[service] Move batchprocessor metrics to normal level and update leve…

…l guidelines

.chloggen/telemetry-level-update.yaml

@@ -0,0 +1,33 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: service
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Batch processor telemetry is no longer emitted at "basic" verbosity level
+
+# One or more tracking issues or pull requests related to the change
+issues: [7890]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  According to the guidelines, basic-level telemetry should be reserved for core Collector APIs.
+  Components such as the batch processor should emit telemetry starting from the "normal" level
+  (which is also the default level).
+
+  Migration: If your Collector telemetry was set to `level: basic` and you want to keep seeing
+  batch processor-related metrics, consider switching to `level: normal` instead.
+
+  
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

config/configtelemetry/configtelemetry.go

@@ -10,13 +10,13 @@ import (
 )
 
 const (
-	// LevelNone indicates that no telemetry data should be collected.
+	// LevelNone indicates that no telemetry should be collected.
 	LevelNone Level = iota - 1
-	// LevelBasic is the recommended and covers the basics of the service telemetry.
+	// LevelBasic indicates that only core Collector telemetry should be collected.
 	LevelBasic
-	// LevelNormal adds some other indicators on top of basic.
+	// LevelNormal indicates that all low-overhead telemetry should be collected.
 	LevelNormal
-	// LevelDetailed adds dimensions and views to the previous levels.
+	// LevelDetailed indicates that all available telemetry should be collected.
 	LevelDetailed
 
 	levelNoneStr     = "None"

config/configtelemetry/doc.go

@@ -15,33 +15,28 @@
 //
 // 2. configtelemetry.Basic
 //
-// Telemetry associated with this level provides essential coverage of the collector telemetry.
-// It should only be used for internal collector telemetry generated by the collector core API. Components outside of
-// the core API MUST NOT record additional telemetry at this level.
+// Telemetry associated with this level provides essential coverage of the Collector telemetry.
+// It should only be used for telemetry generated by the core Collector API.
+// Components outside of the core API MUST NOT record telemetry at this level.
 //
 // 3. configtelemetry.Normal
 //
-// Telemetry associated with this level provides complete coverage of the collector telemetry.
+// Telemetry associated with this level provides intermediate coverage of the Collector telemetry.
 // It should be the default for component authors.
 //
-// Component authors using this telemetry level can use this guidance:
-//
-//   - The signals associated with this level must control cardinality.
-//     It is acceptable at this level for cardinality to scale linearly with the monitored resources.
-//
-//   - The signals associated with this level must represent a controlled data volume. Examples follow:
+// Normal-level telemetry should have limited cardinality and data volume, though it is acceptable
+// for them to scale linearly with the monitored resources.
+// For example, there may be a limit of 5 attribute sets or 5 spans generated per request.
 //
-//     a. A max cardinality (total possible combinations of dimension values) for a given metric of at most 100.
-//
-//     b. At most 5 spans actively recording simultaneously per active request.
+// Normal-level telemetry should also have a low computational cost: it should not contain values
+// requiring significant additional computation compared to the normal flow of processing.
 //
 // This is the default level recommended when running the Collector.
 //
 // 4. configtelemetry.Detailed
 //
 // Telemetry associated with this level provides complete coverage of the collector telemetry.
 //
-// The signals associated with this level may exhibit high cardinality and/or high dimensionality.
-//
-// There is no limit on data volume.
+// The signals associated with this level may exhibit high cardinality, high data volume, or high
+// computational cost.
 package configtelemetry // import "go.opentelemetry.io/collector/config/configtelemetry"

docs/component-stability.md

@@ -214,6 +214,9 @@ If data can be dropped/created/held at multiple distinct points in a component's
 scraping, validation, processing, etc.), it is recommended to define additional attributes to help
 diagnose the specific source of the discrepancy, or to define different signals for each.
 
+The breakdown of emitted telemetry per telemetry level (basic / normal / detailed) should follow
+the guidelines in [the Go package documentation for `configtelemetry`](config/configtelemetry/doc.go).
+
 ### Deprecated
 
 The component is planned to be removed in a future version and no further support will be provided. Note that new issues will likely not be worked on. When a component enters "deprecated" mode, it is expected to exist for at least two minor releases. See the component's readme file for more details on when a component will cease to exist.

service/service.go

@@ -509,8 +509,12 @@ func configureViews(level configtelemetry.Level) []config.View {
 	}
 
 	// Batch processor metrics
-	if level < configtelemetry.LevelDetailed {
-		scope := ptr("go.opentelemetry.io/collector/processor/batchprocessor")
+	scope := ptr("go.opentelemetry.io/collector/processor/batchprocessor")
+	if level < configtelemetry.LevelNormal {
+		views = append(views, dropViewOption(&config.ViewSelector{
+			MeterName: scope,
+		}))
+	} else if level < configtelemetry.LevelDetailed {
 		views = append(views, dropViewOption(&config.ViewSelector{
 			MeterName:      scope,
 			InstrumentName: ptr("otelcol_processor_batch_batch_send_size_bytes"),