当我发送mulitpart表单时，我在Heroku上的部署不断因POST请求而崩溃。我在日志中看不到它是在上载（multer）功能，保存（猫鼬）功能还是sendMail（nodemailer）功能上。 我在日志中唯一看到的是H18错误：内部服务器。
Router.js
const express = require("express");
const mongoose = require("mongoose");
const router = express.Router();
const multer = require("multer");
const path = require("path");
const File = require("../models/Files");
const mail = require("../handlers/mailer");
// Set storage engine
const storage = multer.memoryStorage();
// Init upload
const upload = multer({
storage: storage
}).single("file");
router.get("/", (req, res) => {
res.render("index");
});
router.post("/send", async (req, res, next) => {
await upload(req, res, async err => {
if (err) {
console.log("error by uploading file:", err);
} else {
console.log(`File is uploaded to the memoryStorage: ${req.file.originalname} `);
}
// Create a model to save in the database
const fileUpload = new File({
fromEmail: "<dk@bigbrother.nl>",
fromName: '"Dennis Klarenbeek "',
email: req.body.email,
subject: req.body.subject,
msg: req.body.msg,
filename: req.file.originalname
});
await fileUpload.save((err, file, rows) => {
if (err) {
console.log("error on saving in the db");
} else {
console.log(`database item has been created: ${file.filename}`);
}
});
// Mail the uploaded attachment
await mail.send({
fromEmail: "dennis.klarenbeek@icloud.com",
fromName: '"Dennis Klarenbeek "',
toEmail: req.body.email,
toName: req.body.name,
subject: req.body.subject,
msg: req.body.msg,
template: "attachment",
attachments: [
{
filename: req.file.filename,
contentType: req.file.mimetype,
content: req.file.buffer
}
]
});
});
res.redirect("/");
});
module.exports = router;
日志
2018-07-12T15:29:46.104415+00:00 heroku[router]: at=info method=GET path="/css/style.css" host=stormy-ocean-50061.herokuapp.com request_id=57113d1c-9730-40ca-9f41-0d5111854175 fwd="87.251.40.140" dyno=web.1 connect=1ms service=10ms status=304 bytes=237 protocol=https
2018-07-12T15:29:46.103429+00:00 heroku[router]: at=info method=GET path="/css/normalize.css" host=stormy-ocean-50061.herokuapp.com request_id=44a0f90b-1973-4daf-9f40-1e5e5398b9e4 fwd="87.251.40.140" dyno=web.1 connect=1ms service=7ms status=304 bytes=238 protocol=https
2018-07-12T15:29:46.487118+00:00 app[web.1]: [0mGET /webfonts/fa-light-300.woff2 [36m304 [0m0.353 ms - -[0m
2018-07-12T15:29:46.489183+00:00 heroku[router]: at=info method=GET path="/webfonts/fa-light-300.woff2" host=stormy-ocean-50061.herokuapp.com request_id=885eae11-3e4c-4efa-9b60-b3950d9f256d fwd="87.251.40.140" dyno=web.1 connect=1ms service=2ms status=304 bytes=239 protocol=https
2018-07-12T15:29:56.919861+00:00 app[web.1]: [0mPOST /send [36m302 [0m9.041 ms - 46[0m
2018-07-12T15:29:57.100559+00:00 heroku[router]: sock=backend at=error code=H18 desc="Server Request Interrupted" method=POST path="/send" host=stormy-ocean-50061.herokuapp.com request_id=aaafb074-b538-4983-bef1-fa1abf1f2413 fwd="87.251.40.140" dyno=web.1 connect=1ms service=191ms status=503 bytes=234 protocol=https
有人知道这可能是什么吗？
答案 0 :(得分：2)
在响应完成之前销毁套接字时，抛出heroku H18错误。从heroku文档中指出：
通常，H18表示响应具有多个阶段-对于 例如，流式传输大量响应-而其中之一 阶段抛出了错误。”
我们可以执行一些步骤来重构代码，因此我们将multer用作中间件并改善错误处理，从而了解错误的实际发生位置。
要捕获解决等待时引发的错误，您需要将其包装在try...catch块周围。它的工作原理与Promise.catch完全一样。
const express = require("express");
const mongoose = require("mongoose");
const router = express.Router();
const multer = require("multer");
const path = require("path");
const File = require("../models/Files");
const mail = require("../handlers/mailer");
// Set storage engine
const storage = multer.memoryStorage();
// Init upload
const upload = multer({
storage: storage
}).single("file");
router.get("/", (req, res) => {
res.render("index");
});
router.post("/send", async (req, res, next) => {
// No need to await this middleware
upload(req, res, err => {
// Refactor to using recommended multer error handling
// https://github.com/expressjs/multer#error-handling
if (err instanceof multer.MulterError) {
// A Multer error occurred when uploading.
