Evaluation of the ITER data archiving network API on the DIII-D tokamak

The systems responsible for the archival and access of data at ITER will play a critical role from the very start of tokamak operations. Ensuring the readiness of the software being developed to handle the large amounts of data to be streamed to the archive systems will be of great importance and require extensive testing. To assist in this validation DIII-D offers the flexibility and means for testing on an operational tokamak. Because of the extensive experience gained in supporting data archiving and retrieval for a large and varied set of diagnostics and in-house expertise in Linux based systems, DIII-D is able to provide a uniquely qualified test platform to fully exercise ITER's software. In this paper, we report on the work that was recently performed to setup a data acquisition and archiving test system connected to live diagnostics for the purpose of evaluating the performance and completeness of the ITER Data Archiving Network Application Program Interface (DAN API). Diagnostic data that was made available and examined for archiving into the ITER DAN included data such as plasma current, bolometry, electron density, soft x-ray signals, visible camera images, data from the Thomson scattering and Electron Cyclotron Heating (ECH) systems. The hardware used for the test system was comprised of two high performing archiver computers and two data acquisition streamer computers. The archiver nodes were configured with 64 GB of RAM and 1 TB of fast solid state drive storage, and networked to the acquisition computers in a local 10 Gb/s network. This configuration was chosen in order to push performance limits and test data streaming and archiving to the ITER DAN at rates of up to 1 Gb/s from multiple archive sources.