Jan Meyer sent email on April 13, 2021 presenting a need for updating the auto-processing; mainly speed-up, because of the faster and bigger Eiger detector. A possible template from EDNA/MaxIV exists.
Johanna Hakanpaeae emailed on April 21, 2021; expresses urgency to the matter of severe processing lag between data taking and result; users start complain that it negatively impacts the beamline experiments.
(Missing: Vijay Kartik)
Auto-processing on little cluster at beamline used to work fine, but new detector exceeds the capabilities to process results in time.
Results are crucial in case of short test scans to generate scan parameters for full scan.
Shifting to Maxwell computation is not straightforward (rights, users).
Current cluster runs "XDS" pipeline, timing is about "10s data taking is followed by ~8min processing";
more precisely: certain scans take about 2min to complete and are run in succession, processing takes 4 times longer, thus creating a back log with increasing lag to obtain the processing results.
The expectation is that more and more powerful compute nodes will solve the problem. Two additional nodes have already been acquired and are present in the Maxwell cluster.
Template for such a solution exists at MAX IV, but some obstacles are present. Namely:
The detector, as well as the used software is fixed; the only available solution is to increase the resources for processing.
Sergey Yakubov proposes to use a special beamtime user that grants access to the beamline file system from Maxwell during the duration of the beamtime (i.e. after start_beamtime, before stop_beamtime).
[[ Note: usually only the core file system is accessible from the compute nodes of the Maxwell cluster ]]
The implementation of the solution has to be done in collaboration with IT, since it is governed by the configuration of the Maxwell cluster and the access to the file systems.
Identified steps are:
Frank Schluenzen raised the issue that in the case of several groups sharing a beamtime (e.g. BAG proposal), the access and accounting is also shared.
Vijay Kartik has implemented a similar (but not identical) workflow for P10 and could help with identifying the different issues involved and outlining the needed steps.
Sergey Yakubov has agreed to help with the implementation of identified missing requirements on the side of Maxwell.
Jan Meyer and Johanna Hakanpaeae will review the progress and success.