Logging sometimes reports wrong database in multisite


(Michael - DiscourseHosting.com) #1

I was investigating an issue and it seems like the lines in production.log sometimes report the wrong database.

I’ve seen this a few times before, so this is not a single incident. Here’s a good and clear example where you can see that the third line has been logged as belonging to database db3785 where it obviously is about the same request as the fourth line, which is logged as belonging to db9210.

I was unable to pinpoint the responsible code, it might be deep inside Rails, and this is probably a race condition.

v1.8.x on Unicorn.

No, we’re not using Docker, no, I don’t think that matters here, and no, I don’t expect a quick solution.
Just letting you guys know what we are seeing :slight_smile:


(Sam Saffron) #2

Rails logs are a trashfire, we plan to start using a new format in future


(Alan Tan) #6

I’ll put this on my list first, it seems like the connection is switched even before logging is complete.


(Sam Saffron) #7

This is really unsolvable with the current log format. @tgxworld is going to investigate making GitHub - roidrage/lograge: An attempt to tame Rails' default policy to log everything. an optional (and hopefully default) log format for rails to avoid this mess and give us properly parsable log files.


(Alan Tan) #8

Note that lograge can now be enabled via a hidden SiteSetting.logging_provider or setting ENABLE_LOGRAGE to 1. We’ll be testing this on our servers for awhile before deciding if lograge should be the default for all Discourse users.


(Jeff Atwood) #9

Is lograge the default now?


(Alan Tan) #10

Nope but we can make it so.