Fix workflow cron trigger cache stuck without TTL (#20812)

## Problem

The cron-trigger cache key (`module:workflow:workflow-cron-triggers`)
can get stuck without a TTL, silently halting **all** cron-triggered
workflows for a whole tenant until the key is manually deleted from
Redis.

Repro path:

1. Cache miss → DB-scan branch runs.
2. Inner loop writes triggers via `hashSet` (creates the key, **no TTL
yet**).
3. Worker crashes / OOMs / gets killed by a deploy between any `hashSet`
and the trailing `expire(1h)` call.
4. Key now exists with TTL = `-1` and a partial set of fields.
5. Next tick: `hashGetValues` returns those fields →
`cachedValues.length > 0` → **cache-hit branch** → `expire` is never
called.
6. Key has no TTL, so it never auto-expires. The DB-scan branch never
runs again. New / missing triggers are never picked up. Workflows go
silent.

Observed in production: cache key with `TTL: no limit` and 121 fields.
Deleting the key restored normal behaviour (next tick rebuilt with TTL
~3600).

## Fix

Set the TTL right after first value is added 

## Monitoring

Added a "Cache miss" log count in workflow dashboard, counted among the
last 6 hours. Turns green if >= 5
<img width="1627" height="721" alt="Screenshot 2026-05-21 at 16 46 13"
src="https://github.com/user-attachments/assets/8262dd5f-fbbd-43c9-aede-c0ce5d6a0f59"
/>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/twenty-server/src/engine/core-modules/cache-storage/services/cache-storage.service.ts

@@ -342,6 +342,31 @@ end`;
     }) as Promise<number>;
   }
 
+  async hashSetWithExpire({
+    key,
+    field,
+    value,
+    ttlMs,
+  }: {
+    key: string;
+    field: string;
+    value: string;
+    ttlMs: Milliseconds;
+  }): Promise<void> {
+    if (!this.isRedisCache()) {
+      throw new Error('hashSetWithExpire is only supported with Redis cache');
+    }
+
+    const redisClient = (this.cache as RedisCache).store.client;
+    const prefixedKey = this.getKey(key);
+
+    await redisClient
+      .multi()
+      .hSet(prefixedKey, field, value)
+      .pExpire(prefixedKey, ttlMs)
+      .exec();
+  }
+
   async hashDelete({
     key,
     field,

packages/twenty-server/src/modules/workflow/workflow-trigger/automated-trigger/crons/jobs/__tests__/workflow-cron-trigger-cron.job.spec.ts

@@ -32,7 +32,7 @@ const mockExceptionHandlerService = {
 const mockCacheStorageService = {
   hashGetValues: jest.fn(),
   hashSet: jest.fn(),
-  expire: jest.fn(),
+  hashSetWithExpire: jest.fn(),
 };
 
 describe('WorkflowCronTriggerCronJob', () => {
@@ -156,6 +156,7 @@ describe('WorkflowCronTriggerCronJob', () => {
       await job.handle();
 
       expect(mockCacheStorageService.hashSet).not.toHaveBeenCalled();
+      expect(mockCacheStorageService.hashSetWithExpire).not.toHaveBeenCalled();
     });
   });
 
@@ -175,7 +176,7 @@ describe('WorkflowCronTriggerCronJob', () => {
       expect(mockCoreDataSource.query).toHaveBeenCalledTimes(3);
     });
 
-    it('should write each trigger to cache immediately and set TTL', async () => {
+    it('should use hashSetWithExpire for every trigger so the TTL is always set', async () => {
       mockCacheStorageService.hashGetValues.mockResolvedValue([]);
       mockWorkspaceRepository.find.mockResolvedValue([
         { id: WORKSPACE_1 },
@@ -202,28 +203,39 @@ describe('WorkflowCronTriggerCronJob', () => {
 
       await job.handle();
 
