Daily Bulletin Archive

Oct. 12, 2017

Cheyenne’s economy queue has been enabled for a limited time to encourage greater use of the system and to make users’ core-hour allocations go farther. Jobs using the economy queue are charged a discounted rate of 30% compared to the regular queue.

Jobs submitted to the regular and economy queues have the same priority due to the current PBS Pro configuration, so all are encouraged to use the economy queue while it is available. Its availability will be re-evaluated as Cheyenne’s usage increases.

Check your Systems Accounting Manager (SAM )reports regularly to keep an eye on core-hours charges.

Oct. 12, 2017

NCAR postdoctoral researcher Alessandro Fanfarillo will present “Myths and reality of communication/computation overlap in MPI applications” at 3 p.m. MDT on Thursday, October 12, in the Mesa Lab Main Seminar Room.

Overlapping communication with computation will be more important than ever on future exascale architectures, Fanfarillo says, because of high data transfer and synchronization costs and the need to scale applications on billions of cores. In this seminar, he will explain the communication/computation overlap in MPI in theory and practice with multiple examples involving non-blocking and one-sided MPI routines. His research focuses on how to exploit heterogeneous architectures (CPU+Accelerators) and Partitioned Global Address Space (PGAS) languages (coarray Fortran, in particular) for scientific purposes. He is also the lead developer of OpenCoarrays, the open-source library that implements the coarray support in the GNU Fortran compiler.

The seminar will be webcast here. See the UCAR Software Engineering Assembly site for more information.

Oct. 9, 2017

No Downtime: Yellowstone, Cheyenne, HPSS, Geyser_Caldera, GLADE

Oct. 6, 2017

CISL supercomputer users who would like assistance with visualizing their data can ask for help from staff experts. This service is available to researchers using specialized visualization applications on the Geyser or Caldera clusters.

Staff members have helped science teams produce visualizations featured in such venues as the PEARC17 Conference (Practice & Experience in Advanced Research Computing) Visualization Showcase, the Supercomputing Conference Visualization Showcase, American Geophysical Union and American Meteorological Society events, the SIGGRAPH Electronic Theatre, and many others.  

See Advanced visualization support to learn how to submit a request, what criteria must be met, and other details.

Oct. 3, 2017

Cheyenne: Downtime Tuesday, October 3, 8:00 am - 12:00 am

HPSS: Downtime Tuesday, October 3, 7:30 am - 9:30 am

No Downtime: Yellowstone, Geyser_Caldera, GLADE

Oct. 3, 2017

The Cheyenne cluster will be unavailable from 8 a.m. to midnight MDT on Tuesday, October 3, to allow CISL staff to perform maintenance on several critical system components.

A system reservation will be put in place on batch jobs Monday afternoon. Jobs submitted with specified job times that overlap the reservation period will remain on hold until the system is restored to service. Running jobs that have not finished when maintenance begins will be killed and will need to be resubmitted after the maintenance period.

Users will be informed via the CISL Notifier service when the systems are returned to production.

Sep. 27, 2017

Allinea Software will hold a free webinar on Thursday, October 5, dealing with memory-bound code in high-performance and scientific applications. Attendees will see how the right checks and ongoing tuning can improve software run-times and identify bottlenecks that can slow down applications.  Click here to register or to find out more.

Sep. 27, 2017

Acknowledging the support of NCAR and CISL computing when you publish research results helps ensure continued support from the National Science Foundation and other sources of funding for future high-performance computing (HPC) systems. It is also a requirement of receiving an allocation, as noted in your award letter.

The reporting requirements, how to cite your use of various systems, and recommended wording of acknowledgments can be found on this CISL web page. The content of citations and acknowledgments varies depending on the type of allocation that was awarded.

Sep. 27, 2017

CISL staff are recommending that users avoid the tar command’s -S and --sparse options for handling sparse files when creating an archive. A recently discovered data corruption issue resulting from use of those options can affect tarballs that users create and it also has corrupted some automated GLADE user home directory backups over the past several months. Snapshots have not been affected, so users who suspect some file corruption may be able to use those to recover files.

Users are encouraged to avoid using the -S or --sparse options until a fix is in place and to watch for a Notifier message announcing that the work is complete.

Sep. 18, 2017

CISL is now accepting requests from university-based researchers for large-scale allocations for the new 5.34-petaflops Cheyenne cluster; submissions are due September 18.

Large allocations on Cheyenne are those of more than 400,000 core-hours. CISL accepts requests from university researchers for these large-scale allocations every six months. For submission instructions and information regarding available resources, see the CISL HPC Allocations Panel (CHAP) page.

Please contact cislhelp@ucar.edu if you have any questions about this opportunity.