I found this sbange's answer about unique request ID in nginx upstreams. Here is a quote:
location / {
proxy_pass http://upstream;
proxy_set_header X-Request-Id $pid-$msec-$remote_addr-$request_length;
}
It's looks nice, but it generates long and not very useful string. It would be better with a short hash (md5 for example).
Then I found this third-party nginx module ngx_http_set_hash. And of course, I can use a perl_modules for md5 functions. But, I trying to find some out-of-box, just with Nginx.
Can Nginx make hash value of some string or maybe someone know better method for generating short unique request id?