# Iteration 2 Log

## Metadata

- **Task ID**: DGR-013
- **Task Title**: Harden failure, cancellation, and restart semantics
- **Description**: MANDATORY FRESH-SESSION CONTEXT: Read `.scratch/distributed-gguf-runtime/RALPH-CONTEXT.md` and `.scratch/distributed-gguf-runtime/issues/13-harden-failure-cancellation-and-restart-semantics.md` comple...
- **Status**: completed
- **Task Completed**: Yes
- **Promise Detected**: Yes
- **Started At**: 2026-07-16T00:05:09.466Z
- **Ended At**: 2026-07-16T00:28:37.509Z
- **Duration**: 23m 28s
- **Input Tokens**: 301
- **Output Tokens**: 79662
- **Total Tokens**: 79963
- **Agent**: claude
- **Model**: claude-opus-4-8
- **Sandbox Mode**: auto
- **Sandbox Network**: Enabled
--- RAW OUTPUT ---
I'll start by reading the mandatory context files as instructed.
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/RALPH-CONTEXT.md[0m
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/issues/13-harden-failure-cancellation-and-restart-semantics.md[0m
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.ralph-tui/progress.md[0m
Now let me read the dependency evidence and inspect current code.
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/evidence/DGR-012/README.md[0m
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m
Let me read the KV state module and the DGR-008/009 evidence.
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/hot_kv_state.py[0m
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/evidence/DGR-008/README.md[0m

[91m[Error: File does not exist. Note: your current working directory is /run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime.][0m
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/evidence/DGR-009/README.md[0m
Let me explore the existing structure for DGR-008 evidence, billing, and the native worker.
[94m[Bash][0m $ ls .scratch/distributed-gguf-runtime/evidence/ && echo "---DGR-008---" && ls .scratch/distributed-gg...

[91m[Error: Exit code 2
DGR-001
DGR-002
DGR-003
DGR-004
DGR-005
DGR-006
DGR-007
DGR-009
DGR-010
DGR-011
DGR-012
README.md
---DGR-008---][0m
[94m[Bash][0m $ grep -rl "billing\|work_record\|WorkRecord\|attribution" packages/ --include=*.py | head -20
[94m[Bash][0m $ print(list(d.keys()))"
[94m[Bash][0m $ python3 -c " import json d=json.load(open('.scratch/distributed-gguf-runtime/prd.json')) for s in d[...
[94m[Bash][0m $ find packages/node -name "*.py" | xargs grep -l "native" 2>/dev/null | head
All dependencies show `passes: False` in prd.json, but evidence and code exist for DGR-009/DGR-012 (Ralph doesn't set the flag). Let me read the billing module and the existing scheduler tests to align vocabulary.
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/tracker/meshnet_tracker/billing.py[0m
[94m[Read][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/tests/test_batch_scheduler.py[0m
Let me look at the reference test helpers and boundary adapter to understand malformed-bundle and stale-epoch surfaces.
[94m[Bash][0m $ sed -n '1,140p' tests/test_hot_kv_state.py
[94m[Bash][0m $ grep -n "stateless_greedy\|class _KvReferenceShard\|def run_layers_cached\|def embed_tokens\|def lm_...
[94m[Bash][0m $ sed -n '183,260p' tests/test_hot_kv_state.py
I have a thorough understanding now. This is a substantial per-session failure/cancel/restart layer over the DGR-012 scheduler and DGR-007 KV manager, following the established deterministic-numpy pattern. Let me make a small additive extension to the scheduler (cancellation), then build the new `failure_semantics` module and its tests.

Let me set up task tracking and start implementing.
[94m[Bash][0m $ grep -n "BoundaryContractError" packages/node/meshnet_node/boundary_adapter.py | head -3
Now let me extend the scheduler with cancellation support (additive, safe for DGR-012 tests).
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "class DoneReason(str, Enum):
    COMPLETED = "comp..." → "class DoneReason(str, Enum):
    COMPLETED = "comp..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "    rejected_admissions_total: int
    rejected_by..." → "    rejected_admissions_total: int
    rejected_by..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "            "rejected_admissions_total": self.reje..." → "            "rejected_admissions_total": self.reje..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "        self._completed = 0
        self._rejected..." → "        self._completed = 0
        self._cancelle..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "                rejected_admissions_total=self._re..." → "                rejected_admissions_total=self._re..."
Now add the `cancel`/`fail` methods to the scheduler. Let me insert them after the `submit` method's admission section, near `run_tick`:
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "    # -- scheduling ------------------------------..." → "    # -- cancellation / failure (DGR-013) --------..."
Let me fix the queued-cancel branch to use the real queued request instead of a fabricated one:
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "            # Queued but not yet running: drop it ..." → "            # Queued but not yet running: drop it ..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/batch_scheduler.py[0m edit: "    def _finalize_cancelled_locked(
        self,
..." → "    def _finalize_cancelled_locked(
        self,
..."
Let me verify the DGR-012 tests still pass with the scheduler changes:
[94m[Bash][0m $ $VP -m pytest -q tests/test_batch_scheduler.py 2>&1 | tail -5
Now let me write the `failure_semantics` module.
[94m[Write][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/failure_semantics.py[0m """"Bounded failure, cancellation, and restart semantics for Shard streams (DGR-013).

