test_coord_write_remote_atomic.py
python
sha256:81ae324db5ad375fbfe4834c6fcb378312cafad3cc92dec5d3e5c427306621a2
fix: remove commit_exists filter from have anchors — server…
Sonnet 4.6
patch
21 days ago
| 1 | """ |
| 2 | Tests for the bug: _write_remote_records uses write_text() which truncates |
| 3 | the target file to 0 bytes before writing. Any concurrent reader between the |
| 4 | truncation and write completion sees either 0 bytes or partial/corrupt content. |
| 5 | |
| 6 | Root cause (coord_sync.py::_write_remote_records, last line): |
| 7 | |
| 8 | target.write_text(f"{json.dumps(rec)} |
| 9 | ", encoding="utf-8") |
| 10 | |
| 11 | write_text() opens with mode 'w', which truncates to 0 bytes immediately. |
| 12 | The write then fills the file. Between truncation and final close() there is |
| 13 | a window where the file is partially written or empty. |
| 14 | |
| 15 | The fix: use write_text_atomic() which writes to a mkstemp temp file and then |
| 16 | os.rename()s into place. rename() is atomic on POSIX — readers always see |
| 17 | either the old content or the complete new content, never 0 bytes. |
| 18 | |
| 19 | write_text_atomic is already imported in coord_sync.py and used throughout |
| 20 | the codebase for exactly this purpose. |
| 21 | |
| 22 | Coverage: |
| 23 | Unit — _write_remote_records produces valid files post-write |
| 24 | Concurrency — concurrent writers never leave 0-byte or invalid-JSON files |
| 25 | Data integrity — written content exactly matches the source record |
| 26 | Idempotency — overwriting same record_id produces correct final state |
| 27 | Security — path validation still enforced after atomicity fix |
| 28 | Performance — atomic write is not dramatically slower than write_text |
| 29 | Regression — all existing _write_remote_records security tests still pass |
| 30 | """ |
| 31 | from __future__ import annotations |
| 32 | |
| 33 | import json |
| 34 | import pathlib |
| 35 | import threading |
| 36 | import time |
| 37 | from unittest.mock import patch |
| 38 | |
| 39 | import pytest |
| 40 | |
| 41 | from muse.core.types import MsgpackDict |
| 42 | from muse.core.paths import coordination_dir, muse_dir |
| 43 | |
| 44 | # --------------------------------------------------------------------------- |
| 45 | # Helpers |
| 46 | # --------------------------------------------------------------------------- |
| 47 | |
| 48 | _ALL_KINDS = ("reservation", "intent", "release", "heartbeat", "dependency", "task", "claim") |
| 49 | _FUTURE_TS = "2099-12-31T23:59:59+00:00" |
| 50 | |
| 51 | |
| 52 | def _make_repo(tmp_path: pathlib.Path) -> pathlib.Path: |
| 53 | muse_dir(tmp_path).mkdir(parents=True, exist_ok=True) |
| 54 | return tmp_path |
| 55 | |
| 56 | |
| 57 | def _record(kind: str, record_id: str, payload_size: int = 64) -> MsgpackDict: |
| 58 | return { |
| 59 | "kind": kind, |
| 60 | "record_id": record_id, |
| 61 | "run_id": "run-torvalds", |
| 62 | "payload": {"data": "k" * payload_size}, |
| 63 | "expires_at": _FUTURE_TS, |
| 64 | } |
| 65 | |
| 66 | |
| 67 | def _remote_path(root: pathlib.Path, kind: str, record_id: str) -> pathlib.Path: |
| 68 | return coordination_dir(root) / "remote" / kind / f"{record_id}.json" |
| 69 | |
| 70 | |
| 71 | def _write_remote(root: pathlib.Path, records: list[dict]) -> None: |
| 72 | from muse.cli.commands.coord_sync import _write_remote_records |
| 73 | _write_remote_records(root, records) |
| 74 | |
| 75 | |
| 76 | # ============================================================================= |
| 77 | # 1. UNIT — basic correctness after write |
| 78 | # ============================================================================= |
| 79 | |
| 80 | class TestWriteRemoteUnit: |
| 81 | |
| 82 | def test_written_file_is_valid_json(self, tmp_path: pathlib.Path) -> None: |
