9.7. Scalable Collectives Plans

Plans and measurements for the DVM-wide collectives — restructuring grpcomm around operations rather than components, and the record of what the lateral-movement experiment built, measured, and why it was withdrawn.

• 9.7.1. Restructuring the DVM collectives around operations
  • 9.7.1.1. Context
  • 9.7.1.2. Status
  • 9.7.1.3. The operations
  • 9.7.1.4. Cost model
  • 9.7.1.5. Design
  • 9.7.1.6. What the numbers turned out to be
  • 9.7.1.7. What a client actually asks about a remote peer
  • 9.7.1.8. What Slurm’s PMI2 does, and what it tells us
  • 9.7.1.9. Reassessing the allgather, after the reset
  • 9.7.1.10. Verification
  • 9.7.1.11. Open questions
• 9.7.2. Two trees: a low-radix release beside the high-radix rollup
  • 9.7.2.1. Status
  • 9.7.2.2. Why this one first
  • 9.7.2.3. The decision that shapes everything else
  • 9.7.2.4. Shape
  • 9.7.2.5. Deriving the second tree
  • 9.7.2.6. Fault model
  • 9.7.2.7. Selection
  • 9.7.2.8. First measurement, and what it does not settle
  • 9.7.2.9. Verification
  • 9.7.2.10. Open questions