New Relic Ruby Agent Release Notes

• Error attributes now added to each span that exits with an error or exception

  Error attributes error.class and error.message are now included on the span event in which an error or exception was noticed, and, in the case of unhandled exceptions, on any ancestor spans that also exit with an error. The public API method notice_error now attaches these error attributes to the currently executing span.

  Spans with error details are now highlighted red in the Distributed Tracing UI, and error details will expose the associated error.class and error.message. It is also now possible to see when an exception leaves the boundary of the span, and if it is caught in an ancestor span without reaching the entry span. NOTE: This “bubbling up” of exceptions will impact the error count when compared to prior behavior for the same trace. It is possible to have a trace that now has span errors without the trace level showing an error.

  If multiple errors occur on the same span, only the most recent error information is added to the attributes. Prior errors on the same span are overwritten.

  These span event attributes conform to ignored errors and expected errors.

• Added tests for latest Grape / Rack combination

  For a short period of time, the latest versions of Grape and Rack had compatibility issues. Generally, Rack 2.1.0 should be avoided in all cases due to breaking changes in many gems reliant on Rack. We recommend using either Rack <= 2.0.9, or using latest Rack when using Grape (2.2.2 at the time of this writing).

• Bugfix: Calculate Content-Length in bytes

  Previously, the Content-Length HTTP header would be incorrect after injecting the Browser Monitoring JS when the response contained Unicode characters because the value was not calculated in bytes. The Content-Length is now correctly updated.

  Thanks to thaim for the contribution!

• Bugfix: Fix Content-Length calculation when response is nil

  Previously, calculating the Content-Length HTTP header would result in a NoMethodError in the case of a nil response. These errors will no longer occur in such a case.

  Thanks to Johan Van Ryseghem for the contribution!

• Bugfix: DecoratingFormatter now logs timestamps as millisecond Integers

  Previously the agent sent timestamps as a Float with milliseconds as part of the fractional value. Logs in Context was changed to only accept Integer values and this release changes DecoratingFormatter to match.

• Added --force option to newrelic install cli command to allow overwriting newrelic.yml

• Bugfix: The fully qualified hostname now works correctly for BSD and Solaris

  Previously, when running on systems such as BSD and Solaris, the agent was unable to determine the fully qualified domain name, which is used to help link Ruby agent data with data from New Relic Infrastructure. This information is now successfully collected on various BSD distros and Solaris.

v6.8.0

• Initial Ruby 2.7 support

  The Ruby agent has been verified to run with Ruby 2.7.0-preview1.

• New API method to add custom attributes to Spans

  New API method for adding custom attributes to spans. Previously, custom attributes were only available at the Transaction level. Now, with Span level custom attributes, more granular tagging is possible for easier isolation and review of traces. For more information:

  • Agent#add_custom_span_attributes

• Enables ability to migrate to configurable security policies (CSP) on a per-agent basis for accounts already using high security mode (HSM).

  When both HSM and CSP are enabled for an account, an agent (this version or later) can successfully connect with either high_security: true or the appropriate security_policies_token configured. high_security has been added as part of the preconnect payload.

• Bugfix for logs-in-context combined with act-fluent-logger-rails

  Previously, when using the Ruby agent's logs-in-context logger to link logging data with trace and entity metadata for an improved experience in the UI, customers who were also using the act-fluent-logger-rails gem would see a NoMethodError for clear_tags! that would interfere with the use of this feature. This error no longer appears, allowing customers to combine the use of logs-in-context with the use of this gem.

  Please note that the logs-in-context logger does not support tagged logging; if you are initializing your logger with a log_tags argument, your custom tags may not appear on the final version of your logs.

• Bugfix for parsing invalid newrelic.yml

  Previously, if the newrelic.yml configuration file was invalid, and the agent could not start as a result, the agent would not log any indication of the problem.

  This version of the agent will emit a FATAL message to STDOUT when this scenario occurs so that customers can address issues with newrelic.yml that prevent startup.

