Apache Karaf provides a monitoring and alerting solution called Apache Karaf Decanter. OpenDaylight users can configure this system to provide their deployments with an easy-to-read status dashboard and take advantage of advanced capabilities such as Service Level Agreement (SLA) alerting.
As of OpenDaylight Beryllium, Decanter support is experimental. Platform level monitoring is possible; application specific monitoring requires custom Collectors (and/or configurations) and Kibana dashboard updates (Kibana is a browser-based analytics and search dashboard for Elasticsearch).