1 / 14

MPI support in gLite

MPI support in gLite. Enol Fernández CSIC. MPI on the Grid. CREAM/WMS. Submission/Allocation Definition of job characteristics Search and select adequate resources Allocate (or coallocate ) resources for the job Execution File distribution Batch system interaction

gaye
Download Presentation

MPI support in gLite

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MPI support in gLite Enol Fernández CSIC

  2. MPI on the Grid CREAM/WMS • Submission/Allocation • Definition of job characteristics • Search and select adequate resources • Allocate (or coallocate) resources for the job • Execution • File distribution • Batch system interaction • MPI implementation details MPI-Start

  3. Allocation / Submission • Process count specified with the CPUNumber attribute Type = "Job"; CPUNumber = 23; Executable = "my_app"; Arguments = "-n 356 -p 4"; StdOutput = "std.out"; StdError = "std.err"; InputSandBox = {"my_app"}; OutputSandBox = {"std.out", "std.err"}; Requirements = Member("OPENMPI”, other.GlueHostApplicationSoftwareRunTimeEnvironment);

  4. MPI-Start • Specify a unique interface to the upper layer to run a MPI job • Allow the support of new MPI implementations without modifications in the Grid middleware • Support of “simple” file distribution • Provide some support for the user to help manage his data GridMiddleware MPI-START MPI Resources

  5. MPI-Start Design Goals • Portable • The program must be able to run under any supported operating system • Modular and extensible architecture • Plugin/Component architecture • Relocatable • Must be independent of absolute path, to adapt to different site configurations • Remote “injection” of mpi-start along with the job • “Remote” debugging features

  6. MPI-Start Architecture CORE Scheduler Execution Hooks Local User Compiler File Dist. Open MPI MPICH2 LAM PACX PBS/Torque SGE LSF

  7. Using MPI-Start (I) JobType = "Normal"; CpuNumber = 4; Executable = "starter.sh"; InputSandbox = {"starter.sh”} StdOutput = "std.out"; StdError = "std.err"; OutputSandbox = {"std.out","std.err"}; Requirements = Member("MPI-START”, other.GlueHostApplicationSoftwareRunTimeEnvironment) && Member("OPENMPI”, other.GlueHostApplicationSoftwareRunTimeEnvironment); $ catstarter.sh #!/bin/sh # Thisis a script tocallmpi-start # Setenvironmentvariablesneeded export I2G_MPI_APPLICATION=/bin/hostname export I2G_MPI_APPLICATION_ARGS= exportI2G_MPI_TYPE=openmpi export I2G_MPI_PRECOMMAND=time # Execute mpi-start $I2G_MPI_START stdout: Scientific Linux CERN SLC release 4.5 (Beryllium) Scientific Linux CERN SLC release 4.5 (Beryllium) lflip30.lip.pt lflip31.lip.pt stderr: real 0m0.731s user 0m0.021s sys 0m0.013s

  8. … CpuNumber = 4; Executable = ”mpi-start-wrapper.sh"; Arguments = “userapp OPENMPIsomeappargs…” InputSandbox = {”mpi-start-wrapper.sh”}; Environment = {“I2G_MPI_START_VERBOSE=1”, …} ... Using MPI-Start (II) #!/bin/bash MY_EXECUTABLE=$1 shift MPI_FLAVOR=$1 shift export I2G_MPI_APPLICATION_ARGS=$* # Convertflavortolowercaseforpassingtompi-start. MPI_FLAVOR_LOWER=`echo $MPI_FLAVOR | tr '[:upper:]' '[:lower:]'` # Pull out thecorrectpathsfortherequestedflavor. evalMPI_PATH=`printenv MPI_${MPI_FLAVOR}_PATH` # Ensuretheprefixiscorrectly set. Don'trelyonthedefaults. eval I2G_${MPI_FLAVOR}_PREFIX=$MPI_PATH export I2G_${MPI_FLAVOR}_PREFIX # Setupformpi-start. export I2G_MPI_APPLICATION=$MY_EXECUTABLE exportI2G_MPI_TYPE=$MPI_FLAVOR_LOWER # Invokempi-start. $I2G_MPI_START

  9. MPI-Start Hooks (I) • File Distribution Methods • Copy files needed for execution using the most appropriate method (shared filesystem, scp, mpiexec, …) • Compiler flag checking • checks correctness of compiler flags for 32/64 bits, changes them accordingly • User hooks: • build applications • data staging

  10. MPI-Start Hooks (II) #!/bin/sh pre_run_hook () { # Compile theprogram. echo "Compiling ${I2G_MPI_APPLICATION}" # Actually compile theprogram. cmd="mpicc ${MPI_MPICC_OPTS} -o ${I2G_MPI_APPLICATION} ${I2G_MPI_APPLICATION}.c" $cmd if [ ! $? -eq 0 ]; then echo "Error compilingprogram. Exiting..." exit 1 fi # Everything's OK. echo "Successfullycompiled ${I2G_MPI_APPLICATION}" return 0 } … InputSandbox = {…, “myhooks.sh”…}; Environment = {…, “I2G_MPI_PRE_HOOK=myhooks.sh”}; …

  11. MPI-Start: more features • Remote injection • Mpi-start can be sent along with the job • Just unpack, set environment and go! • Interactivity • A pre-command can be used to “control” the mpirun call • $I2G_MPI_PRECOMMAND mpirun …. • This command can: • Redirect I/O • Redirect network traffic • Perform accounting • Debugging • 3 different debugging levels: • VERBOSE: basic information • DEBUG: internal flow information • TRACE: set –x at the beginning. Full trace of the execution

  12. Future work (I) • New JDL description for parallel jobs (proposed by the EGEE MPI TF): • WholeNodes (True/False): • whether or not full nodes should be reserved • NodeNumber (default = 1): • number of nodes requested • SMPGranularity (default = 1): • minimum number of cores per node • CPUNumber (default = 1): • number of job slots (processes/cores) to use • CREAM team working on how to support them

  13. Future work (II) • Management of non MPI jobs • new execution environments (OpenMP) • generic parallel job support • Support for new schedulers • Condor and SLURM support • Explore support for new architectures: • FPGAs, GPUs,…

  14. More Info… • gLite MPI PT: • https://twiki.cern.ch/twiki/bin/view/EMI/GLiteMPI • MPI-Start trac • http://devel.ifca.es/mpi-start • contains user, admin and developer docs • MPI Wiki @ TCD • http://www.grid.ie/mpi/wiki

More Related