

我有一个简单的 node.js 函数，其中包含 2 个 REST API 调用和一个托管在 AWS lambda 中的套接字连接输出。它需要 5-10 秒的预热时间和 >3+ 秒的执行时间。

当代码在本地运行时，它会执行两个请求、套接字连接并在大约 1300 毫秒内完成。为什么 AWS 的执行时间增加了一倍以上？我将超时设置为 120 秒，内存设置为 128mb（默认）。

我很欣赏代码不是很整洁；我正在清理它，但暂时需要一些东西。

当被 webhook 订阅调用时，该项目只需通过 API 从 ServiceM8 获取信息，然后将信息格式化为 ZPL 字符串并将它们转发到 tcp 服务器以通过热敏打印机打印。

我的问题是：

1. 是我的代码瓶颈吗？
2. 能否对其进行优化以更快地运行？
3. 我是否只需要为我的功能使用一个预热插件来允许热启动？

我的功能：

'use strict';
//Require libraries
var request = require("request");
var net = require('net');

exports.handler = (event, context, callback) => {
    if (event.eventName != 'webhook_subscription') { 
        callback(null, {});
    }


    //Global Variables
    var strAssetUUID;
    var strAssetURL;
    var strFormUUID;
    var strTestDate;
    var strRetestDate;
    var appliancePass = true;
    var strAccessToken;
    var strResponseUUID;

    //Printer Access
    const tcpUrl = 'example.com';
    const tcpPort = 12345;
    var client = new net.Socket();

    //UUID of Appliance Test Form.
    const strTestFormUUID = 'UUID_of_form';

//Begin function

    /**
     * Inspect the `eventArgs.entry` argument to get details of the change that caused the webhook
     * to fire.
     */
    strResponseUUID = event.eventArgs.entry[0].uuid;
    strAccessToken = event.auth.accessToken;

    console.log('Response UUID: ' + strResponseUUID);
    console.log('Access Token: ' + strAccessToken);

    //URL Options for FormResponse UUID query
    const urlFormResponse = {  
        url: 'https://api.servicem8.com/api_1.0/formresponse.json?%24filter=uuid%20eq%20' + strResponseUUID,
        headers: {
            // Use the temporary Access Token that was issued for this event
            'Authorization': 'Bearer ' + strAccessToken
        }
    };

//Query form Response UUID to get information required.
request.get(urlFormResponse, function(err, res, body) {
    //Check response code from API query
    if (res.statusCode != 200) {
        // Unable to query form response records
        callback(null, {err: "Unable to query form response records, received HTTP " + res.statusCode + "\n\n" + body});
        return;
        }
    //If we do recieve a 200 status code, begin 
    var arrRecords = JSON.parse(body);

    //Store the UUID of the form used for the form response.
    strFormUUID = arrRecords[0].form_uuid;
    console.log('Form UUID: ' + strFormUUID);

    //Store the UUID of the asset the form response relates to.
    strAssetUUID = arrRecords[0].asset_uuid;
    console.log('Asset UUID: ' + strAssetUUID);

    if (strFormUUID == strTestFormUUID){
            //Get the edited date and parse it into a JSON date object.
            var strEditDate = new Date(arrRecords[0].edit_date);
            //Reassemble JSON date to dd-mm-yyyy.
            strTestDate = strEditDate.getDate() + '/' + (strEditDate.getMonth() + 1) + '/' + strEditDate.getFullYear();
            //Extract the response for retest period.
            var strRetestAnswer = JSON.parse(arrRecords[0].field_data);
            strRetestAnswer = strRetestAnswer[0].Response;
            //Appropriate function based on retest response.
            switch(strRetestAnswer) {
                case '3 Months':
                    //Add x months to current test date object
                    strEditDate.setMonth(strEditDate.getMonth() + 3);
                    strRetestDate = strEditDate.getDate() + '/' + (strEditDate.getMonth() + 1) + '/' + strEditDate.getFullYear();
                    break;
                case '6 Months':
                    strEditDate.setMonth(strEditDate.getMonth() + 6);
                    strRetestDate = strEditDate.getDate() + '/' + (strEditDate.getMonth() + 1) + '/' + strEditDate.getFullYear();
                    break;
                case '12 Months':
                    strEditDate.setMonth(strEditDate.getMonth() + 12);
                    strRetestDate = strEditDate.getDate() + '/' + (strEditDate.getMonth() + 1) + '/' + strEditDate.getFullYear();
                    break;
                case '2 Years':
                    strEditDate.setMonth(strEditDate.getMonth() + 24);
                    strRetestDate = strEditDate.getDate() + '/' + (strEditDate.getMonth() + 1) + '/' + strEditDate.getFullYear();
                    break;
                case '5 Years':
                    strEditDate.setMonth(strEditDate.getMonth() + 60);
                    strRetestDate = strEditDate.getDate() + '/' + (strEditDate.getMonth() + 1) + '/' + strEditDate.getFullYear();
                    break;
                default:
                    strRetestDate = "FAIL";
                    appliancePass = false;
            }

            console.log('Appliance Pass: ' + appliancePass);
            console.log('Test Date: ' + strTestDate);
            console.log('Retest Period: ' + strRetestAnswer);
            console.log('Retest Date: ' + strRetestDate);

