upstream+ip_hash: hash valid global? (no replies)

Hello,

i have 2 upstreams, each with 3 backend servers, where backendA is the same backend in both upstreams.

upstream one {
server backendA;
server backendB;
server backendC;
}

upstream two {
server backendA;
server backendD;
server backendE;
}

A user with his IP sends a request, gets passed to upstream one and is sent to backendA. Shortly after that he sends a different request and gets passed to upstream two - will he be sent to backendA as well?

So the question is: is ip_hash global in nginx, i.e. a user always is sent to the same backend (if available), independent from an upstream? Or is ip_hash upstream-specific, i.e. nginx hashes per upstream?

thx in advance
revirii