Sort Heroku logs chronologically

Question

Heroku is a hosting platform whose logs can be accessed via the heroku logs command line:

$ heroku logs
2014-07-17T06:24:02.216403+00:00 app[web.1]: Started
2014-07-17T06:24:02.216410+00:00 app[web.1]: Stopped
2014-07-17T06:24:02.216408+00:00 app[web.1]: Paused

As you can notice above, the chronological order is not respected.
Heroku is happy with that and gives no particular advice.

Is there any tool or bash script that I can use to have Heroku logs sorted?
The logs are pretty small, 1500 lines max.

Free, Open source, runs in Linux bash.

Answer 1

You could try this:

heroku logs > heroku.txt
sort -n -t\  -k1 heroku.txt

The -n is sorting numbers in order, -t\ bit is using a space as a separator, -k1 is using column one (the timestamp).

Without putting the logs in a separate file I assume you could use:

heroku logs | sort -n -t\  -k1

Similarly, to sort in reverse order (-nr):

heroku logs | sort -nr -t\  -k1

Answer 2

I wrote a little script to make live logs (heroku logs -t) sorted.

http://pastebin.com/8Lby3bMg

You can run with:

heroku logs -t | python delayed_sort.py

If you want to keep the coloring:

script -q -c "heroku logs -t" -a /dev/null | python delayed_sort.py

The script simply holds a buffer of the last 100 log lines. When the buffer gets full the line with the oldest timestamp is popped out (using heap-queue for efficiency...). The buffer is also flushed out when there are no new log lines for 1 second.

There is still a tiny chance that the lines will come out unsorted: a line with a timestamp that is older than the 100 preceding lines, or a line with an old timestamp after a 1 second communication pause.

Answer 3

As suggested by Gilles, this is the easiest and works flawlessly:

heroku logs | sort