f. HPCG & IOR metrics

In this section you will run the High Performance Conjugate Gradients (HPCG) Benchmark used to represent the computational intensity of a broad range of applications. Then you will run the IOR benchmark commonly used to evaluate storage performances on a system. The intent of this section is not to demonstrate the performances you can obtain on your system but visualize metrics for both applications. If you are interested in running IOR on Lustre with FSx for Lustre you will want to look at the Storage Lab

Install HPCG

  1. First download and compile HPCG:

    wget https://aws-hpc-workshops.s3.amazonaws.com/install_grafana_benchmarks.sh
    bash install_grafana_benchmarks.sh
  2. Next, create a submit file. You run over 8 nodes with a single core on each node. This establishes your baseline run:

    cat > hpcg.sbatch << EOF
    #!/bin/bash
    #SBATCH --job-name=hpcg-job
    #SBATCH --nodes=8
    #SBATCH --output=hpcg-run.out
    
    module load openmpi/4.0.3
    mpirun --report-bindings --map-by core ${HOME}/hpcg/bin/xhpcg --nx 128 --ny 128 --nz 128 --rt 200
    EOF
  3. Submit the job and monitor the queue:

    sbatch hpcg.sbatch
    squeue -i 2
  4. Once the job submitted it will be placed in a configuring state, noted CF in the squeue output. After a couple of minutes, the job will change to a running state, noted R. HPCG Submit

  5. After the job completes, the HPCG output is stored in the HPCG-Benchmark_3.1_2020-[date].txt file that contains the timing information, scroll to the bottom and you’ll see:

    Final Summary::HPCG result is VALID with a GFLOP/s rating of=9.48102
    Final Summary::HPCG 2.4 rating for historical reasons is=9.75306
    Final Summary::Reference version of ComputeDotProduct used=Performance results are most likely suboptimal
    Final Summary::Reference version of ComputeSPMV used=Performance results are most likely suboptimal
    Final Summary::Reference version of ComputeMG used=Performance results are most likely suboptimal
    Final Summary::Reference version of ComputeWAXPBY used=Performance results are most likely suboptimal
    Final Summary::Results are valid but execution time (sec) is=160.038
    Final Summary::Official results execution time (sec) must be at least=1800

What are your observations when running HPCG? Look at the CPU usage, memory consumption and network throughput. Did you take a look at a particular instance?

Test with IOR

In the previous script we installed both IOR and HPCG. You will run both at the same time and see what the metrics tell you.

  1. Start by creating submission script to run IOR:

    cd $HOME
    cat > ior.sbatch << EOF
    #!/bin/bash
    #SBATCH --job-name=ior-job
    #SBATCH --nodes=8
    #SBATCH --output=ior-run.out
    
    module load intelmpi
    mpirun /shared/ior/bin/ior -w -r -o=/shared/test_dir -b=256m -a=POSIX -i=5 -F -z -t=64m -C
    EOF
  2. Then your job to run IOR

    sbatch ior.sbatch
    sbatch hpcg.sbatch
    squeue -i 2
  3. After HPCG completes take a look at the timing file HPCG-Benchmark_3.1_2020-[date].txt:

    Final Summary::Reference version of ComputeDotProduct used=Performance results are most likely suboptimal
    Final Summary::Reference version of ComputeSPMV used=Performance results are most likely suboptimal
    Final Summary::Reference version of ComputeMG used=Performance results are most likely suboptimal
    Final Summary::Reference version of ComputeWAXPBY used=Performance results are most likely suboptimal
    Final Summary::Results are valid but execution time (sec) is=156.78
    Final Summary::Official results execution time (sec) must be at least=1800
  4. What did you notice about the performance of both benchmarks? Take a look at the Compute Node Details dashboard and you will see IOR stressed the network with spikes looking like. IOR Network

  5. But did not stress the CPU: IOR CPU

  6. Now if you take a look at the metrics when you ran HPCG alone, you will observe a more of a constant load on the network with less spikiness. IOR Network

Did you take a look at the numbers of file descriptors opened when running IOR?