Hello Yannick. Fortunately Kirk provided an answer on stackoverflow: https://stackoverflow.com/a/47597013/1265
Apparently the field name I'm looking for is "protoPayload.line.logMessage" which - unfortunately - isn't shown anywhere in the UI. I tried it out and it works as expected. I also suspect (though I didn't try this) that using the google-cloud-logging library (so not the built-in logging adapter) I could emit log messages with special fields that could be aggregated in a more straight-forward manner (without having to rely on the format of the log lines / regexes to parse them): https://googlecloudplatform.github.io/google-cloud-python/latest/logging/logger.html It would be really nice if this feature ("structured logging" integrated with log based metrics / stackdriver) would be offered out of the box, since monitoring is a big part of running an app in production. Attila -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/444eef99-0702-4212-938a-30fd88aa66df%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
