12f.1 MPI and Grid Computing UNC-Wilmington, C. Ferner, 2008 Nov 4, 2008

12f.2 MPICH-G2 MPICH is an implementation of the standard MPI MPICH-G is an implementation of MPI that uses the Globus Toolkit MPICH-G2 is a complete redesign and reimplementation of MPICH-G

12f.3 MPICH-G2 MPICH-G2 hides heterogeneity by using the Globus Toolkit for –authentication –authorization –exectutable staing –process control –communication –redirection of standard input and output –remote file access

12f.4 % grid-proxy-init % mpirun -np 6 myprog mpirun globusrun DUROC GRAM CondorforkSGE MDS GASS P0P1P2P3P4P5 Generates RSL Submits multiple jobs Authenticates, Coordinates Startup Initiates Job, Detects Termination Process Control

12f.5 RSL mpirun will generate the RSL or one can create/provide the RSL This is RSL version 1 (not XML)‏ + ( &(resourceManagerContact="m1.utech.edu") (count=10)‏ (jobtype=mpi)‏ (label="subjob 0")‏ (environment=(GLOBUS_DUROC_SUBJOB_INDEX 0))‏ (directory=/homes/users/smith)‏ (executable=/homes/users/smith/myapp)‏ )‏ ( &(resourceManagerContact="m2.utech.edu") (count=10)‏ (label="subjob 1")‏ (environment=(GLOBUS_DUROC_SUBJOB_INDEX 1))‏ (directory=/homes/users/smith)‏ (executable=/homes/users/smith/myapp)‏ )‏ ( &(resourceManagerContact="c1.nlab.gov") (count=10)‏ (jobtype=mpi)‏ (label="subjob 2")‏ (environment=(GLOBUS_DUROC_SUBJOB_INDEX 2))‏ (directory=/users/smith)‏ (executable=/users/smith/myapp)‏ )‏

12f.6 Topology Early implementations of MPI's collective communication operations assumed all processes were equidistant from on another. This assumption is unlikely in a Grid environment Shared-Memory Cluster Cluster 2 Site ASite B

12f.7 Topology Use the concept of Communicators, MPICH-G2 collective communication operations are topology-aware. It uses the concept of “levels” and “colors”