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Topology Optimizer Summary

Generated by tools/optimize_topology_gurobi.py.

Solver

  • Gurobi used: yes
  • Version: 13.0.1
  • Selected status: OPTIMAL
  • Runtime: 0.037083 seconds
  • Solution pool entries exported: 2
  • IIS generated: yes
  • Warm start: c=5, e=3
  • Indicator constraints: region-used indicator constraints exported in LP/MPS model
  • Tuning: skipped; bounded model solves directly in this environment

Profiles Run

Profile Family V T c e AWS share AWS CORE year-1 Budget fit
aws_core_only_bootless_baseline aws_core_only_bootless_baseline 6 4 2 0 1.000 $3,381.00 no
strict_two_thirds_aws_core aws_core_plus_edge 18 12 4 3 0.667 $3,381.00 no
core_liveness_strict aws_core_plus_edge 18 12 4 3 0.667 $3,381.00 no
one_aws_region_failure_strict aws_core_plus_edge 18 12 4 3 0.667 $3,381.00 no
balanced_day0 aws_core_plus_edge_plus_public_boot_sentry 18 12 4 3 0.667 $3,381.00 no
low_cost aws_core_plus_edge_plus_public_boot_sentry 9 6 1 3 0.333 $3,381.00 no
growth_flexible_contract aws_core_plus_edge_plus_public_boot_sentry 18 12 4 3 0.667 $3,381.00 no
ultra_low_cost_day0 ultra_low_cost_day0 18 12 4 3 0.667 $2,862.00 no

Selected Day-0

The selected launch family is aws_core_plus_edge_plus_public_boot_sentry with exactly 3 private AWS CORE validator nodes, 2 EDGE validator nodes, and 2 public keyless boot/sentry nodes.

  • V=18
  • T=12
  • c=4 validators per AWS CORE node
  • e=3 validators per EDGE node
  • AWS CORE share=0.667
  • AWS CORE year-1 cost=$3,381.00
  • Effective monthly AWS CORE cost=$281.75
  • AWS CORE budget fit=no

Why V/c/e Were Chosen

balanced_day0 requires one AWS Region outage, one EDGE outage, and both EDGE nodes offline to preserve finality. The smallest equalized c/e pair that keeps AWS CORE at exactly two-thirds of validators is c=4, e=3, so V=18 and T=12. This is lower cost than the c=5 warm-start while preserving CORE-only liveness.

Exact client-family equality under one EL/CL pair per validator host is not mathematically possible for c=4, e=3. The optimizer therefore selected minimal_family_deviation and reports the deviation instead of claiming exact equality.

Warm-Start c=5 Family

e V T AWS share CORE>=T Region loss Exact clients Budget fit Reasons
1 17 12 0.882 yes yes no no V_divisible_by_3, single_client_pair_exact_family_equality, aws_core_budget_fit
2 19 13 0.789 yes yes no no V_divisible_by_3, single_client_pair_exact_family_equality, aws_core_budget_fit
3 21 14 0.714 yes yes no no single_client_pair_exact_family_equality, aws_core_budget_fit
4 23 16 0.652 no yes no no V_divisible_by_3, core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
5 25 17 0.600 no yes no no V_divisible_by_3, core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
6 27 18 0.556 no yes no no core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
7 29 20 0.517 no yes no no V_divisible_by_3, core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
8 31 21 0.484 no yes no no V_divisible_by_3, core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
9 33 22 0.455 no yes no no core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
10 35 24 0.429 no yes no no V_divisible_by_3, core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
12 39 26 0.385 no yes no no core_liveness_C_ge_T, single_client_pair_exact_family_equality, aws_core_budget_fit
15 45 30 0.333 no yes yes no core_liveness_C_ge_T, aws_core_budget_fit

AWS Contract Result

The selected AWS contract minimizes year-1 AWS CORE cost after the hard topology constraints. The hard budget model is infeasible at $1,400.00; reports/gurobi_iis.ilp records the budget conflict when Gurobi proves infeasibility.

Accepted Day-0 Risks

  • AWS CORE year-1 budget infeasible for three 4-vCPU/16-GiB AWS CORE nodes: Selected AWS CORE cost is $3381.00 versus $1400.00 budget.
  • Complete AWS provider outage may fail finality and oracle/control-plane quorum: All trusted Day-0 CORE oracle sources live on AWS.
  • Client-family exact equality is mathematically infeasible with one client pair per validator node: Minimal deviation is 2.0 validators from the one-third target.
  • Small Day-0 validator set: V=18 is launch-sized rather than the future V=45 target.