Add telemetry for metrics_ingestion_path & json_endpoint_used.

Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>

CHANGELOG.md

@@ -13,6 +13,11 @@ We use the following categories for changes:
 - `Fixed` for any bug fixes.
 - `Security` in case of vulnerabilities.
 
+## Unreleased
+
+### Added
+- Telemetry for `promscale_metrics_ingestion_path` and `promscale_metrics_ingestion_json_endpoint_used` [#1695]
+
 ## [0.15.0] - 2022-10-11
 
 ### Added

pkg/api/parser/parser.go

@@ -9,6 +9,7 @@ import (
 	"github.com/timescale/promscale/pkg/api/parser/protobuf"
 	"github.com/timescale/promscale/pkg/api/parser/text"
 	"github.com/timescale/promscale/pkg/prompb"
+	"github.com/timescale/promscale/pkg/telemetry"
 )
 
 type formatParser func(*http.Request, *prompb.WriteRequest) error
@@ -62,6 +63,8 @@ func (d DefaultParser) ParseRequest(r *http.Request, req *prompb.WriteRequest) e
 		return fmt.Errorf("parser error: %w", err)
 	}
 
+	updateTelemetry(mediaType)
+
 	if len(req.Timeseries) == 0 {
 		return nil
 	}
@@ -81,3 +84,24 @@ func (d DefaultParser) ParseRequest(r *http.Request, req *prompb.WriteRequest) e
 
 	return nil
 }
+
+func InitTelemetry() {
+	telemetry.Registry.Update("metrics_ingestion_path", "no_ingestion")
+	telemetry.Registry.Update("metrics_ingestion_json_endpoint_used", "0")
+}
+
+func updateTelemetry(parser string) {
+	switch parser {
+	case "application/x-protobuf":
+		telemetry.Registry.Update("metrics_ingestion_path", "protobuf")
+	case "application/json":
+		telemetry.Registry.Update("metrics_ingestion_path", "json")
+		telemetry.Registry.Update("metrics_ingestion_json_endpoint_used", "1")
+	case "text/plain":
+		telemetry.Registry.Update("metrics_ingestion_path", "text_plain")
+	case "application/openmetrics-text":
+		telemetry.Registry.Update("metrics_ingestion_path", "text_open_metrics")
+	default:
+		telemetry.Registry.Update("metrics_ingestion_path", "none")
+	}
+}

pkg/rules/rules.go

@@ -24,34 +24,8 @@ import (
 	"github.com/timescale/promscale/pkg/pgclient"
 	"github.com/timescale/promscale/pkg/rules/adapters"
 	"github.com/timescale/promscale/pkg/telemetry"
-	"github.com/timescale/promscale/pkg/util"
 )
 
-var (
-	// These metrics are used to track telemetry by registering
-	// in telemetryEngine.RegisterDynamicMetadata()
-	rulesEnabled = prometheus.NewGauge(
-		prometheus.GaugeOpts{
-			Namespace: util.PromNamespace,
-			Subsystem: "rules",
-			Name:      "enabled",
-			Help:      "Promscale rules is enabled or not.",
-		},
-	)
-	alertingEnabled = prometheus.NewGauge(
-		prometheus.GaugeOpts{
-			Namespace: util.PromNamespace,
-			Subsystem: "alerting",
-			Name:      "enabled",
-			Help:      "Promscale alerting is enabled or not.",
-		},
-	)
-)
-
-func init() {
-	prometheus.MustRegister(rulesEnabled, alertingEnabled)
-}
-
 type Manager struct {
 	ctx                 context.Context
 	rulesManager        *prom_rules.Manager
@@ -98,14 +72,9 @@ func NewManager(ctx context.Context, r prometheus.Registerer, client *pgclient.C
 	return manager, manager.getReloader(cfg), nil
 }
 
