@Override
    public void removeHosts(ApplicationInstanceReference reference, Set<HostName> hostnames) {
        ApplicationId application = OrchestratorUtil.toApplicationId(reference);

        // Needed for VESPA-18864:
        log.info("Removing host status for " + application + ": " + hostnames);

        // Remove /vespa/host-status/APPLICATION_ID/hosts/HOSTNAME
        hostnames.forEach(hostname -> curator.delete(Path.fromString(hostPath(application, hostname))));
    }
Handles all ZooKeeper data structures related to each active application, including HostInfo.
Cache (if any) is above and not visible here.

@author hakonhall
orchestrator/src/main/java/com/yahoo/vespa/orchestrator/status/HostInfosServiceImpl.java