# HTTP 525 errors via Cloudflare Worker

**URL:** <https://community.fly.io/t/http-525-errors-via-cloudflare-worker/5725>\
**Category:** General\
**Created:** [June 21, 2022, 6:37pm UTC](https://community.fly.io/t/http-525-errors-via-cloudflare-worker/5725 "2022-06-21T18:37:27Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![greg](https://sea1.discourse-cdn.com/fly1/user_avatar/community.fly.io/greg/32/2119_2.png) [@greg](https://community.fly.io/u/greg)\
**Post date:** [June 21, 2022, 6:56pm UTC](https://community.fly.io/t/http-525-errors-via-cloudflare-worker/5725/2 "2022-06-21T18:56:32Z")

</div>

Hmm. Certainly appears to be TLS related, given removing https fixes it, and the 525 code directly relates to that too. Unlike e.g a 500 or 504 etc.

My first thought, given those numbers, would be it could be related to _this_:

> [@max concurrency can not be greater than 300](https://community.fly.io/t/max-concurrency-can-not-be-greater-than-300/5710/6):
>
> This is expected behavior — there’s concurrency limits on TLS handshakes (max concurrent handshakes per IP). You’ll need to spread your test across several IPs to make it look more like organic traffic to get meaningful numbers.

Since I know Workers re-use a single instance, unlike e.g Lambda where is only one instance handling each request. And so it would follow the requests are coming from the same IP. Not quite sure how to avoid that _other_ than handle TLS in-app to avoid any Fly-proxy restriction.

---

_[View the full topic](https://community.fly.io/t/http-525-errors-via-cloudflare-worker/5725)._