Fix semconv instrument types (#6837)

- The instrument type for `goconv.MemoryUsed` need to be an
`Int64ObservableUpDownCounter`, not an `Int64ObservableCounter`
[according to semantic
conventions](ca0c5ada95/docs/runtime/go-metrics.md (metric-gomemoryused))
- The instrument type for `systemconv.MemoryUsage` need to be an
`Int64ObservableUpDownCounter`, not an `Int64ObservableGauge` [according
to semantic
conventions](ca0c5ada95/docs/system/system-metrics.md (metric-systemmemoryusage))

All other [metric instrument type
overrides](6e90db55ca/semconv/weaver.yaml (L70-L83))
have be verified.

semconv/v1.33.0/MIGRATION.md

@@ -2,6 +2,18 @@
 
 The `go.opentelemetry.io/otel/semconv/v1.33.0` package should be a drop-in replacement for `go.opentelemetry.io/otel/semconv/v1.32.0` with the following exceptions.
 
+## Metric instrument type fixes
+
+### `goconv.MemoryUse`
+
+The underlying metric instrument type for `goconv.MemoryUse` has been corrected be an `Int64ObservableUpDownCounter` instead of an `Int64ObservableCounter`.
+This change aligns with the semantic conventions for memory usage metrics.
+
+### `systemconv.MemoryUsage`
+
+The underlying metric instrument type for `systemconv.MemoryUsage` has been corrected be an `Int64ObservableUpDownCounter` instead of an `Int64ObservableGauge`.
+This change aligns with the semantic conventions for memory usage metrics.
+
 ## Dropped deprecations
 
 The following declarations have been deprecated in the [OpenTelemetry Semantic Conventions].

semconv/v1.33.0/goconv/metric.go

@@ -335,35 +335,35 @@ func (MemoryLimit) Description() string {
 // "go.memory.used" semantic conventions. It represents the memory used by the Go
 // runtime.
 type MemoryUsed struct {
-	metric.Int64ObservableCounter
+	metric.Int64ObservableUpDownCounter
 }
 
 // NewMemoryUsed returns a new MemoryUsed instrument.
 func NewMemoryUsed(
 	m metric.Meter,
-	opt ...metric.Int64ObservableCounterOption,
+	opt ...metric.Int64ObservableUpDownCounterOption,
 ) (MemoryUsed, error) {
 	// Check if the meter is nil.
 	if m == nil {
-		return MemoryUsed{noop.Int64ObservableCounter{}}, nil
+		return MemoryUsed{noop.Int64ObservableUpDownCounter{}}, nil
 	}
 
-	i, err := m.Int64ObservableCounter(
+	i, err := m.Int64ObservableUpDownCounter(
 		"go.memory.used",
-		append([]metric.Int64ObservableCounterOption{
+		append([]metric.Int64ObservableUpDownCounterOption{
 			metric.WithDescription("Memory used by the Go runtime."),
 			metric.WithUnit("By"),
 		}, opt...)...,
 	)
 	if err != nil {
-	    return MemoryUsed{noop.Int64ObservableCounter{}}, err
+	    return MemoryUsed{noop.Int64ObservableUpDownCounter{}}, err
 	}
 	return MemoryUsed{i}, nil
 }
 
 // Inst returns the underlying metric instrument.
-func (m MemoryUsed) Inst() metric.Int64ObservableCounter {
-	return m.Int64ObservableCounter
+func (m MemoryUsed) Inst() metric.Int64ObservableUpDownCounter {
+	return m.Int64ObservableUpDownCounter
 }
 
 // Name returns the semantic convention name of the instrument.

semconv/v1.33.0/systemconv/metric.go

@@ -1484,35 +1484,35 @@ func (m MemoryShared) Add(ctx context.Context, incr int64, attrs ...attribute.Ke
 // "system.memory.usage" semantic conventions. It represents the reports memory
 // in use by state.
 type MemoryUsage struct {
-	metric.Int64ObservableGauge
+	metric.Int64ObservableUpDownCounter
 }
 
 // NewMemoryUsage returns a new MemoryUsage instrument.
 func NewMemoryUsage(
 	m metric.Meter,
-	opt ...metric.Int64ObservableGaugeOption,
+	opt ...metric.Int64ObservableUpDownCounterOption,
 ) (MemoryUsage, error) {
 	// Check if the meter is nil.
 	if m == nil {
-		return MemoryUsage{noop.Int64ObservableGauge{}}, nil
+		return MemoryUsage{noop.Int64ObservableUpDownCounter{}}, nil
 	}
 
-	i, err := m.Int64ObservableGauge(
+	i, err := m.Int64ObservableUpDownCounter(
 		"system.memory.usage",
-		append([]metric.Int64ObservableGaugeOption{
+		append([]metric.Int64ObservableUpDownCounterOption{
 			metric.WithDescription("Reports memory in use by state."),
 			metric.WithUnit("By"),
 		}, opt...)...,
 	)
 	if err != nil {
-	    return MemoryUsage{noop.Int64ObservableGauge{}}, err
+	    return MemoryUsage{noop.Int64ObservableUpDownCounter{}}, err
 	}
 	return MemoryUsage{i}, nil
 }
 
