Hi Graham, thanks for your response. Sorry I wasn't specific enough, I am logging to a single log file using the WatchedFileHandler to avoid issues with log file creation and rotation. As I understand, writing to a single file from multiple processes could cause logs getting mixed up if two processes write at the same time, I couldn't replicate it though. I believe that the same could happen if I log to stderr. I couldn't find if Apache uses some coordination mechanism for outputting the stderr streams of multiple processes to a single Apache error log file.
I am going to log to stderr as it seems to be working for most people but do you know of any documentation on how Apache handles this? Haven't found any and I would like to read up on it On Wednesday, 26 October 2022 at 17:56:10 UTC-3 Graham Dumpleton wrote: > Most people would just log to stdout/stderr which means log output gets > routed into the Apache error log files. Apache's mechanism for handling log > files when multiple processes are present seems to work fine. If you have > multiple sites on the Apache server then configure Apache to use different > log files for each VirtualHost as a way of keeping log files for different > application separate. > > Is there a specific reason you are using Python logging system mechanisms > to write to distinct log files (if that is what you meant you are doing)? > > Note that most issues with using a single log file for multiple processes > revolve around initial log file creation and log file rotation. In Apache > log files are initially created from the parent process so there is no race > condition on creation. It has a means to handle log file rotation as well, > although many Linux systems rely on log rotate service instead. > > Graham > > On 27 Oct 2022, at 5:50 am, Steve <est...@gmail.com> wrote: > > Hi, I am running a Flask app using mod_wsgi and I've been logging to a > file. The issue is now I need to run it using multiple processes but > multiple processes logging to a file without coordination is not a good > idea. > > Has anyone heard of a success case where they log to stderr with multiple > processes? That's the approach that I am hoping to take as other approaches > seem too overkill as of right now because they require to spin up some > service independent of the Flask app to handle the logs. > > And another question, does mod_wsgi do something special with opened files > with multiple processes? As I have tested logging with multiple processes > to the same file and have not found any issues. > > Thanks! > > > > -- > You received this message because you are subscribed to the Google Groups > "modwsgi" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to modwsgi+u...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/modwsgi/71b85a03-2818-4492-bbe2-b61344746948n%40googlegroups.com > > <https://groups.google.com/d/msgid/modwsgi/71b85a03-2818-4492-bbe2-b61344746948n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- You received this message because you are subscribed to the Google Groups "modwsgi" group. To unsubscribe from this group and stop receiving emails from it, send an email to modwsgi+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/modwsgi/7bc2d5da-e26b-44a8-9710-10241f0dfe79n%40googlegroups.com.
