Is there some conversation somewhere that I've missed as to why this logger is better than other loggers, or where we decided to change?

Is there some conversation somewhere that I've missed as to why this logger is better than other loggers, or where we decided to change?

#3428 although the title says zap the conversation says zero log. Also apps can easily override, and many do, the logger. I would say this is more of reducing maintenance burden of a custom logger.

No major discussions @tychoish. We expose a Logger interface that applications can use to implement/provide whatever loggers they like (SDK uses zerolog).

Tendermint implements a "default" one, but it was an archaic and convoluted series of wrappers around go-kit and very slow compared to zerolog, which is very performant and has good ergonomics.

We need the logger to be thread-safe, which zerolog supports...I'm gonna put this PR on pause.

not that logging performance is really ever an issue, but...

It has caused issues in the past at least in some testing areas.

Not sure that there needs to be a further discussion here, does there? The pr is already here, lets just wrap it up and merge it. Less code is always better, IMO.

It has caused issues in the past at least in some testing areas.

The testing logger problem is almost certainly not about the raw speed of the logger and rather about the volume of log messages when the system runs quickly (combined with the way that the testing logger writes to standard output, and the logger is multiplexed between tests.

I agree, however, that this is a fine change.

It's a win for two reasons: (1) We have a more performant logger (which does matter, albeit can be little), and (2) we removed +1k lines of useless code.

Yeah, let's do it.

Codecov Report

Merging #6534 (2f572b7) into master (eaa0468) will decrease coverage by 0.05%.
The diff coverage is 39.70%.

@@            Coverage Diff             @@
##           master    #6534      +/-   ##
==========================================
- Coverage   60.50%   60.44%   -0.06%     
==========================================
  Files         299      294       -5     
  Lines       27883    27703     -180     
==========================================
- Hits        16870    16746     -124     
+ Misses       9296     9251      -45     
+ Partials     1717     1706      -11     

NOTE: This removes the ability for Tendermint's default logger to provide field filtering, e.g. abci:info.

docs need to be updated to reflect this. Mainly logging.md