Casa Parallelization meeting minutes

Monday January 3rd Room 317, 3:30pm MDT

Attendees: Urvashi, Jim, James, Bryan, Brian, Jeff, Kumar, Sanjay

Targets/tasks for January 3rd - January 10th

• Continue code development of async I/O Jim
• Complete remaining timing scripts Greg at AAS
• Generate procedures and first timings for test cases James
• Time domain partitioning with multiple MSes per imaging process Kumar
• Examine timing of MS-MFS parallel clean

Discussion/Agenda

• Continue code development of async I/O Jim
  • working toward getting imager to make use of it
  • make aipsrc variable to control async vs sync I/O
• Complete remaining timing scripts Greg at AAS
  • Small spectral status (needed further cleaning)
    • does not include continuum subtraction as a separate timed step using uvconsub2.
  • Large continuum essentially done
  • Large spectral on hold
• Generate procedures and first timings for test cases James
  • Split seems much better
  • Tile size substantially affects performance, need to characterize behavior
  • Still need other data sets
• Time domain partitioning with multiple MSes per imaging process Kumar
  • Mention last week that cube case had regressed, is that real ?
  • Trying to identify 10% small reads, possibly metadata column (either main or sub table)
• Issues with image size and multiple threads. Urvashi
  • Some performance variance by image size
• Rob Reid in NM
  • Looking at split I/O characterstics
• Cluster scheduler scripting with CV James on hold for scripts
  • Discuss with Jim semantics for cluster/CASA interaction
• Cluster resource definitions James/Jim on hold