What’s New in Work Queue Michael Albrecht, University of Notre Dame CCL Workshop, June 2012
Overview New “Batch Job” Systems Work Queue Enhancements Moab / Cluster MPI Queue Work Queue Enhancements Hierarchical Work Queue
Batch Job Systems Abstraction Layer Library for generic task submission Used by Makeflow
Moab & other Clusters Similar to “SGE” Explicitly support Moab scheduler Support other, similar schedulers Set name, submit and remove commands moab
MPI Queue Workflow W W W W W W W W W W W W W W
MPI Queue Workflow W W W W F W W W W W
MPI Queue Enables arbitrary computation on “MPI-only” clusters Ranks 1-N talk to Rank 0, which acts as a “foreman” Assumes shared parallel filesystem for cluster API very similar to Work Queue Fully supported by Batch Job/Makeflow
Work Queue
Work Queue is Wonderful Easily harness 100’s-1000’s of cores Combine multiple resources for one project Dynamically scale computational resources Private Cluster Campus Condor Pool Public Cloud Provider Shared SGE Makefile Makeflow Local Files and Programs sge_submit_workers W ssh Wv condor_submit_workers Hundreds of Workers in a Personal Cloud submit tasks
Work Queue has Limits Bandwidth, file size, and computation length constrain potential number of workers
Work Queue has Limits T0 ??? T1 T2 T3 T4 W1 W2 W3 W4 W5 T5 Natural parallelism of a workflow leaves extra workers idle
Work Queue has Limits Synchronous transfer leaves network resources idle, increases dispatch time
“…except for the problem of too many layers of indirection” Add more indirection! “All problems in computer science can be solved by another layer of indirection” -David Wheeler “…except for the problem of too many layers of indirection” Kevlin Henney
Hierarchical Work Queue Master (Makeflow) Worker Worker Worker Worker Worker Worker Worker Worker
Hierarchical Work Queue Master (Makeflow) Foreman Foreman Worker Worker Worker Worker Worker Worker Worker Worker
Hierarchical Work Queue Master (Makeflow) Shared FS Foreman Foreman Worker Worker Worker Worker Worker Worker Worker Worker
Hierarchical Work Queue Master (Makeflow) Shared FS Shared FS Foreman Foreman Worker Worker Worker Worker Worker Worker Worker Worker
Hierarchical Work Queue Master (Makeflow) Shared FS Foreman Foreman Shared FS Shared FS Foreman Foreman Worker Worker Worker Worker Worker Worker Worker Worker
Hierarchical Work Queue Coming Soon! http://www.nd.edu/~ccl 19