neuron-tai/.scratch/distributed-gguf-runtime/issues/12-implement-continuous-batching-and-bounded-admission.md

12 — Implement continuous batching and bounded admission

Status: ready-for-agent

Mandatory fresh-session context

• Read RALPH-CONTEXT.md completely before changing code.
• This issue is DGR-012 in prd.json.
• Read the evidence README for every dependency listed below.
• Inspect current code and git status; historical text and previous agent claims are not evidence.

Description

As a node operator, I need active sessions batched safely so that concurrency increases aggregate throughput rather than serializing every request.

Expected durable outputs

• Continuous batching/admission scheduler
• Concurrency 1/2/4/8 report
• Queue, batch and KV-pressure evidence
• evidence/DGR-012/README.md

Acceptance criteria

• Node scheduler admits sessions against weight, KV, scratch, and queue budgets.
• Compatible decode steps from multiple sessions form llama.cpp batches while preserving per-session positions and outputs.
• Prefill does not starve decode; scheduling policy and bounds are explicit.
• Backpressure prevents unbounded queued activations or KV growth.
• Capability telemetry reports active sessions, queue depth, batch occupancy, KV pressure, prefill/decode rates, and rejected admissions.
• Concurrency 1/2/4/8 benchmark identifies saturation and shows no cross-session corruption.
• Targeted pytest tests pass
• python -m compileall packages tests passes for Python changes
• git diff --check passes
• Default tests remain deterministic, model-download-free, API-credit-free, and GPU-free
• Full deterministic pytest -q passes, or the exact pre-existing unrelated failure is recorded with a clean-tree reproduction
• Pinned native C++ target builds and focused CTest/protocol tests pass where native code is touched
• llama.cpp patch stack applies cleanly to the exact pinned commit where patch code is touched
• Read .scratch/distributed-gguf-runtime/RALPH-CONTEXT.md and this story issue completely before changing code
• Read and verify every dependency evidence README before relying on dependency behavior
• Preserve all pre-existing working-tree changes and stage only files belonging to this story
• Write .scratch/distributed-gguf-runtime/evidence/DGR-012/README.md with files changed, exact commands and real results, limitations, compatibility notes, and dependent-story handoff
• Update only this story issue to Status: done after every acceptance criterion and quality gate passes

Dependency handoff

• DGR-007 must have passes: true; read ../evidence/DGR-007/README.md and verify its referenced files/commands.
• DGR-009 must have passes: true; read ../evidence/DGR-009/README.md and verify its referenced files/commands.
• DGR-010 must have passes: true; read ../evidence/DGR-010/README.md and verify its referenced files/commands.

Finish contract

• Create the task evidence directory and durable handoff required above.
• Preserve real failures and blockers; never fabricate benchmark, model, test or hardware output.
• Change this issue to Status: done only after all criteria pass.
• Emit <promise>COMPLETE</promise> only after the evidence handoff exists.

References

• Ralph execution context
• PRD
• Implementation strategy
• Current architecture
• Architecture decision