> I am not entirely convinced by NB2. I am, in fact, a sort of sysadmin > person and most of my programs write to a log file. The programs are > also moderately complex, so a single program might access a database, > query an LDAP server, send email etc., so potentially quite a lot can go > wrong. They are also not programs whose output I would pipe to another > command. What would be the advantage of logging to stderr? Quite apart > from that, I find having a log file a useful for debugging when I am > developing.
First, the problem with writing to files is that there is no way to make these logs reliable. This is what I mean by saying these are unreliable: since logs are designed to grow indefinitely, the natural response to this design property is log rotation. But, it's impossible to reliably rotate a log file. There's always a chance that during the rotation some log entries will be written to the file past the point of rotation, but prior to the point where the next logs volume starts. There are similar reliability problems with writing to Unix or Internet sockets, databases etc. For different reasons, but at the end of the day, whoever wants logs, they want them to be reliable. Both simplicity and convention selected for stderr as the only and the best source of logging output. Programs that write their output to log files will always irritate their users because users will have to do some detective work to figure out where those files are, and in some cases they will have to do administrative works to make sure that the location where the program wants to store the log files is accessible, has enough free space, is speedy enough etc. So, from the ops perspective, whenever I come across a program that tries to write logs to anything other than stderr, I make an earnest effort to throw that program into the gutter and never touch it again. It's too much headache to babysit every such program, to remember the location of the log files of every such program, the required permissions, to provision storage. If you are in that line of work, you just want all logs to go to the same place (journal), where you can later filter / aggregate / correlate and perform other BI tasks as your heart desires. Of course, if you only administer your own computer, and you have low single digits programs to run, and their behavior doesn't change frequently, and you don't care to drop some records every now and then... it's OK to log to files directly from a program. But then you aren't really in the sysadmin / infra / ops category, as you are more of a hobby enthusiast. Finally, if you want your logs to go to a file, and currently, your only option is stderr, your shell gives you a really, really simple way of redirecting stderr to a file. So, really, there aren't any excuses to do that. -- https://mail.python.org/mailman/listinfo/python-list
