private Optional<byte[]> readBytesFromZk(String path) throws Exception {
        try {
            return Optional.of(curator.framework().getData().forPath(path));
        } catch (NoNodeException e) {
            return Optional.empty();
        }
    }
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