-func RegisterForTelemetry(t telemetry.Engine) error {
-	if err := t.RegisterDynamicMetadata("rules_enabled", rulesEnabled); err != nil {
-		return fmt.Errorf("register dynamic 'promscale_rules_enabled' metric for telemetry: %w", err)
-	}
-	if err := t.RegisterDynamicMetadata("alerting_enabled", alertingEnabled); err != nil {
-		return fmt.Errorf("register dynamic 'promscale_alerting_enabled' metric for telemetry: %w", err)
-	}
-	return nil
+func InitTelemetry() {
+	telemetry.Registry.Update("rules_enabled", "0")
+	telemetry.Registry.Update("alerting_enabled", "0")
 }
 
 func (m *Manager) getReloader(cfg *Config) func() error {
@@ -124,17 +93,17 @@ func (m *Manager) getReloader(cfg *Config) func() error {
 
 func (m *Manager) updateTelemetry(cfg *Config) {
 	if cfg.ContainsRules() {
-		rulesEnabled.Set(1)
+		telemetry.Registry.Update("rules_enabled", "1")
 		if cfg.ContainsAlertingConfig() {
-			alertingEnabled.Set(1)
+			telemetry.Registry.Update("alerting_enabled", "1")
 		} else {
 			log.Debug("msg", "Alerting configuration not present in the given Prometheus configuration file. Alerting will not be initialized")
-			alertingEnabled.Set(0)
+			telemetry.Registry.Update("alerting_enabled", "0")
 		}
 		return
 	}
 	log.Debug("msg", "Rules files not found. Rules and alerting configuration will not be initialized")
-	rulesEnabled.Set(0)
+	telemetry.Registry.Update("rules_enabled", "0")
 }
 
 func (m *Manager) WithPostRulesProcess(f prom_rules.RuleGroupPostProcessFunc) {

pkg/runner/runner.go

@@ -35,6 +35,7 @@ import (
 	"github.com/thanos-io/thanos/pkg/store/storepb"
 
 	"github.com/timescale/promscale/pkg/api"
+	"github.com/timescale/promscale/pkg/api/parser"
 	jaegerStore "github.com/timescale/promscale/pkg/jaeger/store"
 	"github.com/timescale/promscale/pkg/log"
 	"github.com/timescale/promscale/pkg/pgclient"
@@ -368,8 +369,7 @@ func initTelemetryEngine(client *pgclient.Client) (telemetry.Engine, error) {
 	if err := trace.RegisterTelemetryMetrics(t); err != nil {
 		log.Error("msg", "error registering metrics for Jaeger-ingest telemetry", "err", err.Error())
 	}
-	if err := rules.RegisterForTelemetry(t); err != nil {
-		log.Error("msg", "error registering metrics for rules telemetry", "err", err.Error())
-	}
+	parser.InitTelemetry()
+	rules.InitTelemetry()
 	return t, nil
 }

pkg/telemetry/registry.go

@@ -0,0 +1,27 @@
+// This file and its contents are licensed under the Apache License 2.0.
+// Please see the included NOTICE for copyright information and
+// LICENSE for a copy of the license.
+
+package telemetry
+
+import "sync"
+
+type reg struct {
+	r sync.Map
+}
+
+func (r *reg) Update(telemetryName, value string) {
+	r.r.Store(telemetryName, value)
+}
+
+func (r *reg) metadata() (m Metadata) {
+	m = Metadata{}
+	r.r.Range(func(telemetryName, value interface{}) bool {
+		m[telemetryName.(string)] = value.(string)
+		return true
+	})
+	return m
+}
+
+// Registry is a telemetry holder that is mutable and can be filled from anywhere in Promscale.
+var Registry reg

