Hacker News Reader

Comment by blenderob | Hacker News Reader

Not quite sure what the big challenge is here. If the work is shifting to the server, you debug on the server! Read the logs. Attach a debugger. Instrument the code if you must! All that usual stuff. This is how web-development has been since the days of CGI. What am I missing?

View on HN

> Read the logs.

I've noted a tendency to not log stuff in some js-first devs i know ... they all say 'i'll reproduce it locally'...

how else would one reproduce a bug? in production?

or is it best practice to patch with logs only without reproduction

There are often additional hints to go by, e.g., the executed network requests, the user path taken or "breadcrumbs", i.e., custom events captured.

Of course that requires a certain operational maturity.

In my head that feels like triaging but idk people really be patching bugs without reproducing? That sounds crazy to me idk why

I've never worked at a place that had local dev used to think computers hated me but wondering if this is better dev practice in general

Who said anything about not reproducing?

It just takes a lot less time to reproduce if you have some logging in production... and some people seem to believe that's not needed.

And if you have logs, you may not need to reproduce it because said logs give you all the info you need.

Disclaimer: circumstances may vary. A bug is a bug is a bug and you may solve it by reading one log line, or you may spend a week with a debugger in your development environment and it will still crash in production when you deploy the fix.

Happy now?

> how else would one reproduce a bug? in production?

I don't think they meant "either" "or". I think they meant that you should not solely rely on reproducing issues locally. If you have good logging, many times, the logs would make it apparent where the issue is. When that fails, then you resort to reproducing the issue locally.

But if an app developer never adds any logs, they would be forced to reproducing the issue locally every single time which is counter productive.

So it isn't either logs or reproduce locally. It is add logs and read logs. But also reproduce locally when you really have to.

Ok genuine question, since I feel like I’m using logs wrong:

How much stuff do you log in the server? I’ve only ever seen devs log basic high-level stuff. But to actually debug something, you need way more information.

I’ve tried sticking debug-level logs that log all sorts of business logic. Pretty much recreating what you would do with console.log when trying to isolate an issue locally.

But then you have your code permanently littered with debug log lines! It makes things… ugly!!

If you NEED detailed logging, do you just deal with the uglified code? Or is there a better solution? Decorators that logs parameters and such automatically??

What's missing are the summaries that web developers are commonly used to. For example, the network tab in the developer tools. It is arguably very handy for development – and often more actionable than having to step through individual requests.

But you are of course also right that you can just attach a debugger. That's also called out in the article.

And these days, you use the same browser debug tools to attach to nodejs.

For local development, yes. But I see that almost never done in production settings, especially with containerized workloads. Is there a neat way to do it in Kubernetes?

Well, I suggest never enabling the debugger in production.

But if you meant a local or dev server where you start node with --inspect then the port to forward is 9229 by default.

Yes, but it's missing the network tab, see https://github.com/nodejs/diagnostics/issues/75

Reply on news.ycombinator.com