bmcweb logging

[Andrei Kartashev]

Hi Ed,

I disagree with you here. Once we have logs I expect to see errors
information by default. I'm not gonna to build applications with
verbose logging unless I debug it but but bugs could appears even you
are not looking for them ;). Logging unusual/unexpected behaviour by
default typically helps to localize problem.
So I believe, we should formalize and cleanup log level usage.


On Thu, 2020-10-29 at 09:22 -0700, Ed Tanous wrote:
> On Thu, Oct 29, 2020 at 8:47 AM Ratan Gupta <
> ratagupt at linux.vnet.ibm.com> wrote:
> > Hi Ed,
> > 
> > I was having issues in getting the logs from bmcweb repo, If I
> > don't
> > define the compiler flag(BMCWEB_ENABLE_LOGGING) then it doesn't get
> > me
> > any logs in journal(not even error log) and if I define the
> > compiler
> > flag then it gets too much debug info.
> 
> What's your limit for "too much"?
> 
> > Seems it happens because we have hardcoded the logelevel  and there
> > is
> > no way through which we can change except making the change
> > manually in
> > the following place.
> > 
> > https://github.com/openbmc/bmcweb/blob/master/http/logging.hpp#L93
> > 
> > Suggestion is we can define another compile time flag for log level
> > and
> > use that log level at the above line for type of logging , by
> > default
> > logging should be enabled with error log level.
> 
> Thusfar, we don't really have a definition of what kind of detail
> should be included at each log level, nor are we consistent about
> setting the log levels.  If it's important to you, and you want to
> put
> together some patches, we certainly could define the log verbosity,
> but we'd also have to come up with better definitions for what level
> each log needs to take, and be more consistent about it.
> 
> IMO, that level of log granularity was never that valuable to debug,
> my thought being that if I'm enabling logging I don't care about
> performance, so the more logs the better.  When reproducing a
> failure,
> there doesn't tend to be a lot of logging present, and it's easy
> enough to find what you want, but maybe you had a different
> experience?
> 
> Long term, my intent was to just get rid of the various verbosities,
> and make logging ON or OFF in the code, and downgrade to a single
> macro, but if you see a need, we could certainly go the other
> direction.
> 
> > If there is a need user can play with new compiler flag for more
> > verbose
> > logging.
> 
> I don't personally see the need, but if it would help you, I don't
> think it adds much complexity to do it, and I'd be happy to review
> your patches.
> 
> > Am I missing something in usage of logging infra?
> > 
> > Ratan
> > 
> > 
> 
> Just to be clear, you're using logging in a debug context, correct?
> If we're trying to use this to define an access log, that's a very
> different problem space, and the existing logging infrastructure
> would
> be poorly suited for it.
-- 
Best regards,
Andrei Kartashev