時間経つと接続切れてエラーがでる

Question

前提

node.js,heroku,mysqlの組み合わせでWEBアプリケーションを開発したのですが、テーブルプラスを閉じるとエラーが起きてしまいます。

実現したいこと

テーブルプラスを閉じてもエラーが起きないようにしたい。

発生している問題・エラーメッセージ

2022-08-08T12:23:07.942613+00:00 app[web.1]: TypeError: Cannot read properties of undefined (reading 'use')
2022-08-08T12:23:07.942613+00:00 app[web.1]: at Object.<anonymous> (/app/app.js:1:5)
2022-08-08T12:23:07.942614+00:00 app[web.1]: at Module._compile (node:internal/modules/cjs/loader:1105:14)
2022-08-08T12:23:07.942614+00:00 app[web.1]: at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
2022-08-08T12:23:07.942614+00:00 app[web.1]: at Module.load (node:internal/modules/cjs/loader:981:32)
2022-08-08T12:23:07.942614+00:00 app[web.1]: at Function.Module._load (node:internal/modules/cjs/loader:822:12)
2022-08-08T12:23:07.942615+00:00 app[web.1]: at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:77:12)
2022-08-08T12:23:07.942615+00:00 app[web.1]: at node:internal/main/run_main_module:17:47
2022-08-08T12:23:08.184088+00:00 heroku[web.1]: Process exited with status 1
2022-08-08T12:23:08.258647+00:00 heroku[web.1]: State changed from starting to crashed
2022-08-08T12:23:11.914771+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=kaimemo1993.herokuapp.com request_id=d03fa3ff-74cd-4a03-9374-03fa3dca7d3c fwd="133.32.129.34" dyno= connect= service= status=503 bytes= protocol=https
2022-08-08T12:24:38.601844+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=kaimemo1993.herokuapp.com request_id=3a336037-9c84-412d-adb9-d32cc03d9c22 fwd="133.32.129.34" dyno= connect= service= status=503 bytes= protocol=https
2022-08-08T12:31:25.000000+00:00 app[api]: Build started by user [e-mail]
2022-08-08T12:31:40.000000+00:00 app[api]: Build succeeded
2022-08-08T12:31:40.451203+00:00 app[api]: Release v39 created by user [e-mail]
2022-08-08T12:31:40.451203+00:00 app[api]: Deploy e3f458b8 by user [e-mail]
2022-08-08T12:31:40.877111+00:00 heroku[web.1]: State changed from crashed to starting
2022-08-08T12:31:42.599609+00:00 heroku[web.1]: Starting process with command `npm start`
2022-08-08T12:31:43.786348+00:00 app[web.1]: 
2022-08-08T12:31:43.786367+00:00 app[web.1]: > list-app@1.0.0 start
2022-08-08T12:31:43.786368+00:00 app[web.1]: > node app.js
2022-08-08T12:31:43.786368+00:00 app[web.1]: 
2022-08-08T12:31:43.966409+00:00 app[web.1]: node:internal/modules/cjs/loader:936
2022-08-08T12:31:43.966410+00:00 app[web.1]: throw err;
2022-08-08T12:31:43.966410+00:00 app[web.1]: ^
2022-08-08T12:31:43.966411+00:00 app[web.1]: 
2022-08-08T12:31:43.966411+00:00 app[web.1]: Error: Cannot find module 'mysql2'
2022-08-08T12:31:43.966411+00:00 app[web.1]: Require stack:
2022-08-08T12:31:43.966412+00:00 app[web.1]: - /app/app.js
2022-08-08T12:31:43.966412+00:00 app[web.1]: at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
2022-08-08T12:31:43.966413+00:00 app[web.1]: at Function.Module._load (node:internal/modules/cjs/loader:778:27)
2022-08-08T12:31:43.966413+00:00 app[web.1]: at Module.require (node:internal/modules/cjs/loader:1005:19)
2022-08-08T12:31:43.966414+00:00 app[web.1]: at require (node:internal/modules/cjs/helpers:102:18)
2022-08-08T12:31:43.966414+00:00 app[web.1]: at Object.<anonymous> (/app/app.js:2:13)
2022-08-08T12:31:43.966415+00:00 app[web.1]: at Module._compile (node:internal/modules/cjs/loader:1105:14)
2022-08-08T12:31:43.966415+00:00 app[web.1]: at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
2022-08-08T12:31:43.966415+00:00 app[web.1]: at Module.load (node:internal/modules/cjs/loader:981:32)
2022-08-08T12:31:43.966416+00:00 app[web.1]: at Function.Module._load (node:internal/modules/cjs/loader:822:12)
2022-08-08T12:31:43.966416+00:00 app[web.1]: at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:77:12) {
2022-08-08T12:31:43.966416+00:00 app[web.1]: code: 'MODULE_NOT_FOUND',
2022-08-08T12:31:43.966417+00:00 app[web.1]: requireStack: [ '/app/app.js' ]
2022-08-08T12:31:43.966417+00:00 app[web.1]: }
2022-08-08T12:31:44.091013+00:00 heroku[web.1]: Process exited with status 1
2022-08-08T12:31:44.282702+00:00 heroku[web.1]: State changed from starting to crashed
2022-08-08T12:31:44.287760+00:00 heroku[web.1]: State changed from crashed to starting
2022-08-08T12:31:46.171264+00:00 heroku[web.1]: Starting process with command `npm start`
2022-08-08T12:31:48.448104+00:00 app[web.1]: 
2022-08-08T12:31:48.448122+00:00 app[web.1]: > list-app@1.0.0 start
2022-08-08T12:31:48.448123+00:00 app[web.1]: > node app.js
2022-08-08T12:31:48.448123+00:00 app[web.1]: 
2022-08-08T12:31:48.702139+00:00 app[web.1]: node:internal/modules/cjs/loader:936
2022-08-08T12:31:48.708444+00:00 app[web.1]: throw err;
2022-08-08T12:31:48.708445+00:00 app[web.1]: ^
2022-08-08T12:31:48.708445+00:00 app[web.1]: 

