Configuring NodeExpress to deploy and prevent Internal Error 500 - mysql

Question

Right now I'm using node on a virtual host, just running npm start and using it's IP to acess the node server.It's a very simple API that just acess an mysql database and returns a json. At first it works alright, however I've noticed that after few hours, running the npm start on pm2, It no longer returns the json for me. It's doesn't crash either, just don't give me back what I requested. Giving me internal error 500.
I would like to know what should I consider in order to properly use Nodejs On produciton mode. And Maybe spot what is causing me the error, since it's a very small application.
var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var cors = require("cors");
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var leisRouter = require('./routes/leis');
var counterRouter = require('./routes/count')
var documentoRouter = require('./routes/documento')
var app = express();
const mysql = require('mysql2');
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
app.use(logger('dev'));
app.use(express.json());
app.use(cors());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', indexRouter);
app.use('/users', usersRouter);
app.use("/leis",leisRouter)
app.use("/count",counterRouter)
app.use("/documento",documentoRouter)
// catch 404 and forward to error handler
app.use(function(req, res, next) {
next(createError(404));
});
// error handler
app.use(function(err, req, res, next) {
// set locals, only providing error in development
res.locals.message = err.message;
res.locals.error = req.app.get('env') === 'development' ? err : {};
// render the error page
res.status(err.status || 500);
res.render('error');
});
I'm just using route : leis and documento
The leis route :
function mapDocumentType(literalType){
switch(literalType){
case 'lei':
return 1
case 'parecer':
return 11;
case 'decreto':
return 2;
case 'circular':
return 3;
case 'portaria':
return 4;
case 'emenda':
return 5;
case 'instrucaoNormativa':
return 6;
case 'comunicado':
return 7;
case 'ordemInterna':
return 8;
case 'orientacaoNormativa':
return 10;
case 'parecerNormativo':
return 12;
case 'portariaConjunta':
return 14;
case 'projetoDeLei':
return 15;
case 'publicacao':
return 16
case 'razoesDeVetoAoProjetoDeLei':
return 17;
case 'resolucaoConjunta':
return 18
case 'leiComplementar':
return 19
}
}
function getQueryFilters(query){
const q = []
Object.entries(query).some(([k,v])=>{
if(v==1){
q.push(mapDocumentType(k))
}
})
if(q.length==0)return ""
return q.toString();
}
router.get("/search/:search_content/:page",function(req,res,next){
var pageM = (req.params.page -1)*10;
let searchValue = req.params.search_content;
//No caso de numero, formata para o padrão ponto entre cada 3 casas decimais. Exemplo 1000 fica como 1.000
let numeric_repr = searchValue.toString().replace(/\B(?=(\d{3})+(?!\d))/g, '.');
if(searchValue == "tudo"){searchValue ="";}
const q = getQueryFilters(req.query);
let datesuffix = "";
console.log(numeric_repr);
if(req.query.dateend !=="" && req.query.datebegin !==""){
datesuffix = `and data_edicao BETWEEN '${req.query.datebegin}' and '${req.query.dateend}'`
}
if(q==""){
connection.query(`SELECT * FROM documento WHERE (descricao_detalhada LIKE '%`+numeric_repr+`%' OR descricao_detalhada LIKE '%`+searchValue+`%' OR
descricao_reduzida LIKE '%`+numeric_repr+`%' OR descricao_reduzida LIKE '%`+searchValue+`%' OR
num_doc ='%`+numeric_repr+`%')`+ datesuffix ,(err,rows,fields)=>{
res.json({content : rows.slice(pageM,pageM+10),row_count:rows.length})
})
}
else{
connection.query(`SELECT * FROM documento WHERE (descricao_detalhada LIKE '%`+numeric_repr+`%' OR descricao_detalhada LIKE '%`+searchValue+`%' OR
descricao_reduzida LIKE '%`+numeric_repr+`%' OR descricao_reduzida LIKE '%`+searchValue+`%' OR
num_doc ='%`+numeric_repr+`%' ) and id_tipo_documento IN (`+q+')'+datesuffix ,(err,rows,fields)=>{
res.json({content : rows.slice(pageM,pageM+10),row_count:rows.length})
})
}
})
module.exports = router;
the final mysql query works alright. However ,after certain time, the when I request this route, it just gives me internal error 500.