Is there a way to ensure that Express JS retains local variables even after server restarts?

I have set up an Express server in NodeJS v14.15.1 to handle both HTTP GET and POST requests. As part of the server operations, a key is generated and stored as a global variable within my index.js file where the express() app is located. The issue I am facing is that every time the server restarts (using nodemon) after handling an HTTP request, the global key variable gets reset, causing subsequent requests relying on it to fail. It's important to note that I cannot store the key on-disk or on the client-side for security reasons, and this setup is for a university assignment, not a real production environment.

Does anyone have any suggestions on how to maintain the global variable through server restarts?

Your assistance would be greatly appreciated.

node.jsexpress

Answer №1

In the nodejs/Express environment, data does not automatically persist from one restart to the next. To ensure specific data is always available after a restart, it should be saved to disk, typically in a JSON file. This way, when the server starts up again, it can read the previous state from the JSON file and initialize variables accordingly.

It's worth noting that the server restarts automatically (using nodemon) every time it handles an HTTP request.

This continuous restarting should not occur. The server should ideally run for extended periods without needing to restart, even when handling millions of HTTP requests. If the server is crashing and restarting or if nodemon is triggering automatic restarts due to detecting changes, this issue needs to be resolved.

Nodemon is commonly used in a developer mode where it automatically restarts the server upon file changes in a specified directory, aiding faster development cycles during source code edits. However, this functionality should only happen during debugging or development phases. Configuration adjustments may be necessary to avoid unnecessary restarts linked to normal server operations.

The key cannot be stored on-disk.

To retain data post-restart, alternative storage solutions must be explored. As nothing within the Express process persists through a restart, keeping vital data solely within the process will result in loss after each restart. Options include preventing the server from restarting or securing the key in a suitable storage location.

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