該当のソースコード

var express = require('express');
var mysql = require('mysql2');
var app = express();


app.use(express.static('public'));
app.use(express.urlencoded({extended: false}));

var db_config = {
    host: '',
  user: '',
  password: '',
  database: ''
};

app.get('/', (req, res) => {
  res.render('top.ejs');
});

app.get('/index', (req, res) => {
  connection.query(
    'SELECT * FROM items',
    (error, results) => {
      res.render('index.ejs', {items: results});
    }
  );
});

app.get('/new', (req, res) => {
  res.render('new.ejs');
});

app.post('/create', (req, res) => {
  connection.query(
    'INSERT INTO items (name) VALUES (?)',
    [req.body.itemName],
    (error, results) => {
      res.redirect('/index');
    }
  );
});

app.post('/delete/:id', (req, res) => {
    connection.query(
        'DELETE FROM items WHERE id = ?',
    [req.params.id],
    (error,results) => {
      res.redirect('/index');
    }
        );
    });

    app.get('/edit/:id', (req, res) => {
        connection.query(
            'SELECT * FROM items WHERE id = ?',
            [req.params.id],
            (error, results) => {
        res.render('edit.ejs',{item:results[0]});
        }
          );
        });

        app.post('/update/:id', (req, res) => {
            connection.query(
                'UPDATE items SET name = ? WHERE id = ?',
                [req.body.itemName , req.params.id],
                (error, results) => {
                res.redirect('/index');
                }
              );
            });





            app.set('port', (process.env.PORT || 5000));

            var connection;
            
            function handleDisconnect() {
                console.log('INFO.CONNECTION_DB: ');
                connection = mysql.createConnection(db_config);
                
                connection.connect(function(err) {
                    if (err) {
                        console.log('ERROR.CONNECTION_DB: ', err);
                        setTimeout(handleDisconnect, 1000);
                    }
                });
                
                connection.on('error', function(err) {
                    console.log('ERROR.DB: ', err);
                    if (err.code === 'PROTOCOL_CONNECTION_LOST') {
                        console.log('ERROR.CONNECTION_LOST: ', err);
                        handleDisconnect();
                    } else {
                        throw err;
                    }
                });
            }
            
            handleDisconnect();
            
            app.get('/', function(request, response) {
                connection.query('SELECT * FROM items WHERE id = ?', function(err, rows, fields){
                    if(err){
                        console.log('ERROR.SELECT_DB: ', err);
                        throw err;
                    }
                    response.writeHead(200,{'Content-Type': 'text/plain'});
                    response.write(rows[0].message);
                    response.end();
                });
            });
            
            app.listen(app.get('port'), function() {
                console.log('heroku-mysql app is running on port', app.get('port'));
            });




app.listen(process.env.PORT || 3000);

試したこと

https://ninna2.hatenablog.com/entry/2017/02/22/node-mysql%E3%81%A7%E6%8E%A5%E7%B6%9A%E3%81%8C%E5%88%87%E3%82%8C%E3%82%8B%E7%82%B9%E3%82%92%E6%94%B9%E5%96%84
こちらのサイトのPROTOCOL_CONNECTION_LOSTの方を試してみたのですが、それでもエラーが出てしまいます。
ターミナルにてnpm install mysql2導入済み。

Comments

[m.ts10806]

>【再掲載】

質問は編集できますし、編集したり回答などがあればアクティブとして上がってくるので立て直す必要はないです。
むしろ削除依頼してたとしても未解決のまま同じ質問繰り返す方が印象良くないかと。

[退会済みユーザー]

どうせこの質問に助言しても削除申請するんだろうなって思えてしまって、他人の労力にありがたみを感じない人なんだろうなって印象がついてしまった

[slemntqe]

過去の質問も「解決しました」とコメントしながらも感謝する気持ちは無く、質問も受付中のままになっていますね。あなたの利己的な性格が伺えます。回答する意思が削がれます。