As was raised several times during Wikimania 2016 the current logs are huge* and essentially useless since we add all kinds of info to them therefore making it hard to find the actual errors.
The suggestions were to either:
- Rebuild the logging structure using something more advanced (sentry and X where mentioned)
- Use the levels implemented in pywikibot.logging
- Skip outputting various messages which we are often (but not always) not interested in or which are already logged on-wiki.
*Last I checked there were 1,932,469 lines (before the commonscat bit had finished) out of which 1,823,328 start with "Found unknown field on page".