-      expect(mockCacheStorageService.hashSet).toHaveBeenCalledTimes(2);
-      expect(mockCacheStorageService.hashSet).toHaveBeenCalledWith({
-        key: WORKFLOW_CRON_TRIGGER_CACHE_KEY,
-        field: 'workflow-1',
-        value: JSON.stringify({
-          workspaceId: WORKSPACE_1,
-          workflowId: 'workflow-1',
-          pattern: '* * * * *',
-        }),
-      });
-      expect(mockCacheStorageService.hashSet).toHaveBeenCalledWith({
-        key: WORKFLOW_CRON_TRIGGER_CACHE_KEY,
-        field: 'workflow-2',
-        value: JSON.stringify({
-          workspaceId: WORKSPACE_3,
-          workflowId: 'workflow-2',
-          pattern: '* * * * *',
-        }),
-      });
-      expect(mockCacheStorageService.expire).toHaveBeenCalledWith(
-        WORKFLOW_CRON_TRIGGER_CACHE_KEY,
-        WORKFLOW_CRON_TRIGGER_CACHE_TTL_MS,
+      // hashSet must never be called during a rebuild: any non-atomic write
+      // could recreate the key without a TTL if it was flushed/evicted
+      // mid-rebuild, leaving cron workflows permanently stuck.
+      expect(mockCacheStorageService.hashSet).not.toHaveBeenCalled();
+
+      expect(mockCacheStorageService.hashSetWithExpire).toHaveBeenCalledTimes(
+        2,
+      );
+      expect(mockCacheStorageService.hashSetWithExpire).toHaveBeenNthCalledWith(
+        1,
+        {
+          key: WORKFLOW_CRON_TRIGGER_CACHE_KEY,
+          field: 'workflow-1',
+          value: JSON.stringify({
+            workspaceId: WORKSPACE_1,
+            workflowId: 'workflow-1',
+            pattern: '* * * * *',
+          }),
+          ttlMs: WORKFLOW_CRON_TRIGGER_CACHE_TTL_MS,
+        },
+      );
+      expect(mockCacheStorageService.hashSetWithExpire).toHaveBeenNthCalledWith(
+        2,
+        {
+          key: WORKFLOW_CRON_TRIGGER_CACHE_KEY,
+          field: 'workflow-2',
+          value: JSON.stringify({
+            workspaceId: WORKSPACE_3,
+            workflowId: 'workflow-2',
+            pattern: '* * * * *',
+          }),
+          ttlMs: WORKFLOW_CRON_TRIGGER_CACHE_TTL_MS,
+        },
       );
     });
 
@@ -235,7 +247,7 @@ describe('WorkflowCronTriggerCronJob', () => {
       await job.handle();
 
       expect(mockCacheStorageService.hashSet).not.toHaveBeenCalled();
-      expect(mockCacheStorageService.expire).not.toHaveBeenCalled();
+      expect(mockCacheStorageService.hashSetWithExpire).not.toHaveBeenCalled();
     });
   });
 

packages/twenty-server/src/modules/workflow/workflow-trigger/automated-trigger/crons/jobs/workflow-cron-trigger-cron.job.ts

@@ -125,22 +125,17 @@ export class WorkflowCronTriggerCronJob {
       );
 
       for (const trigger of triggersToCache) {
-        await this.cacheStorageService.hashSet({
+        await this.cacheStorageService.hashSetWithExpire({
           key: WORKFLOW_CRON_TRIGGER_CACHE_KEY,
           field: trigger.workflowId,
           value: JSON.stringify(trigger),
+          ttlMs: WORKFLOW_CRON_TRIGGER_CACHE_TTL_MS,
         });
+
         triggerCount++;
       }
     }
 
-    if (triggerCount > 0) {
-      await this.cacheStorageService.expire(
-        WORKFLOW_CRON_TRIGGER_CACHE_KEY,
-        WORKFLOW_CRON_TRIGGER_CACHE_TTL_MS,
-      );
-    }
-
     this.logger.log(`Cache rebuilt with ${triggerCount} cron triggers`);
   }