Added OTEL DB stats metrics, renamed trace attributes to expected OTEL names (#42097)

1. Added DB metrics via otelsql.RegisterDBStatsMetrics()
`db.sql.connection.open`
`db.sql.connection.max_open`
`db.sql.connection.wait`
`db.sql.connection.wait_duration`
`db.sql.connection.closed_max_idle`
`db.sql.connection.closed_max_idle_time`
`db.sql.latency.*`
2. renamed these metrics to signoz convention/expected names
`db.sql.connection.open` -> `db.client.connection.usage`
`db.sql.connection.max_open` -> `db.client.connection.max`
`db.sql.connection.wait` -> `db.client.connection.wait_count`
`db.sql.connection.wait_duration` -> `db.client.connection.wait_time`
`db.sql.connection.closed_max_idle` -> `db.client.connection.idle.max`
`db.sql.connection.closed_max_idle_time` ->
`db.client.connection.idle.min`
3. created custom dashboard to display these metrics, (import via json)
<img width="1580" height="906" alt="Screenshot 2026-03-19 at 2 44 43 PM"
src="https://github.com/user-attachments/assets/f1b64ed6-e534-4490-8955-bc1205dd21d4"
/>
4. Fixed metrics for service db dashboards
Signoz expects

`db.system` : Identifies the database type (e.g., postgresql, mysql,
mongodb).
`db.statement` : The actual query being executed (e.g., SELECT * FROM
users).
`db.operation` : The type of operation (e.g., SELECT, INSERT).
`service.name` : The name of the service making the call.

We needed to set the `db.system` attribute explicitly.

`db.operation` is missing because otelsql doesn't capture this by
default. Decided not to add this for now as the dashboards work without.
Can be a future enhancement.

<img width="1563" height="487" alt="Screenshot 2026-03-19 at 2 45 18 PM"
src="https://github.com/user-attachments/assets/51028e16-ee2c-45a9-9025-26f17b0db67a"
/>


# Checklist for submitter

## Testing
- [x] QA'd all new/changed functionality manually

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

## Release Notes

* **New Features**
* Added a new observability dashboard for database and connection
performance metrics, including RPS, latency, connection pool saturation,
and queue statistics.
* Enhanced database metrics collection with automatic registration of
connection and query performance indicators.
* Standardized OpenTelemetry metric naming to align with industry
conventions for improved observability compatibility.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

cmd/fleet/serve.go

@@ -228,9 +228,40 @@ func runServeCmd(cmd *cobra.Command, configManager configpkg.Manager, debug, dev
 		if err != nil {
 			initFatal(err, "Failed to initialize OTEL metrics exporter")
 		}
+
+		// Create views to rename otelsql metrics to match what OpenTelemetry Signoz expects
+		// Reference: https://opentelemetry.io/docs/specs/semconv/db/database-metrics/
+		dbMetricViews := []sdkmetric.View{
+			sdkmetric.NewView(
+				sdkmetric.Instrument{Name: "db.sql.connection.open"},
+				sdkmetric.Stream{Name: "db.client.connection.count"},
+			),
+			sdkmetric.NewView(
+				sdkmetric.Instrument{Name: "db.sql.connection.max_open"},
+				sdkmetric.Stream{Name: "db.client.connection.max"},
+			),
+			sdkmetric.NewView(
+				sdkmetric.Instrument{Name: "db.sql.connection.wait"},
+				sdkmetric.Stream{Name: "db.client.connection.wait_count"},
+			),
+			sdkmetric.NewView(
+				sdkmetric.Instrument{Name: "db.sql.connection.wait_duration"},
+				sdkmetric.Stream{Name: "db.client.connection.wait_time"},
+			),
+			sdkmetric.NewView(
+				sdkmetric.Instrument{Name: "db.sql.connection.closed_max_idle"},
+				sdkmetric.Stream{Name: "db.client.connection.closed.max_idle"},
+			),
+			sdkmetric.NewView(
+				sdkmetric.Instrument{Name: "db.sql.connection.closed_max_idle_time"},
+				sdkmetric.Stream{Name: "db.client.connection.closed.max_idle_time"},
+			),
+		}
+
 		meterProvider = sdkmetric.NewMeterProvider(
 			sdkmetric.WithResource(res),
 			sdkmetric.WithReader(sdkmetric.NewPeriodicReader(metricExporter)),
+			sdkmetric.WithView(dbMetricViews...),
 		)
 		otel.SetMeterProvider(meterProvider)
 

server/datastore/mysql/mysql.go

@@ -35,6 +35,7 @@ import (
 	"github.com/go-sql-driver/mysql"
 	"github.com/hashicorp/go-multierror"
 	"github.com/jmoiron/sqlx"
+	"go.opentelemetry.io/otel/attribute"
 	semconv "go.opentelemetry.io/otel/semconv/v1.39.0"
 )
 
@@ -342,7 +343,10 @@ var otelTracedDriverName string
 func init() {
 	var err error
 	otelTracedDriverName, err = otelsql.Register("mysql",
-		otelsql.WithAttributes(semconv.DBSystemNameMySQL),
+		otelsql.WithAttributes(
+			attribute.String("db.system", "mysql"),
+			semconv.DBSystemNameMySQL,
+		),
 		otelsql.WithSpanOptions(otelsql.SpanOptions{
 			// DisableErrSkip ignores driver.ErrSkip errors which are frequently returned by the MySQL driver
 			// when certain optional methods or paths are not implemented/taken.

server/platform/mysql/common.go

@@ -9,10 +9,12 @@ import (
 	"net/url"
 	"time"
 
+	"github.com/XSAM/otelsql"
 	"github.com/fleetdm/fleet/v4/server/contexts/ctxerr"
 	"github.com/go-sql-driver/mysql"
 	"github.com/jmoiron/sqlx"
 	"github.com/ngrok/sqlmw"
+	"go.opentelemetry.io/otel/attribute"
 )
 
 // ConnectorFactory creates a driver.Connector for custom database authentication.
@@ -114,6 +116,26 @@ func NewDB(conf *MysqlConfig, opts *DBOptions, otelDriverName string) (*sqlx.DB,
 	if dbError != nil {
 		return nil, dbError
 	}
+
+	// Register database/sql.DBStats metrics when using OpenTelemetry tracing.
+	if opts.TracingConfig != nil && opts.TracingConfig.TracingEnabled && opts.TracingConfig.TracingType != "elasticapm" {
+		attrs := []attribute.KeyValue{
+			attribute.String("db.system", "mysql"),
+		}
+		// Parse DSN to extract address and database name for metric differentiation
+		if cfg, err := mysql.ParseDSN(dsn); err == nil {
+			if cfg.Addr != "" {
+				attrs = append(attrs, attribute.String("db.addr", cfg.Addr))
+			}
+			if cfg.DBName != "" {
+				attrs = append(attrs, attribute.String("db.name", cfg.DBName))
+			}
+		}
+		if err := otelsql.RegisterDBStatsMetrics(db.DB, otelsql.WithAttributes(attrs...)); err != nil {
+			opts.Logger.WarnContext(context.Background(), "failed to register DB stats metrics", "err", err)
+		}
+	}
+
 	return db, nil
 }