private ApplicationMetaData readMetaDataFromActiveApp(ZKApplication activeApp) {
        Path metaPath = Path.fromString(ZKApplication.META_ZK_PATH);
        String metaDataString = activeApp.getData(metaPath);
        if (metaDataString == null || metaDataString.isEmpty()) {
            return null;
        }
        return ApplicationMetaData.fromJsonString(activeApp.getData(metaPath));
    }
Reads allocated hosts at the given node.

@return the allocated hosts at this node or empty if there is no data at this path
configserver/src/main/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationPackage.java