// Test connection with node.
bool ElasticSearch::isActive() {

    Json::Object root;

    try {
        _http.get(0, 0, &root);
    }
    catch(Exception& e){
        printf("get(0) failed in ElasticSearch::isActive(). Exception caught: %s\n", e.what());
        return false;
    }
    catch(std::exception& e){
        printf("get(0) failed in ElasticSearch::isActive(). std::exception caught: %s\n", e.what());
        return false;
    }
    catch(...){
        printf("get(0) failed in ElasticSearch::isActive().\n");
        return false;
    }

    if(root.empty())
        return false;

    if(!root.member("status") || root["status"].getInt() != 200){
        printf("Status is not 200. Cannot find Elasticsearch Node.\n");
        return false;
    }

    return true;
}