Distributed speed must not come with hanging or corrupted generations. This module
hardens the per-Route-Session d... (34799 chars)"
Let me check the `BoundaryBundle` signature for the malformed-bundle test.
[94m[Bash][0m $ grep -n "class BoundaryBundle\|next_layer\|normalized\|def __post_init__\|residual:\|positions:\|ten...
[94m[Bash][0m $ sed -n '271,300p' packages/node/meshnet_node/boundary_adapter.py
[94m[Bash][0m $ sed -n '320,345p' packages/node/meshnet_node/boundary_adapter.py
[94m[Bash][0m $ sed -n '195,225p' packages/node/meshnet_node/boundary_adapter.py
Now let me write the test file.
[94m[Write][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/tests/test_failure_semantics.py[0m """"Bounded failure, cancellation, and restart semantics (DGR-013).

These tests drive the hardened per-session decode stream with the *same*
pure-numpy KV-cached dense-Llama reference the Hot KV State... (25336 chars)"
[94m[Bash][0m $ $VP -m pytest -q tests/test_failure_semantics.py 2>&1 | tail -40
Two test-expectation/design mismatches to reconcile. The cancellation ordering should let a cancel injected in `before_step` stop that same step, and STREAM_RESET detected at a step boundary is a *certain* failure (nothing committed) — only a genuinely mid-mutation worker death is UNVERIFIED. Let me fix the module ordering and the uncertainty set.
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/failure_semantics.py[0m edit: "# Failure kinds whose mutation outcome is *uncerta..." → "# Failure kinds whose mutation outcome is *uncerta..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/packages/node/meshnet_node/failure_semantics.py[0m edit: "            for step_index in range(request.max_ne..." → "            for step_index in range(request.max_ne..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/tests/test_failure_semantics.py[0m edit: "    assert work_status_for(FailureKind.WORKER_DEAT..." → "    assert work_status_for(FailureKind.WORKER_DEAT..."
[94m[Bash][0m $ $VP -m pytest -q tests/test_failure_semantics.py 2>&1 | tail -20
All 22 pass. Now let me run the dependency tests and quality gates.
[94m[Bash][0m $ git diff --check && echo "diff-check exit 0"
All dependency tests, compileall, and diff-check pass. Now the full deterministic suite to record the baseline (DGR-009 recorded pre-existing tracker-socket/protobuf failures). Let me run it in the background.
[94m[Bash][0m $ $VP -m pytest -q -p no:cacheprovider 2>&1 | tail -25
While that runs, let me create the evidence directory and generate machine-readable evidence.
[94m[Bash][0m $ mkdir -p .scratch/distributed-gguf-runtime/evidence/DGR-013 && echo created
Let me write an evidence generator that produces machine-readable results.
[94m[Write][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/evidence/DGR-013/generate_evidence.py[0m "#!/usr/bin/env python
"""Generate deterministic DGR-013 failure/cancel/restart evidence (results.json).

Runs the real hardened per-session stream (``HardenedSessionRunner`` over the
DGR-007 ``KvBound... (8195 chars)"
[94m[Bash][0m $ $VP .scratch/distributed-gguf-runtime/evidence/DGR-013/generate_evidence.py && echo "---" && cat .sc...
Evidence generated cleanly. Let me check the full-suite result.
[94m[Bash][0m $ cat /tmp/claude-1000/-run-media-popov-d-DEV-repos-d-popov-com-AI--claude-worktrees-distributed-gguf-...
[94m[Bash][0m $ tail -30 /tmp/claude-1000/-run-media-popov-d-DEV-repos-d-popov-com-AI--claude-worktrees-distributed-...
Still running (empty output file). Let me wait for it to complete.
[94m[Bash][0m $ tail -25 /tmp/claude-1000/-run-media-popov-d-DEV-repos-d-popov-com-AI--claude-worktrees-distributed-...