| 83 | root = _make_repo(tmp_path) |
| 84 | rec = _record("reservation", "res-000001") |
| 85 | _write_remote(root, [rec]) |
| 86 | path = _remote_path(root, "reservation", "res-000001") |
| 87 | assert path.exists() |
| 88 | data = json.loads(path.read_text()) |
| 89 | assert data["kind"] == "reservation" |
| 90 | assert data["record_id"] == "res-000001" |
| 91 | |
| 92 | def test_written_file_content_exactly_matches_record(self, tmp_path: pathlib.Path) -> None: |
| 93 | root = _make_repo(tmp_path) |
| 94 | rec = _record("task", "task-abc123", payload_size=256) |
| 95 | _write_remote(root, [rec]) |
| 96 | path = _remote_path(root, "task", "task-abc123") |
| 97 | data = json.loads(path.read_text()) |
| 98 | assert data == rec |
| 99 | |
| 100 | def test_file_is_never_empty_after_write(self, tmp_path: pathlib.Path) -> None: |
| 101 | root = _make_repo(tmp_path) |
| 102 | for i in range(20): |
| 103 | rec = _record("heartbeat", f"hb-{i:04d}") |
| 104 | _write_remote(root, [rec]) |
| 105 | path = _remote_path(root, "heartbeat", f"hb-{i:04d}") |
| 106 | content = path.read_text() |
| 107 | assert content, f"file {path} is empty after write" |
| 108 | |
| 109 | def test_overwrite_produces_new_content(self, tmp_path: pathlib.Path) -> None: |
| 110 | root = _make_repo(tmp_path) |
| 111 | rec_v1 = _record("claim", "claim-001") |
| 112 | rec_v1["payload"] = {"version": 1} |
| 113 | _write_remote(root, [rec_v1]) |
| 114 | |
| 115 | rec_v2 = _record("claim", "claim-001") |
| 116 | rec_v2["payload"] = {"version": 2} |
| 117 | _write_remote(root, [rec_v2]) |
| 118 | |
| 119 | path = _remote_path(root, "claim", "claim-001") |
| 120 | data = json.loads(path.read_text()) |
| 121 | assert data["payload"]["version"] == 2 |
| 122 | |
| 123 | def test_all_seven_kinds_written_correctly(self, tmp_path: pathlib.Path) -> None: |
| 124 | root = _make_repo(tmp_path) |
| 125 | records = [_record(kind, f"{kind}-001") for kind in _ALL_KINDS] |
| 126 | _write_remote(root, records) |
| 127 | for kind in _ALL_KINDS: |
| 128 | path = _remote_path(root, kind, f"{kind}-001") |
| 129 | assert path.exists(), f"{kind} file not written" |
| 130 | data = json.loads(path.read_text()) |
| 131 | assert data["kind"] == kind |
| 132 | |
| 133 | |
| 134 | # ============================================================================= |
| 135 | # 2. CONCURRENCY — concurrent writers must never produce 0-byte or corrupt files |
| 136 | # ============================================================================= |
| 137 | |
| 138 | class TestWriteRemoteConcurrency: |
| 139 | """ |
| 140 | These tests FAIL before the fix (write_text) and PASS after (write_text_atomic). |
| 141 | |
| 142 | The bug: write_text opens with 'w' which truncates to 0 bytes before writing. |
| 143 | Between truncation and close(), concurrent readers see empty or partial files. |
| 144 | """ |
| 145 | |
| 146 | def test_concurrent_writes_same_record_id_no_zero_byte_reads(self, tmp_path: pathlib.Path) -> None: |
| 147 | """ |
| 148 | Writer thread: overwrites the same file 500 times. |
| 149 | Reader thread: reads the file concurrently, checks for 0-byte or corrupt reads. |
| 150 | """ |
| 151 | root = _make_repo(tmp_path) |
| 152 | rec = _record("reservation", "res-concurrent", payload_size=4096) |
| 153 | # Prime the file |
| 154 | _write_remote(root, [rec]) |
| 155 | |
| 156 | target = _remote_path(root, "reservation", "res-concurrent") |
| 157 | zero_byte_reads: list[int] = [] |
| 158 | corrupt_reads: list[str] = [] |
| 159 | stop = threading.Event() |
| 160 | |
| 161 | def writer() -> None: |
| 162 | for _ in range(500): |
| 163 | _write_remote(root, [rec]) |
| 164 | |
| 165 | def reader() -> None: |
| 166 | iteration = 0 |
| 167 | while not stop.is_set(): |
| 168 | try: |
| 169 | content = target.read_text() |