            //URL Options for Asset UUID query
            const urlAssetResponse = {
            url: 'https://api.servicem8.com/api_1.0/asset/' + strAssetUUID + '.json',
            headers: {
                // Use the temporary Access Token that was issued for this event
                'Authorization': 'Bearer ' + strAccessToken
                }
            };

            //Query the api for the asset URL of the provided asset UUID.
            request.get(urlAssetResponse, function(err, res, body) {
                //Check response code from API query
                if (res.statusCode != 200) {
                    // Unable to query asset records
                    callback(null, {err: "Unable to query asset records, received HTTP " + res.statusCode + "\n\n" + body});
                    return;
                }
                //If we do recieve a 200 status code, begin 
                var strAssetResponse = JSON.parse(body);
                //Store the asset URL
                strAssetURL = 'https://sm8.io/' + strAssetResponse.asset_code;
                console.log('Asset URL: ' + strAssetURL);
            //generate tag and send to printer
            var strZPLPass = ('^XA....^XZ\n');
            var strZPLFail = ('^XA....^XZ\n');
                            //Now that we have our ZPL generated from our dates and URLs
                            //Send the correct ZPL to the printer.
                            client.connect(tcpPort, tcpUrl, function() {
                                console.log('Connected');
                                //Send Appropriate ZPL
                                if (appliancePass) {
                                    client.write(strZPLPass);
                                }else {
                                    client.write(strZPLFail);
                                }
                                console.log('Tag Successfully Printed!');
                                //As the tcp server receiving the string does not return any communication
                                //there is no way to know when the data has been succesfully received in full.
                                //So we simply timeout the connection after 750ms which is generally long enough
                                //to ensure complete transmission.
                                setTimeout(function () {
                                    console.log('Timeout, connection closing...');
                                    client.destroy();
                                    }, 750);
                                });
            });
    }
});
};

Answer 1

首先，我建议你停止使用request 模块并切换到本机。如今，一切都可以在没有大量线路的情况下完成。 request 是一个有 48 个依赖的模块；如果你算一算，一个简单的 GET 请求需要数千行。

您应该始终尽量减少依赖项的复杂性。我使用 Lambda 来检查我的站点的运行状况，获取整个请求并检查 完全不同的服务器上的 HTML。 VPS 位于爱尔兰的 AWS 法兰克福。我的 ms/request 介于 100~150 ms 之间。

这是我正在使用的一个简单的承诺请求：

function request(obj, timeout) {
    return new Promise(function(res, rej) {
        if (typeof obj !== "object") {
            rej("Argument must be a valid http request options object")
        }
        obj.timeout = timeout;
        obj.rejectUnauthorized = false;
        let request = http.get(obj, (response) => {
            if (response.statusCode !== 200) {
                rej("Connection error");
            }
            var body = '';
            response.on('data', (chunk) => {
                body += chunk;
            });
            response.on('end', () => {
                res(body);
            });
            response.on('error', (error) => {
                rej(error);
            });
        });

        request.setTimeout(timeout);
        request.on('error', (error) => {
            rej(error);
        })
        request.on('timeout', () => {
            request.abort();
            rej("Timeout!")
        })
    });
}

例子

const reqOpts = {
    hostname: 'www.example.com',
    port: 443,
    path: '/hello',
    method: 'GET',
    headers: {
        handshake: "eXTNxFMxQL4pRrj6JfzQycn3obHL",
        remoteIpAddress: event.sourceIp || "lambda"
    }
}
try {
    httpTestCall = await request(reqOpts, 250);
}
catch (e) {
    console.error(e);
}

现在基于该更改，使用exports.handler = async(event, context, callback) => {} 将您的处理程序切换为异步，并使用控制台测量每个请求的执行时间，使用console.time() 和console.timeEnd() 处理您的请求或任何内容。从那里您可以看到使用 Cloudwatch 日志降低您的代码的原因。这是基于您的代码的另一个示例：

let reqOpts = {
  hostname: 'api.servicem8.com',
  port: 443,
  path: '/api_1.0/formresponse.json?%24filter=uuid%20eq%20' + strResponseUUID,
  method: 'GET',
  headers: {
    // Use the temporary Access Token that was issued for this event
    'Authorization': 'Bearer ' + strAccessToken
}
}

console.time("=========MEASURE_servicem8=========")
let error = null;
await request(reqOpts, 5555).catch((e)=>{
  error = e;
})
console.timerEnd("=========MEASURE_servicem8=========")
if (error){
  callback(null, {err: "Unable to query form response records, received HTTP" + error}); /* or anything similar */ 
}

参考
https://docs.aws.amazon.com/lambda/latest/dg/best-practices.html
https://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-handler.html

Answer 2

aws lambda 本质上并不快（在撰写此答案时）。启动时间无法保证，而且已知会很高。

如果您需要性能 - 您将无法通过这种方式获得它。