Fight against the bursts

[CharlesNepote]

Some buggy apps/tools are making dozens of requests of the same URL in the same second. Unfortunately, the cache does not seem to work in this case (nginx probably don't have time to fill the cache).
Eg. (look at the [MISS] at the end of the lines, telling that the cache is not used):

xxx.xxx.xxx.xxx - - [11/Jun/2024:19:14:05 +0000] "GET /api/v3/product/https://app.adjust.com/6iofau3/?lc=de&tags_lc=de&fields=product_name%2Cbrands%2Cimage_front_url%2Cnutriments%2Ccode%2Cproduct_quantity%2Cserving_quantity&app_name=MCI+-+Personal+Training+AI&app_version=1.1.990+1&app_platform=iOS&comment=use+website+for+contact+and+more+information HTTP/1.1" 404 689 "-" "- MCI - Personal Training AI - 1.1.990 1 - iOS - https://mcisolutions.de - use website for contact and more information" "-" MISS [1.720]
xxx.xxx.xxx.xxx - - [11/Jun/2024:19:14:05 +0000] "GET /api/v3/product/https://app.adjust.com/6iofau3/?lc=de&tags_lc=de&fields=product_name%2Cbrands%2Cimage_front_url%2Cnutriments%2Ccode%2Cproduct_quantity%2Cserving_quantity&app_name=MCI+-+Personal+Training+AI&app_version=1.1.990+1&app_platform=iOS&comment=use+website+for+contact+and+more+information HTTP/1.1" 404 689 "-" "- MCI - Personal Training AI - 1.1.990 1 - iOS - https://mcisolutions.de - use website for contact and more information" "-" MISS [1.844]
xxx.xxx.xxx.xxx - - [11/Jun/2024:19:14:05 +0000] "GET /api/v3/product/https://app.adjust.com/6iofau3/?lc=de&tags_lc=de&fields=product_name%2Cbrands%2Cimage_front_url%2Cnutriments%2Ccode%2Cproduct_quantity%2Cserving_quantity&app_name=MCI+-+Personal+Training+AI&app_version=1.1.990+1&app_platform=iOS&comment=use+website+for+contact+and+more+information HTTP/1.1" 404 689 "-" "- MCI - Personal Training AI - 1.1.990 1 - iOS - https://mcisolutions.de - use website for contact and more information" "-" MISS [1.936]
xxx.xxx.xxx.xxx - - [11/Jun/2024:19:14:05 +0000] "GET /api/v3/product/https://app.adjust.com/6iofau3/?lc=de&tags_lc=de&fields=product_name%2Cbrands%2Cimage_front_url%2Cnutriments%2Ccode%2Cproduct_quantity%2Cserving_quantity&app_name=MCI+-+Personal+Training+AI&app_version=1.1.990+1&app_platform=iOS&comment=use+website+for+contact+and+more+information HTTP/1.1" 404 689 "-" "- MCI - Personal Training AI - 1.1.990 1 - iOS - https://mcisolutions.de - use website for contact and more information" "-" MISS [1.784]
xxx.xxx.xxx.xxx - - [11/Jun/2024:19:14:05 +0000] "GET /api/v3/product/https://app.adjust.com/6iofau3/?lc=de&tags_lc=de&fields=product_name%2Cbrands%2Cimage_front_url%2Cnutriments%2Ccode%2Cproduct_quantity%2Cserving_quantity&app_name=MCI+-+Personal+Training+AI&app_version=1.1.990+1&app_platform=iOS&comment=use+website+for+contact+and+more+information HTTP/1.1" 404 689 "-" "- MCI - Personal Training AI - 1.1.990 1 - iOS - https://mcisolutions.de - use website for contact and more information" "-" MISS [1.828]
xxx.xxx.xxx.xxx - - [11/Jun/2024:19:14:05 +0000] "GET /api/v3/product/https://app.adjust.com/6iofau3/?lc=de&tags_lc=de&fields=product_name%2Cbrands%2Cimage_front_url%2Cnutriments%2Ccode%2Cproduct_quantity%2Cserving_quantity&app_name=MCI+-+Personal+Training+AI&app_version=1.1.990+1&app_platform=iOS&comment=use+website+for+contact+and+more+information HTTP/1.1" 404 689 "-" "- MCI - Personal Training AI - 1.1.990 1 - iOS - https://mcisolutions.de - use website for contact and more information" "-" MISS [2.432]

In theory, we can manage this in nginx with the proxy_cache_lock directive. There's an interesting article about it.
It might be used in conjonction with proxy_cache_use_stale updating. See:

• https://www.mail-archive.com/[email protected]/msg12044.html
• https://stackoverflow.com/questions/54061978/nginx-use-proxy-cache-lock-logic-when-cache-expired-in-order-to-avoid-multi-up

It should be easy to test this.