Do not refresh the snapshot on frozen containers.

packages/loader/container-loader/src/container.ts

@@ -1021,12 +1021,17 @@ export class Container
 			(this.isInteractiveClient &&
 				this.mc.config.getBoolean("Fluid.Container.enableOfflineLoad")) ??
 			options.enableOfflineLoad === true;
+		let storageOnly = false;
+		if (this.readOnlyInfo.readonly === true) {
+			storageOnly = this.readOnlyInfo.storageOnly;
+		}
 		this.serializedStateManager = new SerializedStateManager(
 			pendingLocalState,
 			this.subLogger,
 			this.storageAdapter,
 			offlineLoadEnabled,
 			this,
+			storageOnly,
 			() => this._deltaManager.connectionManager.shouldJoinWrite(),
 			() => this.supportGetSnapshotApi(),
 			this.mc.config.getNumber("Fluid.Container.snapshotRefreshTimeoutMs"),

packages/loader/container-loader/src/serializedStateManager.ts

@@ -149,7 +149,7 @@ export class SerializedStateManager {
 	private latestSnapshot: ISnapshotInfo | undefined;
 	private _refreshSnapshotP: Promise<number> | undefined;
 	private readonly lastSavedOpSequenceNumber: number = 0;
-	private readonly refreshTimer: Timer;
+	private readonly refreshTimer: Timer | undefined;
 	private readonly snapshotRefreshTimeoutMs: number = 60 * 60 * 24 * 1000;
 
 	/**
@@ -166,6 +166,7 @@ export class SerializedStateManager {
 		private readonly storageAdapter: ISerializedStateManagerDocumentStorageService,
 		private readonly _offlineLoadEnabled: boolean,
 		containerEvent: IEventProvider<ISerializerEvent>,
+		private readonly storageOnly: boolean,
 		private readonly containerDirty: () => boolean,
 		private readonly supportGetSnapshotApi: () => boolean,
 		snapshotRefreshTimeoutMs?: number,
@@ -176,9 +177,9 @@ export class SerializedStateManager {
 		});
 
 		this.snapshotRefreshTimeoutMs = snapshotRefreshTimeoutMs ?? this.snapshotRefreshTimeoutMs;
-		this.refreshTimer = new Timer(this.snapshotRefreshTimeoutMs, () =>
-			this.tryRefreshSnapshot(),
-		);
+		this.refreshTimer = this.storageOnly
+			? undefined
+			: new Timer(this.snapshotRefreshTimeoutMs, () => this.tryRefreshSnapshot());
 		// special case handle. Obtaining the last saved op seq num to avoid
 		// refreshing the snapshot before we have processed it. It could cause
 		// a subsequent stashing to have a newer snapshot than allowed.
@@ -244,7 +245,7 @@ export class SerializedStateManager {
 					snapshotBlobs,
 					snapshotSequenceNumber: attributes.sequenceNumber,
 				};
-				this.refreshTimer.start();
+				this.refreshTimer?.start();
 			}
 			return { baseSnapshot, version };
 		} else {
@@ -276,7 +277,8 @@ export class SerializedStateManager {
 		if (
 			this.mc.config.getBoolean("Fluid.Container.enableOfflineSnapshotRefresh") === true &&
 			this._refreshSnapshotP === undefined &&
-			this.latestSnapshot === undefined
+			this.latestSnapshot === undefined &&
+			!this.storageOnly
 		) {
 			// Don't block on the refresh snapshot call - it is for the next time we serialize, not booting this incarnation
 			this._refreshSnapshotP = this.refreshLatestSnapshot(this.supportGetSnapshotApi());
@@ -361,14 +363,14 @@ export class SerializedStateManager {
 				stashedSnapshotSequenceNumber: this.snapshot?.snapshotSequenceNumber,
 			});
 			this.latestSnapshot = undefined;
-			this.refreshTimer.restart();
+			this.refreshTimer?.restart();
 		} else if (snapshotSequenceNumber <= lastProcessedOpSequenceNumber) {
 			// Snapshot seq num is between the first and last processed op.
 			// Remove the ops that are already part of the snapshot
 			this.processedOps.splice(0, snapshotSequenceNumber - firstProcessedOpSequenceNumber + 1);
 			this.snapshot = this.latestSnapshot;
 			this.latestSnapshot = undefined;
-			this.refreshTimer.restart();
+			this.refreshTimer?.restart();
 			this.mc.logger.sendTelemetryEvent({
 				eventName: "SnapshotRefreshed",
 				snapshotSequenceNumber,
@@ -410,7 +412,7 @@ export class SerializedStateManager {
 				// eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
 				snapshotSequenceNumber: attributes.sequenceNumber as number,
 			};
-			this.refreshTimer.start();
+			this.refreshTimer?.start();
 		}
 	}
 

packages/loader/container-loader/src/test/serializedStateManager.spec.ts

@@ -191,6 +191,7 @@ describe("serializedStateManager", () => {
 				storageAdapter,
 				false,
 				eventEmitter,
+				false,
 				() => false,
 				() => false,
 			);
@@ -217,6 +218,7 @@ describe("serializedStateManager", () => {
 				}),
 				true,
 				eventEmitter,
+				false,
 				() => false,
 				() => false,
 			);
@@ -246,6 +248,7 @@ describe("serializedStateManager", () => {
 				storageAdapter,
 				true,
 				eventEmitter,
+				false,
 				() => false,
 				() => false,
 			);
@@ -269,6 +272,7 @@ describe("serializedStateManager", () => {
 				storageAdapter,
 				true,
 				eventEmitter,
+				false,
 				() => false,
 				() => false,
 			);
@@ -304,6 +308,7 @@ describe("serializedStateManager", () => {
 				storageAdapter,
 				true,
 				eventEmitter,
+				false,
 				() => false,
 				() => false,
 			);
@@ -355,6 +360,7 @@ describe("serializedStateManager", () => {
 				storageAdapter,
 				true,
 				eventEmitter,
+				false,
 				() => false,
 				() => false,
 			);
@@ -418,6 +424,7 @@ describe("serializedStateManager", () => {
 				storageAdapter,
 				true,
 				eventEmitter,
+				false,
 				() => false,
 				() => false,
 			);
@@ -459,6 +466,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 				);
@@ -519,6 +527,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 				);
@@ -571,6 +580,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 				);
@@ -634,6 +644,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					() => isDirty,
 					() => false,
 				);
@@ -666,6 +677,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 				);
@@ -737,6 +749,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 				);
@@ -787,6 +800,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					() => isDirty,
 					() => false,
 				);
@@ -822,6 +836,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					() => isDirty,
 					() => false,
 				);
@@ -873,6 +888,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 				);
@@ -974,6 +990,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 					snapshotRefreshTimeoutMs,
@@ -1043,6 +1060,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 					snapshotRefreshTimeoutMs,
@@ -1112,6 +1130,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 					snapshotRefreshTimeoutMs,
@@ -1176,6 +1195,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 					snapshotRefreshTimeoutMs,
@@ -1246,6 +1266,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 					snapshotRefreshTimeoutMs,
@@ -1313,6 +1334,7 @@ describe("serializedStateManager", () => {
 					storageAdapter,
 					true,
 					eventEmitter,
+					false,
 					isDirtyF,
 					() => false,
 					snapshotRefreshTimeoutMs,
@@ -1363,6 +1385,39 @@ describe("serializedStateManager", () => {
 					lastProcessedOpSequenceNumber,
 				);
 			});
+
+			it(`no snapshot refresh on storage only mode. isDirty: ${isDirty}`, async () => {
+				const storageAdapter = new MockStorageAdapter();
+				const saved = false;
+				const isDirtyF = (): boolean => (saved ? false : isDirty);
+				const serializedStateManager = new SerializedStateManager(
+					undefined,
+					enableOfflineSnapshotRefresh(logger),
+					storageAdapter,
+					true,
+					eventEmitter,
+					true,
+					isDirtyF,
+					() => false,
+					snapshotRefreshTimeoutMs,
+				);
+
+				await serializedStateManager.fetchSnapshot(undefined);
+				const lastProcessedOpSequenceNumber = 20;
+				let seq = 1;
+				while (seq <= lastProcessedOpSequenceNumber) {
+					serializedStateManager.addProcessedOp(generateSavedOp(seq++));
+				}
+				const snapshotSequenceNumber = 11; // latest snapshot will be among processed ops
+				storageAdapter.uploadSummary(snapshotSequenceNumber);
+				// snapshot refresh promise is undefined before timeout
+				const snapshotRefreshP = serializedStateManager.refreshSnapshotP;
+				assert.strictEqual(snapshotRefreshP, undefined);
+				clock.tick(snapshotRefreshTimeoutMs);
+				// now it's a promise
+				const initialRefreshP = serializedStateManager.refreshSnapshotP;
+				assert.strictEqual(initialRefreshP, undefined, "no refresh expected");
+			});
 		}
 	});
 });