Why is the 400 Bad Request Request Header Or Cookie Too Large error?

Question

Apache HTTP Server

There is a store on opencart. Instead of pages, clients sometimes get 400 Bad Request
Request Header Or Cookie Too Large Appears after sitting at the site for a long time.
Doesn't appear for me. Tell me where to dig?

Answer 1

400 Bad Request Request Header Or Cookie Too Large

Answer 2

/etc/nginx/nginx.conf

I had such garbage because of these parameters:

client_body_buffer_size 10K;
client_header_buffer_size 1k;
client_max_body_size 8m;
large_client_header_buffers 2 1k;