| 170 | if not content.strip(): |
| 171 | zero_byte_reads.append(iteration) |
| 172 | else: |
| 173 | json.loads(content) |
| 174 | except json.JSONDecodeError as exc: |
| 175 | corrupt_reads.append(str(exc)) |
| 176 | except FileNotFoundError: |
| 177 | pass # transient — rename may briefly make old name disappear |
| 178 | iteration += 1 |
| 179 | |
| 180 | t_writer = threading.Thread(target=writer) |
| 181 | t_reader = threading.Thread(target=reader) |
| 182 | t_reader.start() |
| 183 | t_writer.start() |
| 184 | t_writer.join() |
| 185 | stop.set() |
| 186 | t_reader.join() |
| 187 | |
| 188 | assert zero_byte_reads == [], ( |
| 189 | f"Saw {len(zero_byte_reads)} zero-byte reads — write_text truncation window exposed.\n" |
| 190 | f"First occurrence at reader iteration {zero_byte_reads[0]}.\n" |
| 191 | f"Fix: use write_text_atomic() instead of write_text()." |
| 192 | ) |
| 193 | assert corrupt_reads == [], ( |
| 194 | f"Saw {len(corrupt_reads)} corrupt-JSON reads — torn write occurred.\n" |
| 195 | f"First error: {corrupt_reads[0]}" |
| 196 | ) |
| 197 | |
| 198 | def test_concurrent_writes_different_record_ids_all_valid(self, tmp_path: pathlib.Path) -> None: |
| 199 | """ |
| 200 | 8 threads each writing their own record_id 100 times. |
| 201 | All files must be valid JSON after all threads complete. |
| 202 | """ |
| 203 | root = _make_repo(tmp_path) |
| 204 | n_threads = 8 |
| 205 | n_writes = 100 |
| 206 | |
| 207 | def worker(idx: int) -> None: |
| 208 | rec = _record("intent", f"intent-{idx:04d}", payload_size=2048) |
| 209 | for _ in range(n_writes): |
| 210 | _write_remote(root, [rec]) |
| 211 | |
| 212 | threads = [threading.Thread(target=worker, args=(i,)) for i in range(n_threads)] |
| 213 | for t in threads: |
| 214 | t.start() |
| 215 | for t in threads: |
| 216 | t.join() |
| 217 | |
| 218 | # All files must be valid JSON |
| 219 | for i in range(n_threads): |
| 220 | path = _remote_path(root, "intent", f"intent-{i:04d}") |
| 221 | assert path.exists(), f"intent-{i:04d}.json missing" |
| 222 | content = path.read_text() |
| 223 | assert content, f"intent-{i:04d}.json is empty" |
| 224 | data = json.loads(content) |
| 225 | assert data["record_id"] == f"intent-{i:04d}" |
| 226 | |
| 227 | def test_concurrent_pull_and_read_no_corruption(self, tmp_path: pathlib.Path) -> None: |
| 228 | """ |
| 229 | Simulates two concurrent coord sync pull operations writing to the same remote dir. |
| 230 | Both pull the same record. Reader checks consistency throughout. |
| 231 | """ |
| 232 | root = _make_repo(tmp_path) |
| 233 | rec = _record("release", "rel-kernel-6-14", payload_size=8192) |
| 234 | _write_remote(root, [rec]) # prime |
| 235 | |
| 236 | target = _remote_path(root, "release", "rel-kernel-6-14") |
| 237 | errors: list[str] = [] |
| 238 | stop = threading.Event() |
| 239 | |
| 240 | def puller() -> None: |
| 241 | for _ in range(300): |
| 242 | _write_remote(root, [rec]) |
| 243 | |
| 244 | def reader() -> None: |
| 245 | while not stop.is_set(): |
| 246 | try: |
| 247 | content = target.read_text() |
| 248 | if not content.strip(): |
| 249 | errors.append("zero-byte file read") |
| 250 | else: |
| 251 | json.loads(content) |
| 252 | except json.JSONDecodeError as exc: |
| 253 | errors.append(f"corrupt JSON: {exc}") |
| 254 | except FileNotFoundError: |
| 255 | pass |
| 256 | |
| 257 | t1 = threading.Thread(target=puller) |
| 258 | t2 = threading.Thread(target=puller) |
| 259 | t_reader = threading.Thread(target=reader) |
| 260 | |
| 261 | t_reader.start() |
| 262 | t1.start() |
| 263 | t2.start() |
| 264 | t1.join() |
| 265 | t2.join() |
| 266 | stop.set() |
| 267 | t_reader.join() |
| 268 | |
| 269 | assert errors == [], ( |
| 270 | f"{len(errors)} corruption events during concurrent pull simulation.\n" |
| 271 | f"First: {errors[0]}" |
| 272 | ) |
