Complementary Capability Computing on HPCx Dr Alan Gray

212 th November 2008HPCx User Group Meeting HPCx and HECToR: complementary services

312 th November 2008HPCx User Group Meeting Complementary capability computing Complementary services provide a unique opportunity to maximise the benefits for UK research –HECToR is our leading HPC facility –HPCx is our "National Supercomputer", trading overall utilisation in favour of a more flexible servic The main principles behind providing complementary services are: –to maximise the combined research benefits of HECToR and HPCx for the UK HPC user community; –to ensure that the most appropriate service is chosen for the scientific research to be conducted.

412 th November 2008HPCx User Group Meeting HPCx: a more flexible service HPCx’s operation has been modified to provide a more flexible service –We have adapted policies and enabled new features and functionalities HPCx can handle more unusual jobs –e.g. jobs that cannot easily or readily be accommodated on HECToR Certain job classes have adverse impact on overall utilisation on prime national service –but can be accommodated on a complementary service HPCx users have helped to guide these changes –We visited all consortia with >= 1M AUs remaining

512 th November 2008HPCx User Group Meeting HPCx flexibility

612 th November 2008HPCx User Group Meeting Flexible Policies Very long jobs –HPCx now has 48 hour queues, requests for longer jobs will also be considered Interactive and responsive computing –HPCx now has short high priority 20 minute debug queues –HPCx can now accommodate more flexible access patterns, for example to exploit grid technologies

712 th November 2008HPCx User Group Meeting New Features and Functionality Advanced reservation –HPCx now supports the Highly Available Robust Co- scheduler (HARC) –Allows users to reserve processors for a particular time in the future –Relevant for meta-computing, computational steering and on-line visualisation –You may just wish to reserve a series of processors one afternoon

812 th November 2008HPCx User Group Meeting New Features and Functionality Ensembles of jobs –We have developed functionality which allows multiple independent jobs to be easily submitted from the same job script to run simultaneously Visualisation –Paraview parallel visualisation tool now installed Computational steering –We are working directly with consortia to enable this for their specific cases

912 th November 2008HPCx User Group Meeting Additional flexibility Shared memory –A cluster of fat shared-memory nodes each with several processors under the control of a single operating system –Advantageous for applications that exploit shared memory parallelism and for users with large memory jobs –Accessing the full memory Under populating the node Shared memory segments and shared memory parallelism

1012 th November 2008HPCx User Group Meeting Additional flexibility Large memory jobs –Phase 4 upgrade of HPCx –Two of the IBM 575+ servers will have 128 GB of memory Data intensive jobs –HPCx has a significant tape store –Ideally suited for users with a need to archive large amounts of data to tape for local processing

1112 th November 2008HPCx User Group Meeting How to exploit HPCx’s new flexibility For the remainder of HPCx, we will (in addition to running the helpdesk) focus our additional support on Complementarity –In particular we will support the new CCC projects in any way we can Please get in touch with the helpdesk with –questions –suggestions or requests –requirements that cannot easily be met within the current operational policies of HECToR and HPCx –feedback Guidelines on Complementarity are available at: –