We calibrate the M100 Band 3 Science Verification dataset, using an edited version of the python script alma-m100-analysis-hpc-regression.py, which is included in the (parallelized) CASA tarballs. For purposes of comparison, we do initial tests on rtdc7.

General Notes:

1. CASA has two parallelization modes depending on the version:
   
   • Old Parallel (OP) Framework>, which makes use of an external cluster configuration file (deprecated in CASA 4.5.0).
     
   • Message Passing Interface (MPI) Framework (implemented in CASA 4.3.0).
2. The following python scripts were used:
           m100-casa44-tarball-script.py (CASA 4.4.0).
           m100-pre-casa44-tarball-script.py (pre-CASA 4.4.0).
3. The scripts were executed with the commands:
           m100-casa44-tarball-script.sh. (CASA 4.4.0, uses MPI framework).
           m100-pre-casa44-tarball-script.sh. (pre-CASA 4.4.0, uses OP framework).
4. Steps 0-18 constitute the calibration.
5. All interactive lines have been removed to enable comparison with hydra batch jobs.
6. References to ALMA Science Data Model (ASDM) format files have also been removed, since they are not readily available. Before running the script, we rename:

   mv X54.ms X54-monolith.ms

   mv X220.ms X220-monolith.ms

7. We remove the directories (CASA 4.4.0 and later only):

   \rm -r X54.ms.flagversions

   \rm -r X220.ms.flagversions

CASA 4.7.2 (and previous versions) appear to have no real parallelism capabilities. Changing the number of engines (CPUs) makes negligible difference to the execution time. The dominant factor is the I/O speed of the disk. Running CASA on an NFS mounted disk will take approximately 5 times longer than a local disk.

CASA 4.7.2 (release date: 3/23/2017)

1. Tests on 0-4 were run while the machine was as already busy w/ an other job.
2. ssd means it was running off a local SSD disk.
3. rtdc7 n=7 local & rtdc8 n=3 were done while other jobs were running.
4. By far the most important factor is the I/O speed of the disk (e.g. local v mounted)
5. The difference between rtdc7 and rtdc9 is RAM (rtdc7=48GB/rtdc9=132GB). Both have 3.5GHz CPUs.

All tests run with seven engines unless otherwise stated.

CASA 4.4.0 (release date: 6/22/2015)

1. We run these tests using the MPI framework (see general notes above).
2. The hydra tests were run post-upgrade (September, 2015).

1. The CASA 4.3.0 release notes claim:
       "CASA has a new MPI parallelization framework and is currently testing use cases."
   We use the OP Framework here (see general notes above), since the MPI Framework is still in the early stages of testing.
2. The first three hydra tests employed 7 engines, the last one 14 engines.
3. The first two hydra tests ran without any memory specification, the last two ran with mem=8192.
4. The hydra tests were run pre-upgrade (May, 2015).

1. The test fails due to a bug in the software. For details, consult:
           The CASA 4.2.0 report
2. Tests were not attempted on hydra.

1. The RTDC machine, rglinux12, was run for comparison.
2. The hydra tests were run on a single dedicated machine (compute-0-32.local) as sole user. Any other means of running resulted in far poorer results.
3. For details about the test and results, consult:
           The CASA 4.1.0 report .