Performance optimization for live debugging feature (#2294)

* Performance optimization for live debugging feature

* Moving the config to the livedebugging block

Remove config from docs

* Fix test cases

* Remove the config changes

CHANGELOG.md

@@ -52,6 +52,7 @@ Main (unreleased)
 - Add three new stdlib functions to_base64, from_URLbase64 and to_URLbase64 (@ravishankar15)
 - Add `ignore_older_than` option for local.file_match (@ravishankar15)
 - Add livedebugging support for `discover.relabel` (@ravishankar15)
+- Performance optimization for live debugging feature (@ravishankar15)
 
 - Upgrade `github.com/goccy/go-json` to v0.10.4, which reduces the memory consumption of an Alloy instance by 20MB.
   If Alloy is running certain otelcol components, this reduction will not apply. (@ptodev)

docs/sources/reference/config-blocks/livedebugging.md

@@ -30,8 +30,8 @@ livedebugging {
 
 The following arguments are supported:
 
-| Name      | Type   | Description                         | Default | Required |
-| --------- | ------ | ----------------------------------- | ------- | -------- |
-| `enabled` | `bool` | Enables the live debugging feature. | `false` | no       |
+| Name                 | Type  | Description                                                      | Default | Required |
+| -------------------- | ----- | ---------------------------------------------------------------  | ------- | -------- |
+| `enabled`            | `bool`| Enables the live debugging feature.                              | `false` | no       |
 
 [debug]: ../../../troubleshoot/debug/

internal/component/loki/process/process_test.go

@@ -53,7 +53,7 @@ func TestJSONLabelsStage(t *testing.T) {
 	// The third stage will set some labels from the extracted values above.
 	// Again, if the value is empty, it is inferred that we want to use the
 	// populate the label with extracted value of the same name.
-	stg := `stage.json { 
+	stg := `stage.json {
 			    expressions    = {"output" = "log", stream = "stream", timestamp = "time", "extra" = "" }
 				drop_malformed = true
 		    }
@@ -62,7 +62,7 @@ func TestJSONLabelsStage(t *testing.T) {
 				source      = "extra"
 			}
 			stage.labels {
-			    values = { 
+			    values = {
 				  stream = "",
 				  user   = "",
 				  ts     = "timestamp",
@@ -679,7 +679,7 @@ func TestLeakyUpdate(t *testing.T) {
 	numLogsToSend := 1
 
 	cfg1 := `
-	stage.metrics { 
+	stage.metrics {
         metric.counter {
           name = "paulin_test1"
           action = "inc"
@@ -688,7 +688,7 @@ func TestLeakyUpdate(t *testing.T) {
 	}` + forwardArgs
 
 	cfg2 := `
-	stage.metrics { 
+	stage.metrics {
         metric.counter {
           name = "paulin_test2"
           action = "inc"
@@ -731,7 +731,7 @@ func TestMetricsStageRefresh(t *testing.T) {
 	numLogsToSend := 3
 
 	cfgWithMetric := `
-	stage.metrics { 
+	stage.metrics {
         metric.counter {
           name = "paulin_test"
           action = "inc"
@@ -776,7 +776,7 @@ func TestMetricsStageRefresh(t *testing.T) {
 	// We try having a metric with the same name as before so that we can see if there
 	// is some sort of double registration error for that metric.
 	cfgWithTwoMetrics := `
-	stage.metrics { 
+	stage.metrics {
 		metric.counter {
 		  name = "paulin_test_3"
 		  action = "inc"

internal/web/api/api.go

@@ -11,6 +11,7 @@ import (
 	"path"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/google/uuid"
 	"github.com/gorilla/mux"
@@ -165,13 +166,11 @@ func getClusteringPeersHandler(host service.Host) http.HandlerFunc {
 	}
 }
 
-func liveDebugging(host service.Host, callbackManager livedebugging.CallbackManager) http.HandlerFunc {
+func liveDebugging(_ service.Host, callbackManager livedebugging.CallbackManager) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		vars := mux.Vars(r)
 		componentID := livedebugging.ComponentID(vars["id"])
 
-		// Buffer of 1000 entries to handle load spikes and prevent this functionality from eating up too much memory.
-		// TODO: in the future we may want to make this value configurable to handle heavy load
 		dataCh := make(chan string, 1000)
 		ctx := r.Context()
 
@@ -200,9 +199,12 @@ func liveDebugging(host service.Host, callbackManager livedebugging.CallbackMana
 			return
 		}
 
+		flushTicker := time.NewTicker(time.Second)
+
 		defer func() {
 			close(dataCh)
 			callbackManager.DeleteCallback(id, componentID)
+			flushTicker.Stop()
 		}()
 
 		for {
@@ -216,7 +218,7 @@ func liveDebugging(host service.Host, callbackManager livedebugging.CallbackMana
 				if writeErr != nil {
 					return
 				}
-				// TODO: flushing at a regular interval might be better performance wise
+			case <-flushTicker.C:
 				w.(http.Flusher).Flush()
 			case <-ctx.Done():
 				return