Maxwell : Photon Science Resources

The DESY Photon Science department provides dedicated resources for internal and external academic users. This page briefly describes the resources and their intended use.

Remote Login / Interactive login nodes

max-fs-display.desy.de is the best entry point to the Maxwell Cluster for all academic users (inhouse & external) of PETRA III and FLASH/FLASH2.

max-fs-display establishes resource access through a load balancer and can be reached from inside as well as directly from outside DESY in the folllowing ways:

• by web-browser under https://max-fs-display.desy.de:3389
• Using the FastX3 client. A brief introduction and links to download pages can be found here.
• via ssh using an ssh-client of your choice (e.g. putty). There is no need for ssh-tunnels or deviations via bastion.

Terms of Use

The nodes behind max-fs-display are shared by quite a number of users and thus actions carries out by one user affects others being logged into same node . To make work reasonably pleasant you should keep a few rules in mind.

• Use max-fs-display for graphical work, developments and undemanding computational work.
• You can use max-fs-display as job submission node
• Don't use max-fs-display for computations requiring lots of memory or cpu power.

Usage of resources is monitored. You will receive notifications when exceeding a sensible use of resources. Continuously ignoring the emails might lead to forceful termination of applications. If you have a need for substantial computational resources, please use batch jobs to submit jobs into Maxwell cluster (which can be interactive as well). Have a look at getting starting and running jobs for details. If you have any questions don't hesitate to contact us: maxwell.service@desy.de.

Feel free to also use https://max-display.desy.de:3443/, please note that those nodes are usually much more crowded, so max-fs-display is almost always the better choice. The same rules apply to max-display as for max-fs-display.

Computational Resources

Batch compute nodes are arranged in so called partitions. Using the partitions requires corresponding access rights. For PS partitions these can only be granted by FS-EC.

For DESY Photon Science staff:

• use the ps partition for CPU jobs or jobs requiring single GPU (i.e. P100). Use constraints to select specific hardware.
• use the psgpu partition for jobs requiring multiple GPUs.
• you might get access to maxwell and maxgpu partitions if your applications demand for it. Please drop a message to maxwell.service@desy.de if you need access to those partitions.

For external users:

• use the psx partition for CPU jobs or jobs requiring single GPU. Set constraints accordingly.

All Maxwell users can also use the all or allgpu partitions, but be aware that your jobs might be terminated by jobs in higher priority partitions.

To determine which and how much compute resources you can use (see useful commands for more details):

• my-partitions - tells you which partitions you are entitled to use
• max-limits - tells how much and for how long

All Maxwell users can also use the Maxwell jupyterhub. Have a look at the jupyterhub description for more details.

Compute nodes are available for all academic visiting Photons Science users of PETRA III or FLASH/FLASH2 and staff members for which EC is in charge of at any time not limited to beamtimes. If you're lacking access to resources please get in touch with FS-EC or as an external users ask the beamline staff.

During beamtime dedicated resources might have been allocated during the experiment. Please get in touch with FS-EC or ask the beamline staff. 

Support

fs-ec@desy.de: for access to partitions, experiment specific questions or problems.

maxwell.service@desy.de: for questions or problems about compute resource, applications, batch jobs and anything maxwell specific.

Acknowledgment

Acknowledging the use of the Maxwell cluster is greatly appreciated and helps funding the resources. See Maxwell Documentation for details.