About a week to 10 days ago, one of our customers reported slowness on our web application, which is proxied by Cloudflare.
The issue is with one specific operation, which is executed at frontend, and calls a backend service to fetch data. When Cloudflare is enabled, the operation is taking over 20 to 30 seconds. When we disable proxy to our product, the operation takes less about 2 seconds.
Only this specific operation seems to be affected, and what is curious is that only ONE customer is experiencing this issue, when accessing our product from their network. We managed to reproduce the issue from their network—both in our production and test environments.
We did several tests from other networks, which works fine with Cloudflare turned on. We have also turned-on Developer mode Cloudflare and manually cleared cache, but it has no effect. The issue seems to be related only Cloudflare proxy, not cache.
We are inclined to believe that this is an issue at the customer site, since they’re the only ones experiencing this issue, but we need to be able to identify what the issue is to point them at the right direction towards a fix. For now, we had to disable Cloudflare proxy, since this customer is a major account.
Any help is appreciated.
Best,
P.