# NGINX Error: Upstream Sent Too Big Header While Reading Response Header from Upstream

NGINX is not able to read the header that is sent from the upstream as it is bigger than the configured size and the request is failing. In the NGINX error log (locating in: /var/log/nano\_agent/rpmanager/nginx\_log/error.log): "...\*1435367 upstream sent too big header while reading response header from upstream ..."

The configured buffer that caches the responses is too small.

**WHAT TO DO?**

1. Open the Infinity Portal
2. Click on **Cloud** tab → **Assets**
3. Navigate to the relevant asset and click on it.
4. Click on **Advanced...** (Under the certificate section), and click on **Additional Settings**\
   ![](https://2760087783-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FEWA4nfgNrSRL8dA6Kap7%2Fuploads%2FPNuXtk2AGNJitpNp1PZZ%2Fimage.png?alt=media\&token=4bcfdbd0-b5a0-495e-ac0b-1b43842cb066)
5. Mark V on the **Additional Location Block** Instruction checkbox and upload a .txt file with these lines in it:\
   `proxy_buffer_size          128k;`\
   `proxy_buffers              4 256k;`\
   `proxy_busy_buffers_size    256k;`\
   \
   ![](https://2760087783-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FEWA4nfgNrSRL8dA6Kap7%2Fuploads%2FpK992KZpAjlFG2CqCCUH%2Fimage.png?alt=media\&token=2e1d5646-0d67-4901-9624-4814c2407903)
6. Click **OK**.
7. **Enforce** the policy.