Go release notes

3.8.0

Changes

• When marking a transaction as a web transaction using Transaction.SetWebRequest, it is now possible to include a Host field in the WebRequest struct, which defaults to the empty string.

Bug Fixes

• The Host header is now being correctly captured and recorded in the request.headers.host attribute, as described here.
• Previously, the timestamps on Spans and Transactions were being written using different data types, which sometimes caused rounding errors that could cause spans to be offset incorrectly in the UI. This has been fixed.

3.6.0

New Features

• Added support for adding custom attributes directly to spans. These attributes will be visible when looking at spans in the distributed tracing UI.

  Example:

  txn := newrelic.FromContext(r.Context())
  sgmt := txn.StartSegment("segment1")
  defer sgmt.End()
  sgmt.AddAttribute("mySpanString", "hello")
  sgmt.AddAttribute("mySpanInt", 123)
  

• Custom attributes added to the transaction with txn.AddAttribute are now also added to the root span and will be visible when looking at the span in the distributed tracing UI. These custom attributes can be disabled from all destinations using Config.Attributes.Exclude or disabled from spans specifically using Config.SpanEvents.Attributes.Exclude.

• Agent attributes added to the transaction are now also added to the root span event and will be visible when looking at the span in the distributed tracing UI. These attributes include the request.uri and the request.method along with all other attributes listed in the attributes section of our godocs. These agent attributes can be disabled from all destinations using Config.Attributes.Exclude or disabled from spans specifically using Config.SpanEvents.Attributes.Exclude.

Bug Fixes

• Fixed an issue where it was impossible to exclude the attributes error.class and error.message from the root span. This issue has now been fixed. These attributes can now be excluded from all spans using Config.Attributes.Exclude or Config.SpanEvents.Attributes.Exclude.

• Fixed an issue that caused Go's data race warnings to trigger in certain situations when using the newrelic.NewRoundTripper. There were no reports of actual data corruption, but now the warnings should be resolved. Thank you to @blixt for bringing this to our attention!

3.4.0

New Features

• Attribute http.statusCode has been added to external span events representing the status code on an http response. This attribute will be included when added to an ExternalSegment in one of these three ways:

  1. Using NewRoundTripper with your http.Client
  2. Including the http.Response as a field on your ExternalSegment
  3. Using the new ExternalSegment.SetStatusCode API to set the status code directly

  To exclude the http.statusCode attribute from span events, update your agent configuration like so, where cfg is your newrelic.Config object.

  cfg.SpanEvents.Attributes.Exclude = append(cfg.SpanEvents.Attributes.Exclude, newrelic.SpanAttributeHTTPStatusCode)
  

• Error attributes error.class and error.message are now included on the span event in which the error was noticed, or on the root span if an error occurs in a transaction with no segments (no chid spans). Only the most recent error information is added to the attributes; prior errors on the same span are overwritten.

  To exclude the error.class and/or error.message attributes from span events, update your agent configuration like so, where cfg is your newrelic.Config object.

  cfg.SpanEvents.Attributes.Exclude = append(cfg.SpanEvents.Attributes.Exclude, newrelic.newrelic.SpanAttributeErrorClass, newrelic.SpanAttributeErrorMessage)
  

Changes

• Use Context.FullPath() for transaction names when using Gin version 1.5.0 or greater. Gin transactions were formerly named after the Context.HandlerName(), which uses reflection. This change improves transaction naming and reduces overhead. Please note that because your transaction names will change, you may have to update any related dashboards and alerts to match the new name.

  // Transactions previously named
  "GET main.handleGetUsers"
  // will be change to something like this match the full path
  "GET /user/:id"
  

3.2.0

New Features

• Added support for v7 of go-redis/redis in the new v3/integrations/nrredis-v7 package.
  • Documentation
  • Example

Changes

• Updated Gorilla instrumentation to include request time spent in middlewares. Added new nrgorilla.Middleware and deprecated nrgorilla.InstrumentRoutes. Register the new middleware as your first middleware using Router.Use. See the godocs examples for more details.

  r := mux.NewRouter()
  // Always register the nrgorilla.Middleware first.
  r.Use(nrgorilla.Middleware(app))
  
  // All handlers and custom middlewares will be instrumented.  The
  // transaction will be available in the Request's context.
  r.Use(MyCustomMiddleware)
  r.Handle("/", makeHandler("index"))
  
  // The NotFoundHandler and MethodNotAllowedHandler must be instrumented
  // separately using newrelic.WrapHandle.  The second argument to
  // newrelic.WrapHandle is used as the transaction name; the string returned
  // from newrelic.WrapHandle should be ignored.
  _, r.NotFoundHandler = newrelic.WrapHandle(app, "NotFoundHandler", makeHandler("not found"))
  _, r.MethodNotAllowedHandler = newrelic.WrapHandle(app, "MethodNotAllowedHandler", makeHandler("method not allowed"))
  
  http.ListenAndServe(":8000", r)
  

Known Issues and Workarounds

If a .NET agent is initiating distributed traces as the root service, you must update that .NET agent to version 8.24 or later before upgrading your downstream Go New Relic agents to this agent release.