Hi,

I am trying to use the following "NGINX upstream carp" module to realize upstream load balancing with a certain server affinity for requests.

https://github.com/olegloa/nginx-upstream-carp

The following basic configuration works fine.

upstream mybackends {
server 192.168.1.3:8720;
server 192.168.1.3:8721;
server 192.168.1.3:8722;

carp;
}

However, if I add a "zone" directive within the upstream block (which contains the carp directive also), the verification test for the configuration (using -t option) crashes.

upstream mybackends {

zone zone_for_mybackends 1m;

server 192.168.1.37:8720;
server 192.168.1.37:8721;
server 192.168.1.37:8722;

carp;
}

The presence of "carp" directive seems to be causing the issue here. From my analysis, the crash seems to be due to the "setting" of peer.data field by carp module, which leads to an invalid memory access in the upstream zone code.

The carp-module code seems to be developed 6-7 years ago, and I guess it is probably not fully compatible with the latest NGINX upstream constructs like zone.

If someone else is using carp module and has faced this problem, could you please explain how it can be resolved?

Thanks
Rajesh