pkg/telemetry/telemetry.go

@@ -30,12 +30,8 @@ var ErrInvalidMetric = fmt.Errorf("metric not a counter or gauge")
 // the _timescaledb_catalog.metadata table.
 type Engine interface {
 	// RegisterMetric registers a Prometheus metric with a column name. This metric is
-	// monitored every telemetrySync and updated in the telemetry table.
+	// monitored every telemetrySync and updated in the promscale_instance_information table.
 	RegisterMetric(columnName string, gaugeOrCounterMetric ...prometheus.Metric) error
-
-	// RegisterDynamicMetadata is a Prometheus metric that changes regularly. This is monitored
-	// every telemetrySync and updated in the telemetry table.
-	RegisterDynamicMetadata(columnName string, gauge prometheus.Metric) error
 	Start()
 	Stop()
 }
@@ -120,56 +116,19 @@ func (t *engineImpl) writeToTimescaleMetadataTable(m Metadata) {
 		return
 	}
 	// Try to update via Promscale extension.
-	if err := t.syncWithMetadataTable(metadataUpdateWithExtension, m); err != nil {
+	if err := syncWithMetadataTable(t.conn, metadataUpdateWithExtension, m); err != nil {
 		// Promscale extension not installed. Try to attempt to write directly as a rare attempt
 		// in case we fix the _timescaledb_catalog.metadata permissions in the future.
-		_ = t.syncWithMetadataTable(metadataUpdateNoExtension, m)
+		_ = syncWithMetadataTable(t.conn, metadataUpdateNoExtension, m)
 	}
 }
 
-func (t *engineImpl) RegisterDynamicMetadata(telemetryName string, gauge prometheus.Metric) error {
-	if !isGauge(gauge) {
-		return ErrInvalidMetric
-	}
-	t.dynamicMetadata.Store(telemetryName, gauge)
-	return nil
-}
-
-func (t *engineImpl) syncDynamicMetadata() error {
-	var (
-		err      error
-		val      float64
-		metadata = Metadata{}
-	)
-	t.dynamicMetadata.Range(func(key, value interface{}) bool {
-		columnName := key.(string)
-		metric := value.(prometheus.Metric)
-		val, err = util.ExtractMetricValue(metric)
-		if err != nil {
-			err = fmt.Errorf("extracting metric value of stat '%s': %w", columnName, err)
-			return false
-		}
-		var state string
-		switch val {
-		case 0:
-			state = "false"
-		case 1:
-			state = "true"
-		default:
-			err = fmt.Errorf("invalid state value '%f' for stat '%s'", val, columnName)
-		}
-		metadata[columnName] = state
-		return true
-	})
-	if err != nil {
-		return err
-	}
-	t.writeToTimescaleMetadataTable(metadata)
-	return nil
+func (t *engineImpl) syncRegistry() {
+	t.writeToTimescaleMetadataTable(Registry.metadata())
 }
 
-func (t *engineImpl) syncWithMetadataTable(queryFormat string, m Metadata) error {
-	batch := t.conn.NewBatch()
+func syncWithMetadataTable(conn pgxconn.PgxConn, queryFormat string, m Metadata) error {
+	batch := conn.NewBatch()
 	for key, metadata := range m {
 		safe := pgutf8str.Text{}
 		if err := safe.Set(metadata); err != nil {
@@ -179,7 +138,7 @@ func (t *engineImpl) syncWithMetadataTable(queryFormat string, m Metadata) error
 		batch.Queue(query, key, safe, true)
 	}
 
-	results, err := t.conn.SendBatch(context.Background(), batch)
+	results, err := conn.SendBatch(context.Background(), batch)
 	if err != nil {
 		return fmt.Errorf("error sending batch: %w", err)
 	}
@@ -209,9 +168,7 @@ func (t *engineImpl) Sync() error {
 	if err := t.syncWithInfoTable(); err != nil {
 		return fmt.Errorf("sync info table: %w", err)
 	}
-	if err := t.syncDynamicMetadata(); err != nil {
-		return fmt.Errorf("sync dynamic metadata: %w", err)
-	}
+	t.syncRegistry()
 	t.housekeeping()
 	return nil
 }
@@ -291,6 +248,10 @@ func (t *engineImpl) RegisterMetric(columnName string, gaugeOrCounterMetrics ...
 	return nil
 }
 
+func (t *engineImpl) WriteOnce(telemetryName, value string) {
+	t.writeToTimescaleMetadataTable(Metadata{telemetryName: value})
+}
+
 func isCounterOrGauge(metric prometheus.Metric) bool {
 	switch metric.(type) {
 	case prometheus.Counter, prometheus.Gauge: