Repository --> Charts taking too long, then dropping to 503 (FOR BIG REPOSITRIES ONLY)

Summary

For big repositories(Up to now I tested with a 2.5GB repo on my own omnibus installation & 5.6GB repo in gitlab.com directly(https://gitlab.com/superna9999/linux)) clicking repository --> Charts will take too long & eventually fail with error 503. You can check the behaviour yourself on https://gitlab.com/superna9999/linux.

Steps to reproduce

Go to https://gitlab.com/superna9999/linux --> Click repository -> chart & wait for it to fail. This is also the same behavior on our own omnibus installation.

What is the current bug behavior?

clicking repository --> Charts will take too long & eventually fail with error 503

What is the expected correct behavior?

Either it does not fail, or if it fails pushes an explanatory message how we can work around this.

Relevant logs

No logs attached as this issue can also be reproduced on gitlab.com itself.