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Comment by geophile | Hacker News Reader

Even in development.

You could, I suppose, but I'm not sure why you would want to. Going back and forth to two debuggers (at least) seems like torture. And with multiple processes, timing and synchronization issues could make interactive debugging a real nightmare. Why? Why would you do this?

Interactive debugging doesn't scale in any dimension.

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I used intellij to debug 3 processes over ssh, it worked seamlessly. The problem with logging is that you have to know where to log. Debuggers are excellent for exploration, where logging implies you already put the code. If you forget some log you need to do the whole build/deploy dance, with a debugger I just restart. There are even time travel debuggers that allow replays.

> The problem with logging is that you have to know where to log.

I start with basic lifecycle logging, at an INFO level: The FooBar is created, the FooBar is destroyed, and major states in between. If a FooBar manages a set of things, then I might also add DEBUG level logging for operations on those things. But mostly, detailed logging comes later, as I investigate problems. You really can't anticipate too much logging, because you don't know what's going to need it.

It's really not that hard, especially if you can run them all from the same IDE. I can see how it starts to get out hand but it's not at n=2.

Early in my software career, I was debugging a compiler problem. Version X worked, version X+1 did not. I debugged by tracing both step by step, in two gdb sessions, looking for when behavior diverged. Pure torture, and that was an extremely simple case -- the processes were not communicating in any way.

All the usual problems, but doubled. Oops, I stepped too far, start over. Oops, the other one stepped too far, start over. Oops, start over, oops, start over.

Never again.

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