Revision 15 as of 2010-06-15 13:07:37

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Contents

  1. Overview
  2. Using ICT
    1. Setting up the environment
    2. Compiling MPI applications with Intel MPI
    3. MPD daemons
    4. Tracing information
    5. Fine tuning
    6. Debugging

1. Overview

The Intel Cluster Toolkit is a collection of MPI related tools, which is helpful when debugging, fine tuning and analyzing large MPI applications. ICT includes:

2. Using ICT

Each of this parts and its use at the cluster environment in DESY Zeuthen is described next.

2.1. Setting up the environment

Intitialize the Intel compiler and Intel MPI environment: 

ini ic openmpi_intel

Initialize ICT environment: 

 source /opt/intel/itac/7.2.2.006/bin/itacvars.sh
 source /opt/intel/impi/3.2.2.006/bin/mpivars.sh
 source /opt/products/idb/11.0/bin/ia32/idbvars.sh
 export I_MPI_CC=/opt/products/bin/icc

 source /opt/products/bin/ifortvars.sh ia32
 source /opt/products/bin/iccvars.sh ia32
 export IDB_HOME=/opt/products/bin/

2.2. Compiling MPI applications with Intel MPI

Add  LDFLAGS     = -L$(VT_LIB_DIR) -lmpi $(VT_ADD_LIBS)  to the IMB Makefile.

2.3. MPD daemons

TODO: machines.LINUX file TODO: mpd.hosts

Start MPD daemons on all hosts in mpd.hosts file: 

# ./sshconnectivity.exp machines.LINUX
# mpdboot -n 8 --rsh=ssh -f ./mpd.hosts

2.4. Tracing information

Run an application for the trace analyzer: 

# export VT_LOGFILE_FORMAT=STF;
# export VT_PCTRACE=5;
# export VT_PROCESS="0:N ON";
# export VT_LOGFILE_PREFIX=IMB-MPI1_inst;
# rm -fr $VT_LOGFILE_PREFIX; mkdir $VT_LOGFILE_PREFIX;
# mpiexec -n 2 itcpin --run -- ./IMB-MPI1 -npmin 2 PingPong;
# traceanalyzer ./IMB-MPI1_inst/IMB-MPI1.stf &;

After you are done with running and analysing your application shut down the MPD daemons with the command: 

# mpdallexit

2.5. Fine tuning

Invoke mpitune: 

# mpitune -f machines.LINUX -o ./ --app mpiexec -genv MPIEXEC_DEBUG 1 -n 2 ./IMB-MPI1 -np 2 PingPong
# mpiexec -tune app.conf -n 4 ./IMB-MPI1 -np 2 PingPong

2.6. Debugging

Start execution of the MPI program in debugging mode on 8 nodes each running 2 processes: 

# mpiexec -idb -genv MPIEXEC_DEBUG 1 -n 8 ./IMB-MPI1 -np 2 PingPong