Custom Insights events API
In addition to attaching custom parameters to the events that the Ruby agent generates automatically for each transaction, you can now record custom event types into Insights with the new NewRelic::Agent.record_custom_event API.
Reduced memory usage for idling applications
Idling applications using the agent could previously appear to leak memory because of native allocations during creation of new SSL connections to our servers. These native allocations didn't factor into triggering Ruby's garbage collector.
The agent will now re-use a single TCP connection to our servers for as long as possible, resulting in improved memory usage for applications that are idling and not having GC triggered for other reasons.
Don't write to stderr during CPU sampling
The Ruby agent's code for gathering CPU information would write error messages to stderr on some FreeBSD systems. This has been fixed.
LocalJumpError on Rails 2.x
Under certain conditions, Rails 2.x controller instrumentation could fail with a LocalJumpError when an action was not being traced. This has been fixed.
Fixed config lookup in warbler packaged apps
When running a Ruby application from a standalone warbler .jar file on JRuby, the packaged config/newrelic.yml was not properly found. This has been fixed, and thanks to Bob Beaty for the help getting it fixed!
Hash iteration failure in middleware
If a background thread iterated over the keys in the Rack env hash, it could cause failures in New Relic's AgentHooks middleware. This has been fixed.