console.log("multer error when uploading file:", err);
return res.sendStatus(500);
} else if (err) {
// An unknown error occurred when uploading.
console.log("unknown error when uploading file:", err);
return res.sendStatus(500);
}
console.log(`File is uploaded to the memoryStorage: ${req.file.originalname} `);
// Create a model to save in the database
const fileUpload = new File({
fromEmail: "<dk@bigbrother.nl>",
fromName: '"Dennis Klarenbeek "',
email: req.body.email,
subject: req.body.subject,
msg: req.body.msg,
filename: req.file.originalname
});
// Try executing awaits or catch thrown errors
try {
await fileUpload.save((err, file, rows) => {
if (err) {
console.log("error on saving in the db");
} else {
console.log(`database item has been created: ${file.filename}`);
}
});
// Mail the uploaded attachment
await mail.send({
fromEmail: "dennis.klarenbeek@icloud.com",
fromName: '"Dennis Klarenbeek "',
toEmail: req.body.email,
toName: req.body.name,
subject: req.body.subject,
msg: req.body.msg,
template: "attachment",
attachments: [
{
filename: req.file.filename,
contentType: req.file.mimetype,
content: req.file.buffer
}
]
});
// Return res here to signify end of function execution
return res.redirect("/");
} catch (err) {
console.log('Error occured in saving to DB or with mail send ', err);
return res.sendStatus(500);
}
});
});
module.exports = router;
这应该使您看到正在发生的实际错误。您当然也可以将错误发送回响应中，现在我只发送状态500来完成响应。
答案 1 :(得分：0)
在nodejs中捕获所有未捕获的异常，以更好地了解发生问题的地方。
将此行添加到您的nodejs文件中
process.on('uncaughtException', function (err) {
console.error(err.stack); // either logs on console or send to other server via api call.
process.exit(1)
})
答案 2 :(得分：0)
我已经意识到，大多数错误是在尝试上传大文件时发生的，尽管heroku说“上传文件的大小没有限制” ，但您的应用可能存储了大文件对于 Heroku平台上的所有请求，超出Heroku时间限制的文件必须在30秒内返回第一个字节，然后导致后端套接字关闭，该套接字属于应用程序的Web进程，位于后端之前返回了HTTP响应。
但是Heroku给出了更多可能导致该错误的原因，我建议您阅读该错误以进一步澄清H18 - Server Request Interrupted
H18错误类似于H13，两者均表示 套接字在响应完成之前已被破坏。使用H13， 套接字已连接，然后销毁而不发送任何数据。 H18 表示套接字已连接，一些数据作为 应用程序响应，但随后套接字被破坏，没有 完成回复。
通常，H18表示响应具有多个阶段-对于 例如，流式传输大量响应-而其中之一 阶段抛出了错误。
要查找错误，请首先检查日志中是否有堆栈跟踪 H18。如果看不到任何内容，则需要更仔细地查看处理程序 对于失败的特定请求。记录每个步骤 响应（包括x-request-id标头）可以提供帮助。
属于您应用的网络进程的后端套接字已关闭 在后端返回HTTP响应之前。