Oddly high traffic

I’m experiencing continuous, high-volume outbound traffic from my Next.js application deployed on Vercel. The traffic is suspicious and happens continuously (not just on page load), primarily from the `[category]` and `products/[slug]` pages. When monitoring Vercel logs and outbound traffic metrics, I see:

1. Continuous outbound requests happening even when pages are idle

2. High volume of requests that seems disproportionate to actual user activity

I need help identifying:

1. What is causing continuous outbound traffic when pages should be idle?

2. Are analytics services (PostHog, Sentry, Vercel Analytics) making excessive requests?

3. Could there be client-side polling or background processes I’m not aware of?

4. How can I identify and debug the source of this continuous traffic?

**Current Behavior:**

- **Continuous outbound traffic** even when pages are idle (not just on initial load)

- High volume of requests that seems suspicious and disproportionate

- Traffic persists across `[category]` and `products/[slug]` pages

**Expected Behavior:**

- Outbound traffic should only occur on:

- Initial page load (images, analytics initialization)

- User interactions (clicks, form submissions)

- Legitimate background processes (with known intervals)

- No continuous traffic when pages are idle

- Analytics should batch and throttle requests appropriately

- Image loading should be optimized and not cause continuous requests

**Steps to Reproduce:**

1. Deploy Next.js app to Vercel

2. Navigate to any category page (e.g., `/tiles`) or product page (e.g., `/products/some-product`)

3. **Leave the page idle** (no user interaction)

4. Monitor Vercel logs and outbound traffic metrics in real-time

5. Observe **continuous outbound requests** even when page is idle

6. Check network tab in browser dev tools to see what’s making requests

7. Review Vercel Analytics dashboard for outbound traffic patterns

**What I’ve Already Checked:**

- No obvious `setInterval` or polling mechanisms in client-side code

- PostHog is configured with default settings (may be making frequent requests)

- Sentry is enabled with `tracesSampleRate: 1` (100% sampling - could be excessive)

- Vercel Analytics is enabled

- Images are lazy-loaded, but there may still be continuous requests

**Project Information:**

- **URL:** www.cortina.ae

- **Framework:** Next.js 16.0.10 (App Router)

- **Deployment:** Vercel (Production)

- **Database:** NeonDB (PostgreSQL) - Serverless

- **ORM:** Drizzle ORM with `drizzle-orm/neon-http`

- **Region:** Washington D.C. (primary region showing high request volume)

- **Caching:** Using `unstable_cache` with 1-hour revalidation for product queries

- **Image Hosting:** Sanity CDN (`cdn.sanity.io`)

- **Environment:** Production

**Key Dependencies:**

- `drizzle-orm`: Latest

- `@neondatabase/serverless`: Latest

- `next`: 16.0.10

**Configuration:**

- Using direct `DATABASE_URL` (not connection pooling URL)

- No explicit connection pooling configuration

- Serverless functions with default Vercel settings

**Analytics Configuration:**

```typescript

// PostHog Configuration

posthog.init(process.env.NEXT_PUBLIC_POSTHOG_KEY!, {

api_host: ‘/ingest’,

ui_host: ‘https://us.posthog.com’,

});

// Using default PostHog settings - may be making frequent requests

// Sentry Configuration

tracesSampleRate: 1, // 100% sampling - could be excessive

tracesSampleRate: 0.8, // In Next.js config

// Vercel Analytics

import { Analytics } from ‘@vercel/analytics/react’;

// Enabled in root layout

```

**Questions for Vercel Team:**

1. **How can I identify the source of continuous outbound traffic?** Are there Vercel dashboard tools or logs that show request destinations?

2. **Are PostHog, Sentry, or Vercel Analytics known to make continuous background requests?** Should I configure them differently?

3. **Could Next.js Image Optimization be making continuous requests** to optimize images on-demand?

4. **Are there Vercel-specific monitoring tools** to track outbound requests by destination domain/service?

5. **What’s the best way to debug continuous outbound traffic** in a Next.js app on Vercel?

6. **Should I be concerned about the high volume**, or is this normal for analytics-enabled Next.js apps?

7. **Are there rate limiting or throttling configurations** I should implement for analytics services?

Hey there, @oalbacha! Just checking in on your issue with the continuous high-volume outbound traffic from your Next.js app. Have you found a solution, or do you still need some help with this?

Hi @pawlean Not yet and it is driving me insane. How would I know what is causing the high traffic? Can you please help?

Right I enabled AI bot protection under firewall > manage bots and all the high traffic was significantly reduced.

2 Likes

Thanks for coming back and sharing what worked for you, @oalbacha! :smiley: