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> Are you joining my side? No. As a user of many programs I always find it very frustrating when some program does not work and produce no log information wha

> Are you joining my side? No. As a user of many programs I always find it very frustrating when some program does not work and produce no log information whatsoever. As an engineer, I always write detailed and human-readable log entries with as much context as possible which is split into trace, debug, warning and info levels. With trace level enabled it's typically possible to reconstruct program execution step-to-step, which is _invaluable_ when you need to debug some rare problem. Even if logs are ephemeral and not persisted it's better to have logs for a run than not having logs at all. Logging as a side effect is irrelevant if you look at your code from the pragmatic standpoint, from which program execution transparency matters more than some abstract elegancy.

pletnes 7y ago
Interesting. How do you enable «trace-level» logging without writing «log.trace(...)» absolutely everywhere in your code? And what about performance? For context, I mostly program in python. I could imagine compile-time loglevel settings could address the performance, though.
- stickfigure 7y ago
  At least in Javaland, the "should I log" condition test for most logging libraries takes nanoseconds. Unless you're in an extremely tight loop, performance is fine.
  - benschulz 7y ago
    If it was absolutely necessary you could even have the JIT remove the code and then de-optimize when you enable tracing[1]. That would solve the tight-loop issue.. [1]: https://community.oracle.com/blogs/forax/2011/12/17/jsr-292-goodness-almost-static-final-field https://community.oracle.com/blogs/forax/2011/12/17/jsr-292-...
    - pkolaczk 7y ago
      Correct, in simple cases it can do it, but you need to be very careful with computing the arguments for the logging call. Java has no lazy evaluation of args nor macros, so if you accidentally concat strings there or do something expensive, it is likely JVM won't optimize these out. That's why typically you want to guard your logging calls on the hot path with an if condition.
- timeattack 7y ago
  I code mostly in Go. And yes, I'm writing `log.Tracef` everywhere. Might seem tedious, but in fact it's easily automated using snippets in the editor. Also when I'm inserting trace statements during development it provides a great help since it's much easier to debug logic. Regarding performance: I don't think that we need to worry about log performance. Most applications we have this days are not performance-bound to the logging. And all it takes to disable particular log level is single `if` in the code. Or a build flag in more extreme cases.

pletnes 7y ago

Interesting. How do you enable «trace-level» logging without writing «log.trace(...)» absolutely everywhere in your code? And what about performance? For context, I mostly program in python. I could imagine compile-time loglevel settings could address the performance, though.

stickfigure 7y ago
At least in Javaland, the "should I log" condition test for most logging libraries takes nanoseconds. Unless you're in an extremely tight loop, performance is fine.
- benschulz 7y ago
  If it was absolutely necessary you could even have the JIT remove the code and then de-optimize when you enable tracing[1]. That would solve the tight-loop issue.. [1]: https://community.oracle.com/blogs/forax/2011/12/17/jsr-292-goodness-almost-static-final-field https://community.oracle.com/blogs/forax/2011/12/17/jsr-292-...
  - pkolaczk 7y ago
    Correct, in simple cases it can do it, but you need to be very careful with computing the arguments for the logging call. Java has no lazy evaluation of args nor macros, so if you accidentally concat strings there or do something expensive, it is likely JVM won't optimize these out. That's why typically you want to guard your logging calls on the hot path with an if condition.
timeattack 7y ago
I code mostly in Go. And yes, I'm writing `log.Tracef` everywhere. Might seem tedious, but in fact it's easily automated using snippets in the editor. Also when I'm inserting trace statements during development it provides a great help since it's much easier to debug logic. Regarding performance: I don't think that we need to worry about log performance. Most applications we have this days are not performance-bound to the logging. And all it takes to disable particular log level is single `if` in the code. Or a build flag in more extreme cases.