Module performance Roadmap

Performance Module Roadmap

Current Status

Production performance runtime with comprehensive measurement, optimization strategy control, NUMA/cache tuning, and hardware-aware acceleration behavior. Complete Phase 1–6 delivery with contract frozen, error taxonomy defined, focused tests (PFM-01..16), benchmarks (GATE-PFM-01..06), and documentation aligned.

In Progress

Q1 2027 priorities

• re-baseline p95/p99 envelopes for core performance module operations (Target: Q1 2027)
• broaden benchmark depth for mixed and distributed performance scenarios (Target: Q1 2027)
• harden long-running reliability under sustained adaptive workload shifts (Target: Q1 2027)

Planned Features

Mid-term (6-12 months, Q2 2027+)

• distributed performance tracing integration (Target: Q2 2027)
• adaptive memory-pool resizing under NUMA topology awareness (Target: Q2 2027)

Completed Highlights (Q4 2026)

• Phase 2 feature hardening: optimization algorithm validation and hardware-aware adaptation
  • evidence: phase2_feature_flags hardware detection (x86/x64 CPUID, ARM NEON, storage); wisckey/dostoevsky/cicada/ligra/rabitq fail-closed validation; bounds checking on parameter spaces
• Phase 3 error handling standardization: unified diagnostics across adaptive/measurement/export subsystems
  • evidence: adaptive_batch_tuner config validation (min/max sizes, ema_alpha ∈ [0,1]); per_query_cost_model bounds (cpuCost, pageReadCost); consistent null-safety and exception paths
• hardening edge-case behavior across adaptive optimization and hardware fallback paths
  • evidence: test_cicada.cpp (14 deterministic GTest cases); test_performance_contract_hardening_focused.cpp (PFM-01..16)
• benchmark stabilization for performance module hot paths and scalability cases
  • evidence: benchmarks/performance/bench_performance_release_gates.cpp (GATE-PFM-01..06 with deterministic seeding kCanonicalSeed=42)
• diagnostics consistency for profiling/export/optimization incident classes
  • evidence: performance_api_contract.h error taxonomy (PERF_COMPILE_TIMEOUT..PERF_STATS_UNAVAILABLE); contract-hardening tests verify consistency

Completed Highlights (Q3 2026)

• API contract freeze: PerfError taxonomy, CacheStats, PoolAcquireResult, CostEstimate frozen v1.0
  • evidence: include/performance/performance_api_contract.h §Error Taxonomy
• error taxonomy definition: 7 standardized error codes (PERF_COMPILE_TIMEOUT..PERF_STATS_UNAVAILABLE)
  • evidence: include/performance/performance_api_contract.h## Implementation Phases

Phase 1: Design / API Contract

• freeze measurement/optimization/memory-hardware contracts for active major line (Target: Q3 2026)
  • evidence: include/performance/performance_api_contract.h — PerfError taxonomy, CacheStats, PoolAcquireResult, CostEstimate frozen v1.0
• define explicit error taxonomy for performance subsystem failures (Target: Q3 2026)
  • evidence: include/performance/performance_api_contract.h §Error Taxonomy (7 codes PERF_COMPILE_TIMEOUT..PERF_STATS_UNAVAILABLE)

Phase 2: Core Implementation

• complete hardening for optimization and profiling internals (Target: Q4 2026)
  • evidence: phase2_feature_flags.cpp hardware detection (CPUID, ARM NEON, storage); cicada/dostoevsky/ligra/rabitq/wisckey hardened with validation
• align feature gating and fallback behavior to bounded runtime contracts (Target: Q4 2026)
  • evidence: runtime detection syncs with compile-time flags (THEMIS_ENABLE_*); fail-closed on unsupported hardware; graceful diagnostics

Phase 3: Error Handling and Edge Cases

• standardize fail-safe behavior for unsupported hardware and invalid tuning inputs (Target: Q4 2026)
  • evidence: adaptive_batch_tuner config validation (min/max, ema_alpha ∈ [0,1]); per_query_cost_model bounds checking; throw on invalid
• unify diagnostics across measurement/export/optimization incidents (Target: Q4 2026)
  • evidence: consistent error propagation via exceptions; parameter validation gates; null-safety checks across all phase3 components

Phase 4: Tests

• expand focused regressions for optimization, cache, and NUMA edge scenarios (Target: Q4 2026)
  • evidence: tests/performance/test_performance_contract_hardening_focused.cpp — PFM-01..PFM-16 (16 deterministic GTest cases, kSeed=42)
• extend deterministic stress fixtures for high-throughput performance operations (Target: Q4 2026)
  • evidence: PFM-05..PFM-08 batch/arithmetic coverage in same file

Phase 5: Performance and Hardening

• lock benchmark-backed release gates for performance hot paths (Target: Q4 2026)
  • evidence: benchmarks/performance/bench_performance_release_gates.cpp — GATE-PFM-01..06
• validate p95/p99 and throughput behavior against release baselines (Target: Q4 2026)
  • evidence: GATE-PFM-01 (CacheStats ≤500ns p99), GATE-PFM-03 (error cast ≥50M ops/s)

Phase 6: Documentation and Acceptance

• core performance module docs aligned to source-verifiable behavior
• roadmap/future planning separated from historical changelog entries

Production Readiness Checklist

• core performance surfaces documented and source-verified
• module-level security and failure behavior documented
• benchmark mapping documented in performance expectations
• remaining hardening tasks closed for adaptive/memory/hardware edge paths
  • evidence: contract-hardening tests (PFM-01..16), cicada tests (14 cases), benchmark gates (GATE-PFM-01..06) all passing
• release benchmark stabilization complete
  • evidence: GATE-PFM-01..06 in benchmarks/performance/bench_performance_release_gates.cpp

Known Issues and Limitations

• runtime behavior depends on host hardware capabilities and enabled feature flags.
• selected adaptive and hardware-dependent edge scenarios need continued hardening.
• benchmark breadth should continue expanding for advanced distributed scenarios.

Breaking Changes

No breaking performance contract planned. Any contract-breaking change requires migration notes and changelog entry before merge.

Program Execution Model — Wave Context

This module is a contributing module in the program-level Wave A → B → C → D execution model. It does not own a primary wave deliverable but must remain release_critical-green throughout all waves and must deliver Wave D operability improvements in Q1 2027. See [[../../ROADMAP.md|ROADMAP]] for the full wave model and exit criteria.

Wave D Contribution for performance

• Deliver or validate distributed tracing, high-cardinality stress coverage, exporter reliability, and operator remediation hints as applicable to this module (Target: Q1 2027)
• Contribute to or validate long-duration soak test coverage for this module's primary paths (Target: Q1 2027)
• Ensure runbook coverage for operator-critical scenarios in this module (Target: Q1 2027)

Cross-Wave Requirements

• release_critical CI must remain green on develop throughout all waves (Target: ongoing)
• p95/p99 benchmarks must be refreshed on representative hardware before Wave D sign-off (Target: Q1 2027)
• No behavioral regression may be introduced into modules in Wave A/B/C scope from changes in this module.

Program-Level Success Criteria (contribution)

• This module's distributed/acceleration paths fail closed (Target: Q1 2027)
• Benchmark-backed p95/p99 baselines exist on representative hardware (Target: Q1 2027)
• Operator-critical paths have diagnostics, alerts, and runbooks (Target: Q1 2027)