| 273 | |
| 274 | |
| 275 | # ============================================================================= |
| 276 | # 3. DATA INTEGRITY — written content survives overwrite correctly |
| 277 | # ============================================================================= |
| 278 | |
| 279 | class TestWriteRemoteDataIntegrity: |
| 280 | |
| 281 | def test_large_payload_written_completely(self, tmp_path: pathlib.Path) -> None: |
| 282 | """50KB payload must be written and read back completely.""" |
| 283 | root = _make_repo(tmp_path) |
| 284 | rec = _record("dependency", "dep-kernel-mm", payload_size=50 * 1024) |
| 285 | _write_remote(root, [rec]) |
| 286 | |
| 287 | path = _remote_path(root, "dependency", "dep-kernel-mm") |
| 288 | data = json.loads(path.read_text()) |
| 289 | assert len(data["payload"]["data"]) == 50 * 1024 |
| 290 | |
| 291 | def test_sequential_overwrites_produce_correct_final_state(self, tmp_path: pathlib.Path) -> None: |
| 292 | """100 sequential overwrites of the same record_id — final content is correct.""" |
| 293 | root = _make_repo(tmp_path) |
| 294 | for version in range(100): |
| 295 | rec = _record("reservation", "res-overwrite") |
| 296 | rec["payload"]["version"] = version |
| 297 | _write_remote(root, [rec]) |
| 298 | |
| 299 | path = _remote_path(root, "reservation", "res-overwrite") |
| 300 | data = json.loads(path.read_text()) |
| 301 | assert data["payload"]["version"] == 99 |
| 302 | |
| 303 | def test_batch_write_all_files_present(self, tmp_path: pathlib.Path) -> None: |
| 304 | """Writing 1000 records in one call — all files must be present and valid.""" |
| 305 | root = _make_repo(tmp_path) |
| 306 | records = [ |
| 307 | _record(_ALL_KINDS[i % len(_ALL_KINDS)], f"rec-{i:06d}") |
| 308 | for i in range(1000) |
| 309 | ] |
| 310 | _write_remote(root, records) |
| 311 | |
| 312 | for i, rec in enumerate(records): |
| 313 | path = _remote_path(root, rec["kind"], f"rec-{i:06d}") |
| 314 | assert path.exists(), f"rec-{i:06d} missing" |
| 315 | data = json.loads(path.read_text()) |
| 316 | assert data["record_id"] == f"rec-{i:06d}" |
| 317 | |
| 318 | def test_file_never_partially_written_single_thread(self, tmp_path: pathlib.Path) -> None: |
| 319 | """Single-threaded: read immediately after each write must be complete.""" |
| 320 | root = _make_repo(tmp_path) |
| 321 | for i in range(50): |
| 322 | rec = _record("task", "task-sequential", payload_size=1024 * (i % 10 + 1)) |
| 323 | _write_remote(root, [rec]) |
| 324 | path = _remote_path(root, "task", "task-sequential") |
| 325 | content = path.read_text() |
| 326 | assert content, f"empty file after write {i}" |
| 327 | data = json.loads(content) |
| 328 | assert data == rec, f"content mismatch at write {i}" |
| 329 | |
| 330 | |
| 331 | # ============================================================================= |
| 332 | # 4. SECURITY — path validation still enforced (regression) |
| 333 | # ============================================================================= |
| 334 | |
| 335 | class TestWriteRemoteSecurity: |
| 336 | """Verify the fix doesn't break existing security validation.""" |
| 337 | |
| 338 | def test_unknown_kind_rejected(self, tmp_path: pathlib.Path) -> None: |
| 339 | root = _make_repo(tmp_path) |
| 340 | rec = {"kind": "../traversal", "record_id": "safe-id", "payload": {}} |
| 341 | _write_remote(root, [rec]) |
| 342 | malicious_path = coordination_dir(root) / "remote" / ".." / "traversal" / "safe-id.json" |
| 343 | assert not malicious_path.resolve().exists(), "path traversal via kind succeeded" |
| 344 | |
| 345 | def test_unsafe_record_id_rejected(self, tmp_path: pathlib.Path) -> None: |
| 346 | root = _make_repo(tmp_path) |
| 347 | rec = {"kind": "reservation", "record_id": "../../../etc/passwd", "payload": {}} |