• Configuration options containing the terms "whitelist" and "blacklist" deprecated

  The following local configuration settings have been deprecated:

  • autostart.blacklisted_constants: use autostart.denylisted_constants instead.
  • autostart.blacklisted_executables: use autostart.denylisted_executables instead.
  • autostart.blacklisted_rake_tasks: use autostart.denylisted_rake_tasks instead.
  • strip_exception_messages.whitelist: use strip_exception_messages.allowed_classes instead.

• Bugfix for module loading and constant resolution in Rails

  Starting in version 6.3, the Ruby agent has caused module loading and constant resolution to sometimes fail, which caused errors in some Rails applications. These errors were generally NoMethodError exceptions or I18n errors translation missing or invalid locale. These errors would not appear if the agent was removed from the application's Gemfile. This version of the agent fixes these issues with module loading and constant resolution, so these errors no longer occur.

• Bugfix: failed to get urandom

  Previous versions of the agent would fail unexpectedly when the Ruby process used every available file descriptor. The failures would include this message:

  ERROR : RuntimeError: failed to get urandom
  

  This version of the agent uses a different strategy for generating random IDs, and will not fail in the same way when no file descriptors are available.

v6.6.0

• Bugfix for ActionCable Instrumentation

  Previous versions of the agent sometimes caused application crashes with some versions of ActionCable. The application would exit quickly after startup with the error: uninitialized constant ActionCable::Engine.

  Version 6.6.0 of the agent no longer crashes in this way.

• Handling of disabling Error Collection

  When the agent first starts, it begins collecting Error Events and Traces before fetching configuration from New Relic. In previous versions of the agent, those events or traces would be sent to New Relic, even if Error Collection is disabled in the application's server-side configuration.

  Version 6.6.0 of the agent drops all collected Error Events and Traces if the configuration from the server disables Error Collection.

v6.4.0

• Custom Metadata Collection

  The agent now collects environment variables prefixed by NEW_RELIC_METADATA_. These may be added to transaction events to provide context between your Kubernetes cluster and your services. For details on the behavior, see this blog post.

• Bugfix for faster ActiveRecord connection resolution

  Version 6.3.0 of the agent backported the faster ActiveRecord connection resolution from Rails 6.0 to previous versions, but the implementation caused certain other gems which measured ActiveRecord performance to stop working. This version of the agent changes the implementation of this performance improvement so no such conflicts occur.

• Bugfix for Grape instrumentation error

  Previous versions of the agent would fail to install Grape instrumentation in Grape versions 1.2.0 and up if the API being instrumented subclassed Grape::API::Instance rather than Grape::API. A warning would also print to the newrelic_agent log:

  WARN : Error in Grape instrumentation
  WARN : NoMethodError: undefined method `name' for nil:NilClass
  

  This version of the agent successfully installs instrumentation for subclasses of Grape::API::Instance, and these log messages should no longer appear.

• Bugfix for streaming responses

  Previous versions of the agent would attempt to insert JavaScript instrumentation into any streaming response that did not make use of ActionController::Live. This resulted in an empty, non-streamed response being sent to the client.

  This version of the agent will not attempt to insert JavaScript instrumentation into a response which includes the header Transfer-Encoding=chunked, which indicates a streaming response.

  This should exclude JavaScript instrumentation for all streamed responses. To include this instrumentation manually, see Manually instrument via agent API in our documentation.

v6.2.0

• Bugfix for superfluous Empty JSON response error messages

  Version 6.1.0 of the agent frequently logged error messages about an empty JSON response, when no error had occurred. These logs no longer appear.

• Bugfix for Unable to calculate elapsed transaction time warning messages

  Ruby Agent versions 5.4 through 6.1, when running in jruby without ObjectSpace enabled, would occasionally log a warning indicating that the agent was unable to calculate the elapsed transaction time. When this log statement appeared, the affected transactions would not be included in the data displayed on the capacity analysis page. These transactions are now correctly recorded.

v6.0.0

• Tracer API for flexible custom instrumentation

  With agent version 6.0, we are introducing the Tracer class, an officially supported public API for more flexible custom instrumentation. By calling its in_transaction method, you can instrument an arbitrary section of Ruby code without needing to juggle any explicit state. Behind the scenes, the agent will make sure that the measured code results in an APM segment inside a transaction.