 // Inst returns the underlying metric instrument.
-func (m MemoryUsage) Inst() metric.Int64ObservableGauge {
-	return m.Int64ObservableGauge
+func (m MemoryUsage) Inst() metric.Int64ObservableUpDownCounter {
+	return m.Int64ObservableUpDownCounter
 }
 
 // Name returns the semantic convention name of the instrument.

semconv/v1.34.0/goconv/metric.go

@@ -335,35 +335,35 @@ func (MemoryLimit) Description() string {
 // "go.memory.used" semantic conventions. It represents the memory used by the Go
 // runtime.
 type MemoryUsed struct {
-	metric.Int64ObservableCounter
+	metric.Int64ObservableUpDownCounter
 }
 
 // NewMemoryUsed returns a new MemoryUsed instrument.
 func NewMemoryUsed(
 	m metric.Meter,
-	opt ...metric.Int64ObservableCounterOption,
+	opt ...metric.Int64ObservableUpDownCounterOption,
 ) (MemoryUsed, error) {
 	// Check if the meter is nil.
 	if m == nil {
-		return MemoryUsed{noop.Int64ObservableCounter{}}, nil
+		return MemoryUsed{noop.Int64ObservableUpDownCounter{}}, nil
 	}
 
-	i, err := m.Int64ObservableCounter(
+	i, err := m.Int64ObservableUpDownCounter(
 		"go.memory.used",
-		append([]metric.Int64ObservableCounterOption{
+		append([]metric.Int64ObservableUpDownCounterOption{
 			metric.WithDescription("Memory used by the Go runtime."),
 			metric.WithUnit("By"),
 		}, opt...)...,
 	)
 	if err != nil {
-	    return MemoryUsed{noop.Int64ObservableCounter{}}, err
+	    return MemoryUsed{noop.Int64ObservableUpDownCounter{}}, err
 	}
 	return MemoryUsed{i}, nil
 }
 
 // Inst returns the underlying metric instrument.
-func (m MemoryUsed) Inst() metric.Int64ObservableCounter {
-	return m.Int64ObservableCounter
+func (m MemoryUsed) Inst() metric.Int64ObservableUpDownCounter {
+	return m.Int64ObservableUpDownCounter
 }
 
 // Name returns the semantic convention name of the instrument.

semconv/v1.34.0/systemconv/metric.go

@@ -1484,35 +1484,35 @@ func (m MemoryShared) Add(ctx context.Context, incr int64, attrs ...attribute.Ke
 // "system.memory.usage" semantic conventions. It represents the reports memory
 // in use by state.
 type MemoryUsage struct {
-	metric.Int64ObservableGauge
+	metric.Int64ObservableUpDownCounter
 }
 
 // NewMemoryUsage returns a new MemoryUsage instrument.
 func NewMemoryUsage(
 	m metric.Meter,
-	opt ...metric.Int64ObservableGaugeOption,
+	opt ...metric.Int64ObservableUpDownCounterOption,
 ) (MemoryUsage, error) {
 	// Check if the meter is nil.
 	if m == nil {
-		return MemoryUsage{noop.Int64ObservableGauge{}}, nil
+		return MemoryUsage{noop.Int64ObservableUpDownCounter{}}, nil
 	}
 
-	i, err := m.Int64ObservableGauge(
+	i, err := m.Int64ObservableUpDownCounter(
 		"system.memory.usage",
-		append([]metric.Int64ObservableGaugeOption{
+		append([]metric.Int64ObservableUpDownCounterOption{
 			metric.WithDescription("Reports memory in use by state."),
 			metric.WithUnit("By"),
 		}, opt...)...,
 	)
 	if err != nil {
-	    return MemoryUsage{noop.Int64ObservableGauge{}}, err
+	    return MemoryUsage{noop.Int64ObservableUpDownCounter{}}, err
 	}
 	return MemoryUsage{i}, nil
 }
 
 // Inst returns the underlying metric instrument.
-func (m MemoryUsage) Inst() metric.Int64ObservableGauge {
-	return m.Int64ObservableGauge
+func (m MemoryUsage) Inst() metric.Int64ObservableUpDownCounter {
+	return m.Int64ObservableUpDownCounter
 }
 
 // Name returns the semantic convention name of the instrument.

semconv/weaver.yaml

@@ -75,10 +75,10 @@ text_maps:
     go.memory.allocations: Int64ObservableCounter
     go.memory.gc.goal: Int64ObservableUpDownCounter
     go.memory.limit: Int64ObservableUpDownCounter
-    go.memory.used: Int64ObservableCounter
+    go.memory.used: Int64ObservableUpDownCounter
     go.processor.limit: Int64ObservableUpDownCounter
     process.cpu.time: Float64ObservableCounter
-    system.memory.usage: Int64ObservableGauge
+    system.memory.usage: Int64ObservableUpDownCounter
     system.memory.utilization: Float64ObservableGauge
     system.network.io: Int64ObservableCounter
 acronyms: