fix: last seen metrics exceeding table limits (#7923)

## About the changes
When storing last seen metrics we no longer validate at insert time that
the feature exists. Instead, there's a job cleaning up on a regular
interval.

Metrics for features with more than 255 characters, makes the whole
batch to fail, resulting in metrics being lost.

This PR helps mitigate the issue while also logs long name feature names

src/lib/features/metrics/client-metrics/metrics-service-v2.test.ts

@@ -31,7 +31,6 @@ function initClientMetrics(flagEnabled = true) {
     const lastSeenService = new LastSeenService(
         {
             lastSeenStore: stores.lastSeenStore,
-            featureToggleStore: stores.featureToggleStore,
         },
         config,
     );

src/lib/features/metrics/last-seen/createLastSeenService.ts

@@ -1,5 +1,3 @@
-import FakeFeatureToggleStore from '../../feature-toggle/fakes/fake-feature-toggle-store';
-import FeatureToggleStore from '../../feature-toggle/feature-toggle-store';
 import type { Db, IUnleashConfig } from '../../../server-impl';
 import { FakeLastSeenStore } from './fake-last-seen-store';
 import { LastSeenService } from './last-seen-service';
@@ -15,21 +13,13 @@ export const createLastSeenService = (
         config.getLogger,
     );
 
-    const featureToggleStore = new FeatureToggleStore(
+    return new LastSeenService({ lastSeenStore }, config);
-        db,
-        config.eventBus,
-        config.getLogger,
-        config.flagResolver,
-    );
-
-    return new LastSeenService({ lastSeenStore, featureToggleStore }, config);
 };
 
 export const createFakeLastSeenService = (
     config: IUnleashConfig,
 ): LastSeenService => {
     const lastSeenStore = new FakeLastSeenStore();
-    const featureToggleStore = new FakeFeatureToggleStore();
 
-    return new LastSeenService({ lastSeenStore, featureToggleStore }, config);
+    return new LastSeenService({ lastSeenStore }, config);
 };

src/lib/features/metrics/last-seen/last-seen-service.ts

@@ -2,11 +2,7 @@ import type { Logger } from '../../../logger';
 import type { IUnleashConfig } from '../../../server-impl';
 import type { IClientMetricsEnv } from '../client-metrics/client-metrics-store-v2-type';
 import type { ILastSeenStore } from './types/last-seen-store-type';
-import type {
+import type { IUnleashStores } from '../../../types';
-    IFeatureToggleStore,
-    IFlagResolver,
-    IUnleashStores,
-} from '../../../types';
 
 export type LastSeenInput = {
     featureName: string;
@@ -20,36 +16,37 @@ export class LastSeenService {
 
     private lastSeenStore: ILastSeenStore;
 
-    private featureToggleStore: IFeatureToggleStore;
-
-    private config: IUnleashConfig;
-
-    private flagResolver: IFlagResolver;
-
     constructor(
-        {
+        { lastSeenStore }: Pick<IUnleashStores, 'lastSeenStore'>,
-            featureToggleStore,
-            lastSeenStore,
-        }: Pick<IUnleashStores, 'featureToggleStore' | 'lastSeenStore'>,
         config: IUnleashConfig,
     ) {
         this.lastSeenStore = lastSeenStore;
-        this.featureToggleStore = featureToggleStore;
         this.logger = config.getLogger(
             '/services/client-metrics/last-seen-service.ts',
         );
-        this.flagResolver = config.flagResolver;
-        this.config = config;
     }
 
     async store(): Promise<number> {
         const count = this.lastSeenToggles.size;
         if (count > 0) {
-            const lastSeenToggles = Array.from(this.lastSeenToggles.values());
+            const lastSeenToggles = Array.from(
-            this.lastSeenToggles = new Map<String, LastSeenInput>();
+                this.lastSeenToggles.values(),
+            ).filter((lastSeen) => lastSeen.featureName.length <= 255);
+            if (lastSeenToggles.length < this.lastSeenToggles.size) {
+                this.logger.warn(
+                    `Toggles with long names ${JSON.stringify(
+                        Array.from(this.lastSeenToggles.values())
+                            .filter(
+                                (lastSeen) => lastSeen.featureName.length > 255,
+                            )
+                            .map((lastSeen) => lastSeen.featureName),
+                    )}`,
+                );
+            }
             this.logger.debug(
                 `Updating last seen for ${lastSeenToggles.length} toggles`,
             );
+            this.lastSeenToggles = new Map<String, LastSeenInput>();
 
             await this.lastSeenStore.setLastSeen(lastSeenToggles);
         }

src/lib/features/metrics/last-seen/last-seen-store.ts

@@ -48,7 +48,6 @@ export default class LastSeenStore implements ILastSeenStore {
     async setLastSeen(data: LastSeenInput[]): Promise<void> {
         try {
             const inserts = prepareLastSeenInput(data);
-
             const batchSize = 500;
 
             for (let i = 0; i < inserts.length; i += batchSize) {

src/lib/features/metrics/last-seen/tests/last-seen-service.e2e.test.ts

@@ -133,3 +133,34 @@ test('should clean unknown feature flag environments from last seen store', asyn
 
     expect(stored.rows.length).toBe(2);
 });
+
+test('should not fail with feature names longer than 255 chars', async () => {
+    const { lastSeenService } = app.services;
+
+    const longFeatureNames = [
+        { name: 'a'.repeat(254), environment: 'default' },
+        { name: 'b'.repeat(255), environment: 'default' },
+        { name: 'c'.repeat(256), environment: 'default' }, // this one should be filtered out
+    ];
+
+    const inserts = [...longFeatureNames].map((feature) => {
+        return {
+            featureName: feature.name,
+            environment: feature.environment,
+            yes: 1,
+            no: 0,
+            appName: 'test',
+            timestamp: new Date(),
+        };
+    });
+
+    lastSeenService.updateLastSeen(inserts);
+    await lastSeenService.store();
+
+    // We have no method to get these from the last seen service or any other service or store
+    const stored = await db.rawDatabase.raw(
+        'SELECT * FROM last_seen_at_metrics;',
+    );
+
+    expect(stored.rows.length).toBe(2);
+});

src/lib/features/metrics/last-seen/tests/last-seen-service.test.ts

@@ -23,7 +23,6 @@ function initLastSeenService(flagEnabled = true) {
     const lastSeenService = new LastSeenService(
         {
             lastSeenStore: stores.lastSeenStore,
-            featureToggleStore: stores.featureToggleStore,
         },
         config,
     );