fix: make data syncer run configurable on mode (2->3) change (#104401)

go.mod

@@ -455,7 +455,7 @@ require (
 	github.com/mithrandie/ternary v1.1.1 // indirect
 	github.com/moby/spdystream v0.5.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
-	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
+	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect	
 	github.com/mschoch/smat v0.2.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f // indirect

pkg/apiserver/rest/dualwriter.go

@@ -164,6 +164,10 @@ func SetDualWritingMode(
 			return Mode0, errDualWriterSetCurrentMode
 		}
 	case cfg.Mode >= Mode3 && currentMode < Mode3:
+		if cfg.SkipDataSync {
+			return currentMode, nil
+		}
+
 		// Transitioning to Mode3 or higher requires data synchronization.
 		cfgModeTmp := cfg.Mode
 		// Before running the sync, set the syncer config to the current mode, as we have to run the syncer

pkg/apiserver/rest/dualwriter_syncer.go

@@ -36,6 +36,7 @@ type SyncerConfig struct {
 	LegacyStorage     Storage
 	Storage           Storage
 	ServerLockService ServerLockService
+	SkipDataSync      bool
 
 	DataSyncerInterval     time.Duration
 	DataSyncerRecordsLimit int

pkg/apiserver/rest/dualwriter_test.go

@@ -20,6 +20,7 @@ func TestSetDualWritingMode(t *testing.T) {
 		kvStore         *fakeNamespacedKV
 		desiredMode     DualWriterMode
 		expectedMode    DualWriterMode
+		skipDataSync    bool
 		serverLockError error
 	}
 	tests :=
@@ -61,6 +62,13 @@ func TestSetDualWritingMode(t *testing.T) {
 				expectedMode:    Mode2,
 				serverLockError: fmt.Errorf("lock already exists"),
 			},
+			{
+				name:         "should keep mode2 when trying to go from mode2 to mode3 and migration is disabled",
+				kvStore:      &fakeNamespacedKV{data: map[string]string{"playlist.grafana.app/playlists": "2"}, namespace: "storage.dualwriting"},
+				desiredMode:  Mode3,
+				expectedMode: Mode2,
+				skipDataSync: true,
+			},
 		}
 
 	for _, tt := range tests {
@@ -86,6 +94,7 @@ func TestSetDualWritingMode(t *testing.T) {
 			Storage:           us,
 			Kind:              "playlist.grafana.app/playlists",
 			Mode:              tt.desiredMode,
+			SkipDataSync:      tt.skipDataSync,
 			ServerLockService: serverLockSvc,
 			RequestInfo:       &request.RequestInfo{},
 			Reg:               p,

pkg/services/apiserver/builder/helper.go

@@ -315,6 +315,7 @@ func InstallAPIs(
 
 			var (
 				dualWriterPeriodicDataSyncJobEnabled bool
+				dualWriterMigrationDataSyncDisabled  bool
 				dataSyncerInterval                   = time.Hour
 				dataSyncerRecordsLimit               = 1000
 			)
@@ -323,6 +324,7 @@ func InstallAPIs(
 			if resourceExists {
 				mode = resourceConfig.DualWriterMode
 				dualWriterPeriodicDataSyncJobEnabled = resourceConfig.DualWriterPeriodicDataSyncJobEnabled
+				dualWriterMigrationDataSyncDisabled = resourceConfig.DualWriterMigrationDataSyncDisabled
 				dataSyncerInterval = resourceConfig.DataSyncerInterval
 				dataSyncerRecordsLimit = resourceConfig.DataSyncerRecordsLimit
 			}
@@ -343,6 +345,7 @@ func InstallAPIs(
 				Kind:                   key,
 				RequestInfo:            requestInfo,
 				Mode:                   mode,
+				SkipDataSync:           dualWriterMigrationDataSyncDisabled,
 				LegacyStorage:          legacy,
 				Storage:                storage,
 				ServerLockService:      serverLock,

pkg/setting/setting.go

@@ -556,6 +556,7 @@ type Cfg struct {
 type UnifiedStorageConfig struct {
 	DualWriterMode                       rest.DualWriterMode
 	DualWriterPeriodicDataSyncJobEnabled bool
+	DualWriterMigrationDataSyncDisabled  bool
 	// DataSyncerInterval defines how often the data syncer should run for a resource on the grafana instance.
 	DataSyncerInterval time.Duration
 	// DataSyncerRecordsLimit defines how many records will be processed at max during a sync invocation.

pkg/setting/setting_unified_storage.go

@@ -30,6 +30,9 @@ func (cfg *Cfg) setUnifiedStorageConfig() {
 		// parse dualWriter periodic data syncer config
 		dualWriterPeriodicDataSyncJobEnabled := section.Key("dualWriterPeriodicDataSyncJobEnabled").MustBool(false)
 
+		// parse dualWriter migration data sync disabled from resource section
+		dualWriterMigrationDataSyncDisabled := section.Key("dualWriterMigrationDataSyncDisabled").MustBool(false)
+
 		// parse dataSyncerRecordsLimit from resource section
 		dataSyncerRecordsLimit := section.Key("dataSyncerRecordsLimit").MustInt(1000)
 
@@ -39,6 +42,7 @@ func (cfg *Cfg) setUnifiedStorageConfig() {
 		storageConfig[resourceName] = UnifiedStorageConfig{
 			DualWriterMode:                       rest.DualWriterMode(dualWriterMode),
 			DualWriterPeriodicDataSyncJobEnabled: dualWriterPeriodicDataSyncJobEnabled,
+			DualWriterMigrationDataSyncDisabled:  dualWriterMigrationDataSyncDisabled,
 			DataSyncerRecordsLimit:               dataSyncerRecordsLimit,
 			DataSyncerInterval:                   dataSyncerInterval,
 		}