| 348 | _write_remote(root, [rec]) |
| 349 | malicious = coordination_dir(root) / "remote" / "reservation" / "../../../etc/passwd.json" |
| 350 | assert not pathlib.Path("/etc/passwd.json").exists() or True # sanity |
| 351 | # The file must not be written outside the remote/ dir |
| 352 | remote_dir = coordination_dir(root) / "remote" |
| 353 | written = list(remote_dir.rglob("*.json")) if remote_dir.exists() else [] |
| 354 | assert written == [], f"unsafe record_id produced files: {written}" |
| 355 | |
| 356 | def test_null_byte_record_id_rejected(self, tmp_path: pathlib.Path) -> None: |
| 357 | root = _make_repo(tmp_path) |
| 358 | rec = {"kind": "reservation", "record_id": "valid\x00malicious", "payload": {}} |
| 359 | _write_remote(root, [rec]) |
| 360 | remote_dir = coordination_dir(root) / "remote" |
| 361 | written = list(remote_dir.rglob("*.json")) if remote_dir.exists() else [] |
| 362 | assert written == [], f"null-byte record_id produced files: {written}" |
| 363 | |
| 364 | def test_valid_records_still_written_after_invalid_ones_skipped(self, tmp_path: pathlib.Path) -> None: |
| 365 | root = _make_repo(tmp_path) |
| 366 | records = [ |
| 367 | {"kind": "../traversal", "record_id": "id-1", "payload": {}}, # bad kind |
| 368 | _record("reservation", "res-valid-001"), # good |
| 369 | {"kind": "reservation", "record_id": "../bad", "payload": {}}, # bad record_id |
| 370 | _record("task", "task-valid-001"), # good |
| 371 | ] |
| 372 | _write_remote(root, records) |
| 373 | |
| 374 | assert _remote_path(root, "reservation", "res-valid-001").exists() |
| 375 | assert _remote_path(root, "task", "task-valid-001").exists() |
| 376 | # Only 2 valid files |
| 377 | remote_dir = coordination_dir(root) / "remote" |
| 378 | written = list(remote_dir.rglob("*.json")) |
| 379 | assert len(written) == 2 |
| 380 | |
| 381 | |
| 382 | # ============================================================================= |
| 383 | # 5. PERFORMANCE — atomic write is not dramatically slower than write_text |
| 384 | # ============================================================================= |
| 385 | |
| 386 | class TestWriteRemotePerformance: |
| 387 | |
| 388 | def test_500_records_completes_under_3s(self, tmp_path: pathlib.Path) -> None: |
| 389 | root = _make_repo(tmp_path) |
| 390 | records = [ |
| 391 | _record(_ALL_KINDS[i % len(_ALL_KINDS)], f"perf-{i:06d}", payload_size=512) |
| 392 | for i in range(500) |
| 393 | ] |
| 394 | t0 = time.monotonic() |
| 395 | _write_remote(root, records) |
| 396 | elapsed = time.monotonic() - t0 |
| 397 | assert elapsed < 3.0, f"500 atomic writes took {elapsed:.3f}s (> 3s)" |
| 398 | |
| 399 | def test_atomic_write_throughput_records_per_second(self, tmp_path: pathlib.Path) -> None: |
| 400 | root = _make_repo(tmp_path) |
| 401 | records = [_record("reservation", f"tput-{i:06d}") for i in range(200)] |
| 402 | |
| 403 | t0 = time.monotonic() |
| 404 | _write_remote(root, records) |
| 405 | elapsed = time.monotonic() - t0 |
| 406 | |
| 407 | rps = 200 / elapsed if elapsed > 0 else float("inf") |
| 408 | assert rps >= 50, f"write_remote throughput {rps:.0f} rec/s is below minimum 50/s" |
File History
4 commits
sha256:81ae324db5ad375fbfe4834c6fcb378312cafad3cc92dec5d3e5c427306621a2
fix: remove commit_exists filter from have anchors — server…
Sonnet 4.6
patch
21 days ago
sha256:36c3cb3e76619d4c30a6d9bf81b5ec4ff148e30dcfed913e3114ca7b43b81c7e
fix: rename objects→blobs in push client and all stale test…
Sonnet 4.6
patch
22 days ago
sha256:c06a9b9b9fee26c68ea725b44d54b2c0a171301ce9de746d5b656617b4463a9a
fix: repair four test failures from post-migration audit
Sonnet 4.6
patch
28 days ago
sha256:1900655993c83c4107067375548a7be823e471d2515830842f1a12cba4bd3cdf
fix: unified object store migration — idempotent writes, JS…
Sonnet 4.6
minor
⚠
29 days ago