Merge pull request #7810 from TheThingsNetwork/feat/as-redis-list-watch-update

Backport of Redis webhook List operations

Author: nicholaspcr

CHANGELOG.md

@@ -30,6 +30,10 @@ For details about compatibility between different releases, see the **Commitment
 - Add HSTS response headers.
 - Draft band definition for Uzbekistan 923Mhz band.
 
+### Fixed
+
+- Application Server webhook registry now uses read-only Redis client for non-paginated list operations, reducing connection holding time during high traffic.
+
 ## [3.35.1] - 2025-12-19
 
 ## [3.35.0] - 2025-11-19

pkg/applicationserver/io/web/redis/registry.go

@@ -102,16 +102,19 @@ func (r WebhookRegistry) List(ctx context.Context, ids *ttnpb.ApplicationIdentif
 	appUID := unique.ID(ctx, ids)
 	uidKey := r.appKey(appUID)
 
-	opts := []ttnredis.FindProtosOption{}
+	defer trace.StartRegion(ctx, "list webhooks by application id").End()
+
 	limit, offset := ttnredis.PaginationLimitAndOffsetFromContext(ctx)
-	if limit != 0 {
-		opts = append(opts,
-			ttnredis.FindProtosSorted(true),
-			ttnredis.FindProtosWithOffsetAndCount(offset, limit),
-		)
-	}
 
 	rangeProtos := func(c redis.Cmdable) error {
+		var opts []ttnredis.FindProtosOption
+		if limit != 0 {
+			opts = append(opts,
+				ttnredis.FindProtosSorted(true),
+				ttnredis.FindProtosWithOffsetAndCount(offset, limit),
+			)
+		}
+		pbs = make([]*ttnpb.ApplicationWebhook, 0)
 		return ttnredis.FindProtos(ctx, c, uidKey, r.makeIDKeyFunc(appUID), opts...).Range(
 			func() (proto.Message, func() (bool, error)) {
 				pb := &ttnpb.ApplicationWebhook{}
@@ -126,27 +129,21 @@ func (r WebhookRegistry) List(ctx context.Context, ids *ttnpb.ApplicationIdentif
 			})
 	}
 
-	defer trace.StartRegion(ctx, "list webhooks by application id").End()
-
 	var err error
 	if limit != 0 {
-		var lockerID string
-		lockerID, err = ttnredis.GenerateLockerID()
-		if err != nil {
-			return nil, err
-		}
-		err = ttnredis.LockedWatch(ctx, r.Redis, uidKey, lockerID, r.LockTTL, func(tx *redis.Tx) (err error) {
+		// Pagination requires Watch() for consistency between SCard and SORT.
+		err = r.Redis.Watch(ctx, func(tx *redis.Tx) error {
 			total, err := tx.SCard(ctx, uidKey).Result()
 			if err != nil {
 				return err
 			}
 			ttnredis.SetPaginationTotal(ctx, total)
 			return rangeProtos(tx)
-		})
+		}, uidKey)
 	} else {
+		// No pagination - use client without Watch() to reduce connection holding time.
 		err = rangeProtos(r.Redis)
 	}
-
 	if err != nil {
 		return nil, ttnredis.ConvertError(err)
 	}

pkg/applicationserver/io/web/redis/registry_test.go

@@ -179,6 +179,42 @@ func TestWebhookRegistry(t *testing.T) {
 		a.So(webhooks[0].Format, should.Equal, format)
 	})
 
+	t.Run("ListMultipleWithoutPagination", func(t *testing.T) {
+		t.Parallel()
+		a, ctx := test.New(t)
+
+		appID := &ttnpb.ApplicationIdentifiers{
+			ApplicationId: "myapp-list-multiple",
+		}
+
+		// Create multiple webhooks
+		for i := 1; i <= 5; i++ {
+			whIDs := &ttnpb.ApplicationWebhookIdentifiers{
+				ApplicationIds: appID,
+				WebhookId:      fmt.Sprintf("webhook-%02d", i),
+			}
+			_, err := registry.Set(ctx, whIDs, paths,
+				func(*ttnpb.ApplicationWebhook) (*ttnpb.ApplicationWebhook, []string, error) {
+					return &ttnpb.ApplicationWebhook{
+						Ids:     whIDs,
+						Format:  format,
+						BaseUrl: baseURL,
+					}, paths, nil
+				},
+			)
+			a.So(err, should.BeNil)
+		}
+
+		// List without pagination context - exercises ReadOnlyClient() path
+		webhooks, err := registry.List(ctx, appID, paths)
+		a.So(err, should.BeNil)
+		a.So(webhooks, should.HaveLength, 5)
+		for _, wh := range webhooks {
+			a.So(wh.Ids.ApplicationIds, should.Resemble, appID)
+			a.So(wh.Format, should.Equal, format)
+		}
+	})
+
 	t.Run("Pagination", func(t *testing.T) {
 		t.Parallel()
 		a, ctx := test.New(t)