Filter services based on Eureka metadata with Zuul

Question

We use Spring Cloud Netflix Zuul along with Eureka in our environment.

I understand Ribbon obtains the server list from Eureka for specified serviceId. In our case we have 4 containers of a service, one of the container is the master which performs resource intense tasks. I would like to filter out master container from list of servers so Ribbon doesnt forward any requests to the container.

How do I filter ?

Any help is appreciated.

Answer 1

I was able to filter by creating a new custom IRule

 homeautomation.ribbon.NFLoadBalancerRuleClassName=com.example.CustomZoneAvoidanceRule

and extending the default ZoneAvoidanceRule

public class CustomZoneAvoidanceRule extends ZoneAvoidanceRule {

@Override
public Server choose(final Object key) {
    final Server server = super.choose(key);
    // code to skip specific instance based on eureka metadata.
    return server;
}

}