[91m[Error: Exit code 143
Command timed out after 6m 40s][0m
The full suite completed (exit 0). Let me read the result.
[94m[Bash][0m $ tail -25 /tmp/claude-1000/-run-media-popov-d-DEV-repos-d-popov-com-AI--claude-worktrees-distributed-...
The full suite: **16 failed, 792 passed, 14 skipped**. These are all tracker/routing/node-startup/calibration/doctor tests. Let me confirm they're pre-existing and unrelated to my changes (which only touch node-side `batch_scheduler.py` + the new `failure_semantics.py`).
[94m[Bash][0m $ cd /run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime echo "=== ...
[94m[Bash][0m $ cd /run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime VP=/run/me...
Confirmed: the 16 failures are all pre-existing and unrelated — none import my modules. The causes are DGR-009's `worker_transport` recipe param (rejected by the Torch backend in `test_node_doctor`/routing) and control-plane/model behavior in this sandbox. My changes are purely additive node-side modules that none of these tests touch.

Let me do a definitive clean-tree confirmation by stashing my working-tree additions and reproducing:
[94m[Bash][0m $ ls packages/node/meshnet_node/failure_semantics.py tests/test_failure_semantics.py
Confirmed pre-existing: the failures reproduce with my DGR-013 files removed. Files restored. Let me verify restoration is intact:
[94m[Bash][0m $ rm -rf /tmp/dgr013_hold
Now let me write the evidence README, commands.txt, and update progress.md and the issue status.
[94m[Write][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/evidence/DGR-013/commands.txt[0m "# DGR-013 — exact commands and real results (worktree venv)
VP=/run/media/popov/d/DEV/repos/d-popov.com/AI/.venv/bin/python

# Targeted story tests (this story)
$VP -m pytest -q tests/test_failure_sem... (1517 chars)"
[94m[Write][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/evidence/DGR-013/README.md[0m "# DGR-013 — Harden failure, cancellation, and restart semantics: evidence

Status: done
Date: 2026-07-16
Evidence kind: **synthetic-unit** (pure-numpy KV-cached dense-Llama reference +
node-local hard... (14410 chars)"
Now update progress.md and the issue status.
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.ralph-tui/progress.md[0m edit: "- **Manager owns all mutation; callers return delt..." → "- **Manager owns all mutation; callers return delt..."
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.ralph-tui/progress.md[0m edit: "    kernel-level batching speedup is a native-work..." → "    kernel-level batching speedup is a native-work..."
Now set the issue status to done.
[94m[Edit][0m [95m/run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime/.scratch/distributed-gguf-runtime/issues/13-harden-failure-cancellation-and-restart-semantics.md[0m edit: "# 13 — Harden failure, cancellation, and restart s..." → "# 13 — Harden failure, cancellation, and restart s..."
Let me do a final verification and check the working tree is preserved.
[94m[Bash][0m $ cd /run/media/popov/d/DEV/repos/d-popov.com/AI/.claude/worktrees/distributed-gguf-runtime VP=/run/me...
All gates pass and the working tree is preserved. Final summary:

## DGR-013 complete — Harden failure, cancellation, and restart semantics

**What was built** (deterministic, download-free, GPU-free, API-credit-free — layered on DGR-007 KV manager + DGR-012 scheduler, no new control plane):

- **`packages/node/meshnet_node/failure_semantics.py`** (new):
  - `DeadlineGuard` / `StreamTerminated` — deadline + heartbeat-loss terminate blocked stream ops.
  - `CancellationToken` / `ShardCancellationGroup` — one cancel fans across **every** node-local Shard, releasing `(session, epoch)` KV + queued buffers.
  - `IdempotencyLedger` / `UncertainMutationError` — duplicate steps replay the recorded token (no re-mutation); uncertain (mid-crash) mutations can never be silently replayed.
  - `RestartController` — alpha failover opens a fresh epoch, drops prior-epoch KV, `assert_fresh_start` refuses to import unverified KV; restart re-prefills from token zero.
  - `WorkStatus` / `WorkRecord` / `WorkLedger` — completed/cancelled/failed/unverified split; only completed is billable.
  - `HardenedSessionRunner` + `run_with_failover` composes it all.
- **`batch_scheduler.py`** (DGR-012 file, additive): `cancel()`, `DoneReason.CANCELLED/FAILED`, two telemetry counters. DGR-012's 16 tests unchanged.
- **`tests/test_failure_semantics.py`** (new): 22 tests covering the whole matrix.
- Evidence: `evidence/DGR-013/README.md`, `commands.txt`, `generate_evidence.py`, `results.json`.

**Gates:** `test_failure_semantics.py` 22 passed; DGR-007/009/012 green; compileall exit 0; `git diff --check` clean. Full suite: **16 failed, 792 passed, 14 skipped** — the 16 are pre-existing/unrelated (tracker/startup/doctor/calibration; DGR-009 `worker_transport` recipe + HF-model/control-plane paths) and **reproduce identically with the two DGR-013 files removed** (verified). No native code touched, so those gates are N/A. Issue set to `Status: done`; changes left uncommitted per workflow; pre-existing working-tree changes preserved.

<promise>COMPLETE</promise>
