disable deprecated runtime metrics by default

CHANGELOG.md

@@ -18,6 +18,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Changed
 
+- `go.opentelemetry.io/contrib/instrumentation/runtime` now produces the new metrics by default. Set `OTEL_GO_X_DEPRECATED_RUNTIME_METRICS=true` environment variable to additionally produce the deprecated metrics. (#7418)
 - The semantic conventions have been upgraded from `v1.30.0` to `v1.32.0` in `go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc`. (#7361)
 - The semantic conventions have been upgraded from `v1.26.0` to `v1.32.0` in `go.opentelemetry.io/contrib/detectors/aws/ec2`. (#7373)
 - The semantic conventions have been upgraded from `v1.26.0` to `v1.32.0` in `go.opentelemetry.io/contrib/detectors/aws/eks`. (#7375)

instrumentation/runtime/doc.go

@@ -5,6 +5,18 @@
 //
 // The metric events produced are:
 //
+//	go.memory.used          By            Memory used by the Go runtime.
+//	go.memory.limit         By            Go runtime memory limit configured by the user, if a limit exists.
+//	go.memory.allocated     By            Memory allocated to the heap by the application.
+//	go.memory.allocations   {allocation}  Count of allocations to the heap by the application.
+//	go.memory.gc.goal       By            Heap size target for the end of the GC cycle.
+//	go.goroutine.count      {goroutine}   Count of live goroutines.
+//	go.processor.limit      {thread}      The number of OS threads that can execute user-level Go code simultaneously.
+//	go.config.gogc          %             Heap size target percentage configured by the user, otherwise 100.
+//
+// When the OTEL_GO_X_DEPRECATED_RUNTIME_METRICS environment variable is set to
+// true, the following deprecated metrics are produced:
+//
 //	runtime.go.cgo.calls         -          Number of cgo calls made by the current process
 //	runtime.go.gc.count          -          Number of completed garbage collection cycles
 //	runtime.go.gc.pause_ns       (ns)       Amount of nanoseconds in GC stop-the-world pauses
@@ -19,16 +31,4 @@
 //	runtime.go.mem.heap_sys      (bytes)    Bytes of heap memory obtained from the OS
 //	runtime.go.mem.live_objects  -          Number of live objects is the number of cumulative Mallocs - Frees
 //	runtime.uptime               (ms)       Milliseconds since application was initialized
-//
-// When the OTEL_GO_X_DEPRECATED_RUNTIME_METRICS environment variable is set to
-// false, the metrics produced are:
-//
-//	go.memory.used          By            Memory used by the Go runtime.
-//	go.memory.limit         By            Go runtime memory limit configured by the user, if a limit exists.
-//	go.memory.allocated     By            Memory allocated to the heap by the application.
-//	go.memory.allocations   {allocation}  Count of allocations to the heap by the application.
-//	go.memory.gc.goal       By            Heap size target for the end of the GC cycle.
-//	go.goroutine.count      {goroutine}   Count of live goroutines.
-//	go.processor.limit      {thread}      The number of OS threads that can execute user-level Go code simultaneously.
-//	go.config.gogc          %             Heap size target percentage configured by the user, otherwise 100.
 package runtime // import "go.opentelemetry.io/contrib/instrumentation/runtime"

instrumentation/runtime/internal/x/README.md

@@ -13,22 +13,13 @@ change in backwards incompatible ways as feedback is applied.
 
 ### Include Deprecated Metrics
 
-Once new experimental runtime metrics are added, they will be produced
-**in addition to** the existing runtime metrics. Users that migrate right away
-can disable the old runtime metrics:
-
-```console
-export OTEL_GO_X_DEPRECATED_RUNTIME_METRICS=false
-```
-
-In a later release, the deprecated runtime metrics will stop being produced by
-default. To temporarily re-enable the deprecated metrics:
+To temporarily re-enable the deprecated metrics:
 
 ```console
 export OTEL_GO_X_DEPRECATED_RUNTIME_METRICS=true
 ```
 
-After two additional releases, the deprecated runtime metrics will be removed,
+Eventually, the deprecated runtime metrics will be removed,
 and setting the environment variable will no longer have any effect.
 
 The value set must be the case-insensitive string of `"true"` to enable the

instrumentation/runtime/internal/x/x.go

@@ -9,17 +9,17 @@ package x // import "go.opentelemetry.io/contrib/instrumentation/runtime/interna
 
 import (
 	"os"
-	"strings"
+	"strconv"
 )
 
 // DeprecatedRuntimeMetrics is an experimental feature flag that defines if the deprecated
 // runtime metrics should be produced. During development of the new
 // conventions, it is enabled by default.
 //
-// To disable this feature set the OTEL_GO_X_DEPRECATED_RUNTIME_METRICS environment variable
-// to the case-insensitive string value of "false" (i.e. "False" and "FALSE"
+// To enable this feature set the OTEL_GO_X_DEPRECATED_RUNTIME_METRICS environment variable
+// to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
 // will also enable this).
-var DeprecatedRuntimeMetrics = newFeature("DEPRECATED_RUNTIME_METRICS", true)
+var DeprecatedRuntimeMetrics = newFeature("DEPRECATED_RUNTIME_METRICS", false)
 
 // BoolFeature is an experimental feature control flag. It provides a uniform way
 // to interact with these feature flags and parse their values.
@@ -43,11 +43,11 @@ func (f BoolFeature) Key() string { return f.key }
 // Enabled returns if the feature is enabled.
 func (f BoolFeature) Enabled() bool {
 	v := os.Getenv(f.key)
-	if strings.ToLower(v) == "false" {
-		return false
-	}
-	if strings.ToLower(v) == "true" {
-		return true
+
+	val, err := strconv.ParseBool(v)
+	if err != nil {
+		return f.defaultVal
 	}
-	return f.defaultVal
+
+	return val
 }

instrumentation/runtime/internal/x/x_test.go

@@ -21,7 +21,7 @@ func TestDeprecatedRuntimeMetrics(t *testing.T) {
 	t.Run("False", run(setenv(key, "False"), assertEnabled(DeprecatedRuntimeMetrics, false)))
 	t.Run("FALSE", run(setenv(key, "FALSE"), assertEnabled(DeprecatedRuntimeMetrics, false)))
 	t.Run("1", run(setenv(key, "1"), assertEnabled(DeprecatedRuntimeMetrics, true)))
-	t.Run("empty", run(assertEnabled(DeprecatedRuntimeMetrics, true)))
+	t.Run("empty", run(assertEnabled(DeprecatedRuntimeMetrics, false)))
 }
 
 func run(steps ...func(*testing.T)) func(*testing.T) {

instrumentation/runtime/runtime.go

@@ -44,7 +44,9 @@
 		metric.WithInstrumentationVersion(Version()),
 	)
 	if x.DeprecatedRuntimeMetrics.Enabled() {
-		return deprecatedruntime.Start(meter, c.MinimumReadMemStatsInterval)
+		if err := deprecatedruntime.Start(meter, c.MinimumReadMemStatsInterval); err != nil {
+			return err
+		}
 	}
 	memoryUsed, err := goconv.NewMemoryUsed(meter)
 	if err != nil {

instrumentation/runtime/runtime_test.go

@@ -63,7 +63,6 @@ func TestRuntimeWithLimit(t *testing.T) {
 	// buffer for allocating memory
 	var buffer [][]byte
 	_ = allocateMemory(buffer)
-	t.Setenv("OTEL_GO_X_DEPRECATED_RUNTIME_METRICS", "false")
 	debug.SetMemoryLimit(1234567890)
 	// reset to default
 	defer debug.SetMemoryLimit(math.MaxInt64)