BNL Home

User Guide for NY Blue/L

Please note, New York Blue/L has been decommissioned and these web pages have not yet been updated to reflect its removal from service. The New York Blue/P is now one rack and remains in service. The BNL Blue Gene/Q also remains in service.

Simple Example: Compile, Link, Run


This user guide documents topics of interest to the end users of NY Blue such as using the compilers, interactive and batch job submission, and applications support.

Local and some offsite documentation can be found in the sidebar at the left.

Blue Gene is not a typical parallel computer. It is meant for codes that scale well into hundreds or even thousands of processors. The processors in Blue Gene are slower than those on the BNL Linux clusters. So, unless your code scales well and so can benefit from using a lot of processors, you may be better off running it with fewer processors on e.g. a standard Linux cluster.

The compute nodes on which your job runs are rebooted prior to running your job on them, ensuring that there is no "junk" remaining from whatever jobs ran on those nodes previously. The nodes are also exclusively allocated to your job.

To run on NY Blue, you must submit your job to the LoadLeveler batch system.

If you find any errors on these pages please notify NY Blue Web Administrator

Top of Page

Simple Example: Compile, Link, Run

  1. Copy the source code for a C language "Hello World" MPI program to any test subdirectory of your home directory:
    cp /bgl/samplecodes/c/hello.c /home/johndoe/tests/c/
  2. cd /home/johndoe/tests/c
  3. Compile and Link:
    mpixlc -o helloc.exe hello.c
  4. Create a LoadLeveler batch file example.ll, specifying in it the number of compute nodes to be used for your job, and submit it to LoadLeveler:
    llsubmit example.ll  
  5. The output and (if any) error files 3236.out and 3236.err respectively appear in /home/johndoe/tests/c when the job has completed  
  6. This is only a quick example, see the instructions for running LoadLeveler batch jobs.  

Example Description: The batch job submission example above uses the mpich wrapper mpixlc for the IBM C cross compiler to create an executable for the compute nodes, then submits a LoadLeveler batch job to run that executable on the NY Blue compute nodes.

Top of Page