feat(db): prod sql connect setup more proper to handle errors as well

backend/app.ts

@@ -1,4 +1,5 @@
 import express from "express";
+import { connectProdSql } from "./src/prodSql/sqlConnection.controller.js";
 import { setupRoutes } from "./src/routeHandler.route.js";
 
 const port = Number(process.env.PORT);
@@ -6,6 +7,9 @@ export const baseUrl = "";
 const startApp = async () => {
 	const app = express();
 
+	// start the connection to the prod sql server
+	connectProdSql();
+
 	setupRoutes(baseUrl, app);
 
 	app.listen(port, () => {

backend/src/configs/prodSql.config.ts

@@ -0,0 +1,19 @@
+import type sql from "mssql";
+export const prodSqlConfig: sql.config = {
+	server: `${process.env.PROD_SERVER}`,
+	database: `AlplaPROD_${process.env.PROD_PLANT_TOKEN}_cus`,
+	user: process.env.PROD_USER,
+	password: process.env.PROD_PASSWORD,
+	options: {
+		encrypt: true,
+		trustServerCertificate: true,
+	},
+	requestTimeout: 90000, // how long until we kill the query and fail it
+	pool: {
+		max: 20, // Maximum number of connections in the pool
+		min: 0, // Minimum number of connections in the pool
+		idleTimeoutMillis: 10000, // How long a connection is allowed to be idle before being released
+		reapIntervalMillis: 1000, // how often to check for idle resources to destroy
+		acquireTimeoutMillis: 100000, // How long until a complete timeout happens
+	},
+};

backend/src/prodSql/sql.route.ts

@@ -0,0 +1,5 @@
+import { Router } from "express";
+
+const r = Router();
+
+export default r;

backend/src/prodSql/sqlConnection.controller.ts

@@ -0,0 +1,135 @@
+import sql from "mssql";
+import { prodSqlConfig } from "../configs/prodSql.config.js";
+import { checkHostnamePort } from "../utils/checkHost.utils.js";
+import { returnFunc } from "../utils/returnHelper.utils.js";
+
+export let pool: sql.ConnectionPool;
+export let connected: boolean = false;
+export let reconnecting = false;
+
+export const connectProdSql = async () => {
+	const serverUp = await checkHostnamePort(`${process.env.PROD_SERVER}:1433`);
+
+	if (!serverUp) {
+		// we will try to reconnect
+		connected = false;
+		return returnFunc({
+			success: false,
+			level: "error",
+			module: "system",
+			subModule: "db",
+			message: "Prod server is offline or unreachable.",
+		});
+	}
+
+	// if we are trying to click restart from the api for some reason we want to kick back and say no
+	if (connected) {
+		return returnFunc({
+			success: false,
+			level: "error",
+			module: "system",
+			subModule: "db",
+			message: "The Sql server is already connected.",
+		});
+	}
+
+	// try to connect to the sql server
+	try {
+		pool = await sql.connect(prodSqlConfig);
+		connected = true;
+		console.log(
+			`${prodSqlConfig.server} is connected to ${prodSqlConfig.database}`,
+		);
+	} catch (error) {
+		return returnFunc({
+			success: false,
+			level: "error",
+			module: "system",
+			subModule: "db",
+			message: "Failed to connect to the prod sql server.",
+			data: [error],
+			notify: false,
+		});
+	}
+};
+
+export const closePool = async () => {
+	if (!connected) {
+		return returnFunc({
+			success: false,
+			level: "error",
+			module: "system",
+			subModule: "db",
+			message: "There is no connection to the prod server currently.",
+		});
+	}
+
+	try {
+		await pool.close();
+		console.log("Connection pool closed");
+		connected = false;
+		return {
+			success: true,
+			message: "The sql server connection has been closed",
+		};
+	} catch (error) {
+		connected = false;
+		console.log("There was an error closing the sql connection", error);
+	}
+};
+export const reconnectToSql = async () => {
+	if (reconnecting) return;
+
+	//set reconnecting to true while we try to reconnect
+	reconnecting = true;
+
+	// start the delay out as 2 seconds
+	let delayStart = 2000;
+	let attempt = 0;
+	const maxAttempts = 10;
+
+	while (!connected && attempt < maxAttempts) {
+		attempt++;
+		console.log(
+			`Reconnect attempt ${attempt}/${maxAttempts} in ${delayStart / 1000}s ...`,
+		);
+
+		await new Promise((res) => setTimeout(res, delayStart));
+
+		const serverUp = await checkHostnamePort(`${process.env.PROD_SERVER}:1433`);
+
+		if (!serverUp) {
+			delayStart = Math.min(delayStart * 2, 30000); // exponential backoff until up to 30000
+			return;
+		}
+
+		try {
+			pool = await sql.connect(prodSqlConfig);
+			reconnecting = false;
+			connected = true;
+			console.log(
+				`${prodSqlConfig.server} is connected to ${prodSqlConfig.database}`,
+			);
+		} catch (error) {
+			delayStart = Math.min(delayStart * 2, 30000);
+			return returnFunc({
+				success: false,
+				level: "error",
+				module: "system",
+				subModule: "db",
+				message: "Failed to reconnect to the prod sql server.",
+				data: [error],
+				notify: false,
+			});
+		}
+	}
+
+	if (!connected) {
+		console.log(
+			"Max reconnect attempts reached on the prodSql server. Stopping retries.",
+		);
+
+		reconnecting = false;
+		// exit alert someone here
+	}
+};

package.json

@@ -11,7 +11,7 @@
 		"build": "esbuild backend/app.ts --bundle --platform=node --minify --outfile=dist/index.js --format=esm --packages=external",
 		"build:app": "ncc build backend/app.ts -o dist -m -s",
 		"lint": "tsc",
-		"start": "node dist/index.js",
+		"start": "dotenvx run -f .env -- node dist/index.js",
 		"commit": "cz",
 		"changeset": "changeset",
 		"version": "changeset version",