Rotating nohup.out without killing the application

I am looking for ideas on how to solve a problem with a nohup.out file
that is growing faster than expected.

While we change to a better logging mechanism we're using the stdout
to dump a bunch of debugging messages (a bunch is actually a lot!!).
Any hows, when the application runs for a few days the nohup.out file
could be 1G in size and to search for something on that file becomes a
pain in the neck.

The way I am doing that is pretty much manually. Stop the app, move
the file out and restart the app (using nohup).

I don't know if any of you guys know a better way to either rotate the
nohup.out (by date or size, don't care) or to redirect the stdout to a
logging application.

I have been looking around in the groups and on the net but can't find
anything that will give me some lights on how to do it.

Ciao,
Igor

igorojas@yahoo.com (igor) wrote in message news:<28c50361.0407071516.70f6ed19@posting.google. com>...
> I am looking for ideas on how to solve a problem with a nohup.out file
> that is growing faster than expected.

If the log file is too large, you could use the 'split' utility to
break it into pieces. For this example, I will create an empty "log"
file using 'dd' that is 4GiB in size, then split it into 512MiB
pieces:

$ dd if=/dev/zero bs=1024x1024 count=4096 > /var/log/app.log

$ split --bytes=512m /var/log/app.log /var/log/app.

$ ls -1 --size --human-readable /var/log/app.*

512Mi /var/log/app.aa
512Mi /var/log/app.ab
512Mi /var/log/app.ac
512Mi /var/log/app.ad
512Mi /var/log/app.ae
512Mi /var/log/app.af
512Mi /var/log/app.ag
512Mi /var/log/app.ah
4.0Gi /var/log/app.log

However, you probably want to do this while the log file is being
generated rather than wait until it gets to be 4.0GiB in size. So, use
a pipe:

$ nohup dd if=/dev/zero bs=1024x1024 count=4096 | split \
--bytes=512m - /var/log/app.

This time I used the '-' in place of the input file from above since I
want 'split' to read from the pipe instead. This will create log files
app.aa, app.ab, ... , each 512MiB in size -- choose a size that is
convenient for you.

You could then use 'find' to remove the old files automatically, to
put in your login script or in a cron job:

$ find /var/log/ -name "app.*" -atime +7 -and -mtime +7 \
-exec rm '{}' ';'

That will delete all log files that have the prefix 'app.' that have
not been accessed or modified in the last 7 days. So if a coworker is
still searching one of the log files frequently, it won't be deleted
when that command is run.