Data access and its implementation at Wendelstein 7-X

The Wendelstein 7-X stellarator experiment by its nature has the need for continuous live data monitoring. New technical and security related requirements make a redesign of the monitoring architecture, originating in the first years of the century, necessary. Besides that, new developments in technologies, user interfaces and generally IT supported work flows, generate new expectations at the system user level, including live remote participation.To answer these upcoming demands, the CoDaC team at Wendelstein 7-X has designed a new architecture for monitoring data management, distribution and observation. As a very flexible user interface, a client web application was developed, utilizing modern technologies like WebSockets and WebGL for high performance live data visualization. A touch friendly interface design offers both broad support for new access tools (like tablets, smart phones, smart TV sets) and a very flexible and intuitive work flow. This paper describes the new MonA-LISA monitoring architecture and gives a short overview over the options provided by the web based monitoring client.

Section: Monitoring At W7-xmentioning

confidence: 99%

Next generation web based live data monitoring for W7-X

Dumke

Riemann

Bluhm

et al. 2018

“…This implies a novel requirement of "read immediately after write" to the data archive as well as the overall CoDaC system. For an early proposal of the data acquisition see [5] and for more details regarding the archival architecture have a look at [6] and [7]. Figure 1 shows how the participating components interact with each other: CoDaStation is responsible for data acquisition and may perform simple online analysis during acquisition [5].…”

Section: Key Requirements For Continuous Operation and Its Implicationsmentioning

confidence: 99%

“…Online Data Monitoring [6] is used to visualize reduced data during experiments independent of archival using strip chart plots. Data Browser [7] allows to display archived data by user selection. Manifold quality requirements regarding performance efficiency (e.g.…”

Section: Key Requirements For Continuous Operation and Its Implicationsmentioning

confidence: 99%

Three novel software tools for ASDEX Upgrade

Martinov

Löbhard²,

Lunt

et al. 2016

ArchiveDB is the data archive for all scientific and technical data collected at the Wendelstein 7-X project. It is a distributed system allowing continuous data archival. ArchiveDB has demanding requirements regarding performance efficiency (storage performance of 30 GB/s during experiments, expected storage amount of 1.4 PB/year), reliability (availability of 364 days/year), maintainability (testability) and portability (including change of hardware and software). Data acquisition with continuous operation and high time resolutions (up to nanoseconds scale) for physics data is supported as well as long-term recording up to 24hour/7days for operational data (~1Hz rate). Moreover, all results of data analysis are stored in the archive. Another challenge, uniform retrieval of measured and analyzed data, allowing time and structure information as selection criteria, is mastered as well. The key concepts of data storage and retrieval are: (1) partitioning of incoming data in groups and stream, (2) chunking of data in boxes of manageable size covering a finite time period, and (3) indexing of data using absolute time as ordering and indexing criteria. Continuous operation of the ArchiveDB software and hardware for various systems and components relevant to Wendelstein 7-X has been done successfully for several years, thus, showing that the key requirements are satisfied. The overall data amount so far has reached 7 Terabyte over 9 years of data taking. Round-the-clock operation of the archive is in place since 5 years. Initial plasma operation OP1.1 of Wendelstein 7-X has been supported with no downtime during the whole experimental campaign. The paper describes the software engineering concepts that have been used, consolidated and refined over the years of continuing productive ArchiveDB use and development. Changes in the underlying techniques, e.g. a change of the data store, have been encapsulated via an Application Programming Interface (API). This API unifies different implementations and is also suitable for data migration.

“…Because of its importance for offline data browsing this application will be described more detailed in the following chapter. For users who want to import data into their own applications it is of course also possible to integrate the Data Access Layer interface [11] which is used by the Data Browser. Since this is a Java based interface it can only be used by Java capable applications.…”

Section: Figure 1: Experiments Viewsmentioning

confidence: 99%

Common browsing and retrieval of technical and experimental data for steady state experiments

Bluhm

Heimann

Hennig

et al. 2009

Steady state experiments like Wendelstein 7-X have to deal with large amounts of data of different kind. Discharge lengths may last from less than a second up to 30 minutes. During this time diagnostics will measure data in different discharge phases with different rates depending on the physical program. Furthermore the technical configuration of all devices must be logged during the discharge as well as between experiment phases. This is necessary to allow supervision of constantly running devices. All measured data must be stored together in a common database to make it easily accessible and reduce the effort to combine data. Because of these requirements a continuous data acquisition system must be provided where data may exist at any time. Intelligent methods for browsing and retrieval of the acquired data from the common database are desired. This includes calendar based time interval selection, overview plots for intervals that cover several days and online views of the last stored data. The contribution will explain the challenges and the advantages induced by this kind of data access methods. Existing and planned solutions for Wendelstein 7-X will be depicted. Particularly the "Data Browser" -a graphical tool specially designed to fulfil these tasks at W7-X -will be presented.