Introduce TSDB service (#31520)

* Introduce TSDB service

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Co-authored-by: Erik Sundell <erik.sundell87@gmail.com>
Co-authored-by: Will Browne <will.browne@grafana.com>
Co-authored-by: Torkel Ödegaard <torkel@grafana.org>
Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>
Co-authored-by: Zoltán Bedi <zoltan.bedi@gmail.com>

pkg/plugins/backendplugin/instrumentation/instrumentation.go

@@ -0,0 +1,86 @@
+// Package instrumentation contains backend plugin instrumentation logic.
+package instrumentation
+
+import (
+	"context"
+	"time"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	pluginRequestCounter  *prometheus.CounterVec
+	pluginRequestDuration *prometheus.SummaryVec
+)
+
+func init() {
+	pluginRequestCounter = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "grafana",
+		Name:      "plugin_request_total",
+		Help:      "The total amount of plugin requests",
+	}, []string{"plugin_id", "endpoint", "status"})
+
+	pluginRequestDuration = prometheus.NewSummaryVec(prometheus.SummaryOpts{
+		Namespace:  "grafana",
+		Name:       "plugin_request_duration_milliseconds",
+		Help:       "Plugin request duration",
+		Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+	}, []string{"plugin_id", "endpoint"})
+
+	prometheus.MustRegister(pluginRequestCounter, pluginRequestDuration)
+}
+
+// instrumentPluginRequest instruments success rate and latency of `fn`
+func instrumentPluginRequest(pluginID string, endpoint string, fn func() error) error {
+	status := "ok"
+
+	start := time.Now()
+
+	err := fn()
+	if err != nil {
+		status = "error"
+	}
+
+	elapsed := time.Since(start) / time.Millisecond
+	pluginRequestDuration.WithLabelValues(pluginID, endpoint).Observe(float64(elapsed))
+	pluginRequestCounter.WithLabelValues(pluginID, endpoint, status).Inc()
+
+	return err
+}
+
+// InstrumentCollectMetrics instruments collectMetrics.
+func InstrumentCollectMetrics(pluginID string, fn func() error) error {
+	return instrumentPluginRequest(pluginID, "collectMetrics", fn)
+}
+
+// InstrumentCheckHealthRequest instruments checkHealth.
+func InstrumentCheckHealthRequest(pluginID string, fn func() error) error {
+	return instrumentPluginRequest(pluginID, "checkHealth", fn)
+}
+
+// InstrumentCallResourceRequest instruments callResource.
+func InstrumentCallResourceRequest(pluginID string, fn func() error) error {
+	return instrumentPluginRequest(pluginID, "callResource", fn)
+}
+
+// InstrumentQueryDataRequest instruments success rate and latency of query data requests.
+func InstrumentQueryDataRequest(pluginID string, fn func() error) error {
+	return instrumentPluginRequest(pluginID, "queryData", fn)
+}
+
+// InstrumentQueryDataHandler wraps a backend.QueryDataHandler with instrumentation of success rate and latency.
+func InstrumentQueryDataHandler(handler backend.QueryDataHandler) backend.QueryDataHandler {
+	if handler == nil {
+		return nil
+	}
+
+	return backend.QueryDataHandlerFunc(func(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
+		var resp *backend.QueryDataResponse
+		err := InstrumentQueryDataRequest(req.PluginContext.PluginID, func() (innerErr error) {
+			resp, innerErr = handler.QueryData(ctx, req)
+			return
+		})
+		return resp, err
+	})
+}