Intermittent 502 errors from proxy rewrite and long load times

Support
1

I have a very basic static web page that is set up to proxy requests through rewrite. The toml looks something like this:

[[redirects]]
from = “/api/infer/base64”
to = “http://54.85.134.170:8080/infer/base64”
status = 200
force = true
headers = {X-From = “Netlify”}

When working with this API locally (vite config to also proxy my local web server to that IP/route), everything responds fast and there never are any issues.

However, when I deployed to Netlify the static assets, I am sometimes seeing long requests and even 502s.

Here are a few request IDs:

x-nf-request-id: 01GCM4R9QV94NTMWVHZ3F5RPAA (took ~16s)
x-nf-request-id: 01GCM4ZG5KD60N1XBR9W37YQK3 (error 502 after 700ms)

Things do work about ~75% of the time, but what gives?

3

I can see the same error for both those IDs in our logs:

msg="unable to buffer request body" error="request body too large"

Are you using that for a file upload? Could you let us know the size of the files you’re trying to upload?

5

Kind of. The post body has potential large base64 strings of images.

How come sometimes the request errors and sometimes not? I am sending the same payload. Is it hitting a load balancer and certain proxy servers have a different limit on size?

6

I’d assume the limit to be same on all nodes. Do you know the length of the body though? I’d like to try sending a similar string myself to test.

7

The image is about 7.7MB but I’m unsure how much that is in base64 string and compressed. Here is a sample image

couscous_1 (1)
couscous_1 (1)1920×2560 752 KB

8

You can go to my app assuming you can look up the URL and just upload that file. The network tab can get you the exact query

10

Thanks! While I couldn’t use your image as Discourse compressed it, I tried to use another large image on a test site and it appears to be an issue. I wasn’t aware of any such limits yet, so I’ve escalated this to the devs to confirm about this.

We’d let you know as we have more information.

11

Hey @ssesfahani,

We heard back from the engineers, and it turns out, we have a 8 MB upload limit for performance reasons. You only get the error sometimes, because we are only buffering the body in specific situations.

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