Runtime Metrics Changes

new.txt

source=web.1 dyno=heroku.2808254.d97d0ea7-cf3d-411b-b453-d2943a50b456 sample#load_avg_1m=2.46 sample#load_avg_5m=1.06 sample#load_avg_15m=0.99

source=web.1 dyno=heroku.2808254.d97d0ea7-cf3d-411b-b453-d2943a50b456 sample#memory_total=21MB sample#memory_rss=21.22MB sample#memory_cache=0.00MB sample#memory_swap=0.00MB sample#memory_pgin=348836pages sample#memory_pgout=343403pages

old.txt

2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=load_avg_1m val=2.46
2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=load_avg_5m val=1.06
2013-03-11T20:23:40+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=load_avg_15m val=0.99
2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=memory_total val=21.22 units=MB
2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=memory_rss val=21.22 units=MB
2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=memory_cache val=0.00 units=MB
2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=memory_swap val=0.00 units=MB
2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=memory_pgpgin val=348836 units=pages
2013-03-15T23:10:13+00:00 heroku[web.1]: source=heroku.2808254.web.1.d97d0ea7-cf3d-411b-b453-d2943a50b456 measure=memory_pgpgout val=343403 units=pages

A few things to note when comparing the old vs. new:

• 9 lines => 2 lines. You could technically put all the measurements on a single line, I grouped them by memory and cpu.
• Breaking out source and dyno.web.1 is identifier used when scaling processes via the heroku cmd line. It is also the identifier used when grouping data in Librato. Thus source simply contains web.1. The UUID is moved into a separate k=v pair to ensure that the data is still there for support and debugging.
• Measurements prefixed with sample#. This indicates the the values should not be aggregated by average, median, p95, etc... It doesn't make any sense to know the 99th percentile of your 1m load average. A sample of the values is good enough.

Feedback from @dpiddy is that it would be very useful to include the app ID in the source column. I guess something like source=heroku.2808254.web.1 ?