Custom Annotations for Heroku Addons — Librato Blog

Custom Annotations for Heroku Addons

Heroku addon customers have enjoyed the convenience of our Release Annotations for tracking and correlating code deploys with the rest of their performance metrics. This week we're pleased to announce the release of Custom Annotations.

Custom Annotations

Annotations are a great way to identify and correlate a point-in-time event with all of your other time-series metrics within Librato. Adding the ability for Heroku users to create their own custom annotations means that you're no longer constrained to just tracking regressions and performance trends associated with Heroku releases. Anything that you might want to correlate with your metrics is now at your fingertips: sales promotions, user signups, etc - you're only limited by your own imagination.

Heroku customers on our Bronze plan and higher can send an unlimited number of custom annotations using the same log format as our custom metrics, but with the event keyword. For example, to record an annotation in Ruby when your code raises an exception:




We can see that the annotation was received by Librato with a key of exception and a value of Foo::Bar:

We also support optional fields including description, link, start_time, end_time, and source. Links are in the format of link#<rel>=<url>, where the rel describes the relationship of the link. Custom annotations support multiple links per event, however each link’s relationship must be unique within a single annotation event.


$stdout.puts('event#signup="New User" description="John Doe signed up via web" link#metrics="" start_time=1234567890 end_time=9876543210 source=us-east')


Like before, we can see that the annotation was received. This time it came in with a key of signup and a value of New User . In addition, it also recorded the source (us-east), our description ("John Doe signed up via web"), and a link to the relevant site or documentation.

If you have any questions about the Librato Add-On for Heroku, please check out the official documentation in the Heroku Dev Center. Of course, you can also find us online in our support chat or email us at