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0 pointsaudidude11y ago0 comments

> I don't want to say that one is better than the other but the latter is for most folks far easier to debug and modify than the first.

Generally bad form to make claims on behalf of "most folks" since you are in fact a single person. It's totally a valid argument if you say this on your own behalf.

And yes, bugs happen. But fixing the C code, is in my experience, much easier than tracking them down in `bash -x`. Especially when dealing with race conditions between services/triggers/device initialization.

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5 comments · 3 top-level

nisa11y ago· 2 in thread

Yes. Shell scripts are it's own unique kind of hell. I'm really speaking on my behalf here. I can read shell good enough to follow and debug issues in it. However digging into internals of systemd and its interactions with dbus and other binaries is opaque for me.

Maybe it's just a different perspective - as a developer systemd likely eases a lot of pains and makes otherwise problematic and error-prone problems easy but as an sysadmin that mostly deals with servers it feels sometimes like forced unnecessary complexity that can introduce difficult to debug issues.

gtaylor11y ago

As a sysadmin, I'll take systemd units over SysV init scripts any day. They tend to be shorter, more simple to read, and I don't have to worry about the race conditions or services not restarting correctly due to varying daemonization techniques.

nisa11y ago

Yes. I don't intended to argue about that. For that systemd is perfect and I like using it too. I mean such problems as a hanging boot in an lxc-container where I've once got only a (not a lot on google about that at this time) red error message that something went wrong. How to go from there? It's sure possible but it's a lot of work.

I don't say that's the norm and I don't say this happens often but if you build custom stuff and do "strange" things it's easier to know what's going on if you grasp the complete system. This is more difficult with systemd.

I believe it's a valid criticism and I realize 95% of users never need to care about this. However it's still a valid point if you build complex systems that are not "off the shelf".

sergiosgc11y ago

>And yes, bugs happen. But fixing the C code, is in my experience, much easier than tracking them down in `bash -x`. Especially when dealing with race conditions between services/triggers/device initialization.

You are being stubborn just for the sake of winning an argument. Interpreted languages are easier to debug. They have many flaws. Debugability isn't one of them. Heck, my servers don't even have gcc/gdb. Good luck trying to debug systemd in my production environments...

pdkl9511y ago

> fixing the C code, is in my experience, much easier

Really?

Did you account for the many very subtle ways you can run into what the C language defines as "undefined behavior"? I have only met a few programmers that truly understand that can of worms. Way too many don';t even know that compilers exploit these parts of the spec despite programming in C for many years.

http://blog.regehr.org/archives/213

http://blog.llvm.org/2011/05/what-every-c-programmer-should-...

That's just the cases where it it is totally legal for the compiler to output random noise - or output nothing at all - instead of what the C code says locally. These are some of the nastiest "gotchas" I've seen in any language.[1] Even the best C programmers are occasionally bit by this class of bug.

I still like C (a lot), but it is not easy. It's just so very annoying and time consuming to track down a bug happening in "foo.c" that is actually caused by a variable in "bar.c" didn't get updated waaaaaay earlier because some bit of code in "quux.c" was skipped over due to undefined behavior. Especially it becomes a heisenbug due to that particular optimization being turned off when in in debug builds.[2]

Bourne [Again] shell has its own share of quirks and "gotchas", but they are usually easy to investigate, and they are generally easy to avoid once you've written a couple scripts.

[1] There are other important classes of bug; I'm just using undefined behavior as an example because of how amazingly subtle it can be and how many serious security bugs it has caused.

[2] Before anybody complains that behavior involving 3 files like that is bad design, consider that A) this happens all the time in real world C, and B) I agree. Which is why many of us are against systemd, which adds complicated interactions like this on purpose as a way to force vertical integration.

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