node.js - Load balancing with nginx using hash method -

i want use nginx load balancer in front of several node.js application nodes.

round-robin , ip_hash methods unbelievably easy implement in use case, they're not best fit.

i need nginx serve clients backend nodes in respect session id's given first-landed node.

during googlings, i've come "hash"ing method couldn't find many resources around.

here tried:

my_site.conf:

http {      upstream my_servers {         hash $remote_addr$http_session_id consistent;         server 127.0.0.1:3000;         server 127.0.0.1:3001;         server 127.0.0.1:3002;     }      server {         listen 1234;         server_name example.com;          location / {             proxy_pass http://my_servers;             proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;             proxy_redirect off;             proxy_buffering off;             proxy_set_header        x-real-ip       $remote_addr;             proxy_set_header        x-forwarded-for $proxy_add_x_forwarded_for;         }     } } 

and @ application, return session-id header session id.

res.setheader('session-id', req.sessionid); 

i'm missing something, what?

$http_session_id refers header sent client (browser), not application response. , need http://nginx.org/r/sticky, it's in commercial subscription only.

there third-party module same commercial one, you'll have recompile nginx.