I'm serving Images as part of my website for a long time now, but recently images became too slow on a certain ISP!
I'm hosting on DigitalOcean with a load balancer (with http2 rule) in front of multiple app server droplets using Nginx on Ubuntu, & images are being loaded from a database with acl on them when needed.
Here is the sample image (345 KB) I'm testing with, which loads very normally on 2 ISPs, but loads tooooo slow on a 3rd ISP as follows:
- Vodafone ISP (3G)
- Image load time: 0.8 S (Seconds)
- ISP Speed test: 17 Mbps
- Vodafone ISP (Adsl)
- Image load time: 1 S
- ISP Speed test: 11 Mbps
- Orange ISP (Adsl)
- Image load time: 2 S
- ISP Speed test: 1.6 Mbps
- We ISP (Adsl)
- Image load time: 27 S
- ISP Speed test: 3.5 Mbps
(note: these numbers are averages but almost consistent)
I know it is a very weird behavior, but it is consistent for several days now.
Question is how to start even debugging this issue to be able to fix it?!!