Here's what you need to do to get the New Relic plugin working with a Clojure/Pedestal app on Heroku.

heroku-clojure-newrelic-agent-log.bash

# How to configure a Clojure/Herokup app to use the New Relic add-on 
# for monitoring and to prevent the app from sleeping.
#
# by James Thornton, http://jamesthornton.com
# 

# Here's what you need to do to get the New Relic plugin working with a 
# Clojure/Pedestal app on Heroku.

# It took some fiddling because there are several versions of docs 
# floating around for setting up New Relic on a Clojure/Heroku dyno, 
# but none of them were quite right.
#
# See https://devcenter.heroku.com/articles/newrelic#clojure-configuration

# One of the docs said to add the newrelic.jar to the lib dir, but 
# don't do that because it will blow up the size of your repo. 


# First add the New Relic add on via the heroku command line client...

$ heroku addons:add newrelic:stark


# Your heroku config env vars when you added the New Relic plugin.... 

$ heroku config

=== myapp Config Vars
JVM_OPTS:              -Xmx400m
LEIN_NO_DEV:           true
NEW_RELIC_LICENSE_KEY: XXXXXXXXXXXXX
NEW_RELIC_LOG:         stdout
PATH:                  .lein/bin:/usr/local/bin:/usr/bin:/bin


# Make sure newrelic.yaml is in the root directory, and update it to include the value of your license_key...
# (see https://docs.newrelic.com/docs/java/java-agent-config-file-template)

$ grep key newrelic.yml
  # You must specify the license key associated with your New Relic
  # account.  This key binds your Agent's data to your account in the
  license_key: 'XXXXXXXXXXXXX'


# Make sure you're using at least version 3.2.0 of the newrelic-agent; there was a bug in version 3.1.1.
# Here's the relevant bits from my project.clj...

  :dependencies [ 
                 [environ "0.4.0"]
                 [com.newrelic.agent.java/newrelic-agent "3.2.0"]]

  :java-agents [[com.newrelic.agent.java/newrelic-agent "3.2.0"]]


# My Procfile looks like this...

$ cat Procfile
web: lein with-profile production trampoline run -m myapp.server


# Add a system.properties file to root to force Java 7...

$ cat system.properties 
java.runtime.version=1.7


# Add logs to .gitignore so you don't balloon your repo with local logs from running foreman...

$ cat .gitignore 
pom.xml
*jar
/classes/
/.lein-deps-sum
/.lein-failures
/.lein-env
/checkouts
/target
/logs 

# Then just add, commit, and push the config...

$ git add .
$ git commit -m "adds newrelic add on"
$ git push heroku master


# Check your logs as it starts to make sure it everything loads properly and doesn't timeout...

$ heroku logs -n 1000

2013-12-28T12:10:45.390680+00:00 heroku[web.1]: Starting process with command `lein with-profile production trampoline run -m myapp.server`
2013-12-28T12:10:47.315287+00:00 app[web.1]: Picked up JAVA_TOOL_OPTIONS:  -Djava.rmi.server.useCodebaseOnly=true
2013-12-28T12:10:51.658682+00:00 app[web.1]: Picked up JAVA_TOOL_OPTIONS:  -Djava.rmi.server.useCodebaseOnly=true
2013-12-28T12:10:52.250163+00:00 app[web.1]: Dec 28, 2013 12:10:52 +0000 NewRelic 1 INFO: Agent is using Logback
2013-12-28T12:10:52.503763+00:00 app[web.1]: Dec 28, 2013 12:10:52 +0000 NewRelic 1 INFO: Loading configuration file "newrelic.yml"
2013-12-28T12:10:53.095054+00:00 app[web.1]: Dec 28, 2013 12:10:53 +0000 NewRelic 1 INFO: Agent Host: 2c9a2 IP: 172.3.2.1
2013-12-28T12:10:53.597819+00:00 heroku[web.1]: source=web.1 dyno=heroku.1962 
2013-12-28T12:10:57.328065+00:00 app[web.1]: Dec 28, 2013 12:10:57 +0000 NewRelic 1 ERROR: javax/servlet/ServletOutputStream is marked as a weaved class, but no methods are matched to be weaved.
2013-12-28T12:10:57.329797+00:00 app[web.1]: Dec 28, 2013 12:10:57 +0000 NewRelic 1 ERROR: javax/servlet/ServletInputStream is marked as a weaved class, but no methods are matched to be weaved.
2013-12-28T12:11:07.053518+00:00 app[web.1]: Dec 28, 2013 12:11:06 +0000 NewRelic 1 INFO: Configured to connect to New Relic at collector.newrelic.com:443
2013-12-28T12:11:07.053518+00:00 app[web.1]: Dec 28, 2013 12:11:06 +0000 NewRelic 1 INFO: Setting audit_mode to false
2013-12-28T12:11:07.053518+00:00 app[web.1]: Dec 28, 2013 12:11:06 +0000 NewRelic 1 INFO: Setting protocol to "https"
2013-12-28T12:11:07.409930+00:00 app[web.1]: Dec 28, 2013 12:11:07 +0000 NewRelic 1 INFO: Configuration file is /app/newrelic.yml
2013-12-28T12:11:07.431577+00:00 app[web.1]: Dec 28, 2013 12:11:07 +0000 NewRelic 1 INFO: New Relic Agent v3.2.0 has started
2013-12-28T12:11:07.431801+00:00 app[web.1]: Dec 28, 2013 12:11:07 +0000 NewRelic 1 INFO: Agent class loader: sun.misc.Launcher$AppClassLoader@6b38dba
2013-12-28T12:11:07.431577+00:00 app[web.1]: Dec 28, 2013 12:11:07 +0000 NewRelic 1 INFO: Java version: 1.7.0_45
2013-12-28T12:11:14.332682+00:00 heroku[web.1]: source=web.1 dyno=heroku.1962
2013-12-28T12:11:20.236798+00:00 heroku[web.1]: State changed from starting to up
2013-12-28T12:11:19.830833+00:00 app[web.1]: INFO  org.eclipse.jetty.server.Server - jetty-8.1.9.v20130131
2013-12-28T12:11:19.903306+00:00 app[web.1]: Dec 28, 2013 12:11:19 +0000 NewRelic 1 INFO: Server Info: jetty/8.1.9.v20130131
2013-12-28T12:11:19.982817+00:00 app[web.1]: INFO  o.e.jetty.server.AbstractConnector - Started [email protected]:20987
2013-12-28T12:11:21.210603+00:00 app[web.1]: INFO  io.pedestal.service.http - {:line 64, :msg "GET /"}
2013-12-28T12:11:23.502916+00:00 app[web.1]: Dec 28, 2013 12:11:23 +0000 NewRelic 9 INFO: Collector redirection to collector-7.newrelic.com:443
2013-12-28T12:11:23.753969+00:00 app[web.1]: Dec 28, 2013 12:11:23 +0000 NewRelic 9 INFO: Agent run id: 683712260
2013-12-28T12:11:23.754626+00:00 app[web.1]: Dec 28, 2013 12:11:23 +0000 NewRelic 9 INFO: Agent 2@2c9/Example App connected to collector.newrelic.com:443
2013-12-28T12:11:23.765569+00:00 app[web.1]: Dec 28, 2013 12:11:23 +0000 NewRelic 9 INFO: Real user monitoring is enabled with auto instrumentation for application "Example App"
2013-12-28T12:11:23.769471+00:00 app[web.1]: Dec 28, 2013 12:11:23 +0000 NewRelic 9 INFO: Errors will be sent to New Relic for Example App

:dependencies doesn't have to be extended, only :java-agents.