  The same API contains additional methods for creating transactions and segments, and for interacting with the current transaction. For more details, see the custom instrumentation documentation.

  If you were previously using any of the agent's private, undocumented APIs, such as Transaction.wrap or Transaction.start/stop, you will need to update your code to use the Tracer API.

  The full list of APIs that were removed or deprecated are:

  • External.start_segment
  • Transaction.create_segment
  • Transaction.start
  • Transaction.stop
  • Transaction.start_datastore_segment
  • Transaction.start_segment
  • Transaction.wrap

  • TransactionState.current_transaction

    If are you using any of these APIs, please see the upgrade guide for a list of replacements.

• Agent detects Rails 6.0

  The agent properly detects Rails 6.0 and no longer logs an error when started in a Rails 6.0 environment. This does not include full Rails 6.0 support, which will be coming in a future release. Thanks to Jacob Bednarz for the contribution.

v5.6.0

• Bugfix for transactions with ActionController::Live

  Previously, transactions containing ActionController::Live resulted in incorrect calculations of capacity analysis as well as error backtraces appearing in agent logs in agent versions 5.4 and later. The agent now correctly calculates capacity for transactions with ActionController::Live.

• Add ability to exclude attributes from span events and transaction segments

  Agent versions 5.5 and lower could selectively exclude attributes from page views, error traces, transaction traces, and transaction events. With agent version 5.6 and higher, you can also exclude attributes from span events (via the span_events.include/exclude options) and from transaction segments (via the transaction_segments.include/exclude options).

  As with other attribute destinations, these new options will inherit values from the top-level attributes.include/exclude settings. See the documentation for more information.

• Increasing backoff sequence on failing to connect to New Relic

  If the agent cannot reach New Relic, it will now wait for an increasing amount of time after each failed attempt. We are also starting with a shorter delay initially, which will help customer apps bounce back more quickly from transient network errors.

• Truncation of long stack traces

  Previous versions of the agent would truncate long stack traces to 50 frames. To give customers more flexibility, we have added the error_collector.max_backtrace_frames configuration option. Thanks to Patrick Tulskie for the contribution!

• Update link in documentation

  The community forum link in README.md now goes to the updated location. Thanks to Sam Killgallon for the contribution!

• Active Storage instrumentation

  The agent now provides instrumentation for Active Storage, introduced in Rails 5.2. Customers will see Active Storage operations represented as segments within transaction traces.

v5.4.0

• Capacity analysis for multi-threaded dispatchers

  Metrics around capacity analysis did not previously account for multi-threaded dispatchers and consequently could result in capacities of over 100% being recorded. This version now properly accounts for multi-threaded dispatchers.

• NewRelic::Agent.disable_transaction_tracing deprecated

  NewRelic::Agent.disable_transaction_tracing has been deprecated. Users are encouraged to use NewRelic::Agent.disable_all_tracing or NewRelic::Agent.ignore_transaction instead.

• Bugfix for SQL over-obfuscation

  A bug, introduced in v5.3.0, where SQL could be over-obfuscated for some database adapters has been fixed.

• Bugfix for span event data in Resque processes

  Previously, some users encountered a bug where span events would not be sent from Resque processes due to a missing endpoint, resulting in errors containing the text NoMethodError: undefined method span_event_data.

  Span events can now be successfully sent from Resque processes.

v5.2.0

• Use priority sampling for errors and custom events

  Priority sampling replaces the older reservoir event sampling method. With this change, the agent will maintain randomness across a given time period while improving coordination among transactions, errors, and custom events.

• Bugfix for wrapping datastore operations

  The agent will now complete the process of wrapping datastore operations even if an error occurs during execution of a callback.