Communication patterns such as publish-subscribe provide new opportunities to actively deliver data and information to consumers as soon as it is available in near-real time. Opposed to this, traditional pull-based patterns follow a request-response approach which means that a consumer needs to request data and subsequently receives data that is available at the time of the request with a possible delay.

In several applications, push-based communication offers a significant added value. This is illustrated by the following two examples:

1.) Applications such as risk monitoring and alerting depend on the timely availability of the latest (observation) data (e.g. water level measurements, meteorological conditions, etc.). Push-based communication flows ensure that new information is immediately received by the relevant parties as soon as it has been published. Besides the minimized delay in data delivery, another advantage is the reduced load on the server infrastructure as consumers do not need to actively check for new data.

2.) An increasing number of geo-science applications consists of processes that create new information products from multiple inputs such as Earth Observation (e.g. Copernicus) and in-situ measurement networks (e.g. Sensor Webs). Often, the generation of such products shall be triggered by specific events (e.g. critical measurements of a sensor) or by the availability of new/updated input data (e.g. if a new satellite scene is available that fulfills certain quality requirements).

Within this session, we aim at collecting use cases of push-based data delivery flows, implementations, lessons learned, experiences with emerging technologies that enable publish-subscribe patterns as well as application examples. Based on this, we intent to derive recommendations on future directions for allowing more efficient dissemination of near-real-time data and push-based information flows in research data infrastructures.


Topics include:
- Technologies for enabling push/publish-subscribe communication patterns
- Triggering of geo-processing chains
- Monitoring and alerting applications
- Interoperability standards
- Discovery and metadata of (near) real-time data sources
- Sensor Web technologies
- Distributed event detection