Cron Job State Persistence #

✅ Problem Solved #

Issue: Cron job enabled/disabled state was lost on server restart (only stored in memory)

Solution: Implemented persistent storage in database using SystemSetting table

🗄️ How It Works #

Storage Location #

• Table: SystemSetting
• Category: cronJobs
• Keys: pledge, oneoff, recurring, hourly
• Value Type: boolean

Database Schema #

SELECT * FROM "SystemSetting" WHERE category = 'cronJobs';

-- Results:
id                | category  | key       | value | valueType
------------------|-----------|-----------|-------|----------
clx123...         | cronJobs  | pledge    | true  | boolean
clx456...         | cronJobs  | oneoff    | false | boolean
clx789...         | cronJobs  | recurring | true  | boolean
clxabc...         | cronJobs  | hourly    | true  | boolean

🔄 Lifecycle #

Startup (onModuleInit) #

1. Load states from database
2. If none exist → create default settings (all enabled)
3. Load into memory for fast access
4. Log success/failure

During Runtime #

• States checked from in-memory (fast)
• Changes persisted to database immediately
• Database serves as source of truth

Shutdown & Restart #

• Memory cleared
• On next startup → reload from database
• Your settings are preserved!

📊 Features #

✅ Persistence #

• Settings survive server restarts
• Database is source of truth
• Auto-initialization on first run

✅ Performance #

• In-memory cache for speed
• Database write on change only
• Fast reads during runtime

✅ Reliability #

• Fallback to defaults if database fails
• Graceful error handling
• Continues working even if DB is down (memory only)

✅ Auto-initialization #

• Creates default settings on first run
• All jobs start enabled by default
• No manual setup required

🔍 Example Flow #

First Server Start #

1. Load from DB → No records found
2. Create defaults → All enabled
3. Store in DB
4. Load into memory
✅ Ready!

Disable Pledge Jobs #

1. User toggles pledge job to OFF
2. Update memory: pledge = false
3. Persist to DB: UPSERT SystemSetting
4. Log: "Cron job pledge disabled"
✅ Saved!

Server Restart #

1. Load from DB → Loads pledge = false
2. Load into memory
3. Pledge jobs skip execution
✅ Settings preserved!

Re-enable Pledge Jobs #

1. User toggles pledge job to ON
2. Update memory: pledge = true
3. Persist to DB: UPSERT SystemSetting
4. Next scheduled run → Job executes
✅ Back online!

🎯 Code Changes #

CronJobStateService #

// Before: In-memory only
private jobStates = new Map([...]);

// After: Persistent with DB
async onModuleInit() {
  await this.loadStatesFromDatabase();
}

async setJobEnabled(jobType: string, enabled: boolean) {
  // Memory + Database
  this.jobStates.set(jobType, enabled);
  await this.prisma.systemSetting.upsert({...});
}

📋 Database Queries #

Check Current States #

SELECT key, value 
FROM "SystemSetting" 
WHERE category = 'cronJobs';

-- Output:
key       | value
----------|-------
pledge    | true
oneoff    | false
recurring | true
hourly    | true

Manually Update State #

UPDATE "SystemSetting" 
SET value = 'false', "updatedAt" = NOW()
WHERE category = 'cronJobs' AND key = 'pledge';

Reset to Defaults #

UPDATE "SystemSetting" 
SET value = 'true', "updatedAt" = NOW()
WHERE category = 'cronJobs';

✅ Verification #

Test the persistence:

1. Start server: All jobs enabled by default
2. Disable a job: Use API or dashboard
3. Restart server: npm run start:dev
4. Check: Job remains disabled ✅

🎉 Summary #

Problem: Settings lost on restart ❌
Solution: Database persistence ✅
Result: Your on/off settings survive restarts! 🎉