fix model DL doe 4-th time

This commit is contained in:
Dobromir Popov
2026-07-06 22:38:57 +03:00
parent 4f007aeef9
commit 7e7682be47
4 changed files with 106 additions and 14 deletions

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@@ -0,0 +1,58 @@
# US-047 — Model-source race: visibility, sane timeouts, quiet tracker aborts
Status: in progress
Priority: High (follow-up to US-044/US-046; blocks usable LAN downloads)
## Context
Reported 2026-07-06 (Windows CPU node, 79.2 GB RAM, `--tracker
http://192.168.0.179:8080 --model Qwen3.6-35B-A3B`):
1. Startup prints `(auto-join unavailable: HTTP Error 503)` even though the
user explicitly named a model. The auto-join query (`/v1/network/assign`)
never sends the requested model, so a fresh tracker + a caller too small
for the *recommended* preset 503s (expected per US-046) — but the whole
auto-join step is pointless when the user already picked a model: the
`/v1/nodes/assign?model=…` call right after it succeeds (assigned layers
02 with tracker `model_sources`).
2. The tracker-vs-HuggingFace race then starts, but only HuggingFace shows
progress (hf tqdm bars). The tracker tar download prints nothing and
swallows every failure (`except Exception: return None`), so the node
*appears* to download only from slow HF; the user killed it. Tracker-side
log showed the tar stream reset mid-`archive.add` — with no way to tell
whether the client timed out or the user aborted.
3. `_download_model_source` inherits `peer_timeout` (2.0 s) as its urlopen
socket timeout. Any 2 s read stall during a multi-GB tar stream silently
kills the tracker source and leaves HF as the only contender.
4. Every client abort spams the tracker console with a full
`BrokenPipeError`/`ConnectionResetError` traceback from `socketserver`.
## Fix
1. `startup.py`: skip the network auto-join query entirely when a model was
explicitly requested (`model` set and not `"stub-model"`); path 3b
(`/v1/nodes/assign?model=…`) is the authoritative one there.
2. `downloader.py`: model-source downloads get their own timeout constant
(30 s socket timeout) instead of the 2 s peer-probe timeout. Peer shard
downloads keep 2 s — they run sequentially before the race, and a dead
peer must not hang startup for 30 s; the race is concurrent so a slow
source costs nothing.
3. `downloader.py`: progress + failure visibility for the race —
`_download_model_source` prints received bytes every 512 MB and prints
the exception when a source fails, so "downloads only from HF" can never
happen silently again.
4. Tracker `_handle_model_files_download`: catch
`BrokenPipeError`/`ConnectionResetError` around the tar stream and log a
single line instead of a traceback.
## Acceptance criteria
- [ ] Node started with an explicit `--model` never queries
`/v1/network/assign` and never prints `auto-join unavailable`.
- [ ] During the race, tracker-source progress lines appear alongside HF
tqdm output; a failing tracker source prints its exception.
- [ ] A ≥2 s read stall no longer aborts a tracker model-source download
(30 s socket timeout).
- [ ] Client disconnect during `/v1/model-files/download` logs one line on
the tracker, no traceback.
- [ ] `python -m pytest` passes from repo root.

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@@ -19,6 +19,11 @@ from typing import Any
_DEFAULT_CACHE = Path.home() / ".cache" / "meshnet" / "shards" _DEFAULT_CACHE = Path.home() / ".cache" / "meshnet" / "shards"
_PEER_TIMEOUT_SECONDS = 2.0 _PEER_TIMEOUT_SECONDS = 2.0
# Model-source tar streams are multi-GB; a short socket timeout must not kill
# them on a transient read stall. Peer probes keep the short timeout because
# they run sequentially before the race and may hit dead endpoints.
_MODEL_SOURCE_TIMEOUT_SECONDS = 30.0
_PROGRESS_INTERVAL_BYTES = 512 * 1024 * 1024
def compute_shard_checksum(shard_dir: Path) -> str: def compute_shard_checksum(shard_dir: Path) -> str:
@@ -111,6 +116,8 @@ def _download_model_source(
source: dict, source: dict,
shard_dir: Path, shard_dir: Path,
timeout: float, timeout: float,
progress: bool = False,
label: str = "model-source",
) -> Path | None: ) -> Path | None:
url = source.get("url") url = source.get("url")
if not isinstance(url, str) or not url: if not isinstance(url, str) or not url:
@@ -125,16 +132,26 @@ def _download_model_source(
extract_dir = tmp_root / "extract" extract_dir = tmp_root / "extract"
extract_dir.mkdir() extract_dir.mkdir()
try: try:
received = 0
next_report = _PROGRESS_INTERVAL_BYTES
with urllib.request.urlopen(url, timeout=timeout) as resp, archive_path.open("wb") as out: with urllib.request.urlopen(url, timeout=timeout) as resp, archive_path.open("wb") as out:
while True: while True:
chunk = resp.read(1024 * 1024) chunk = resp.read(1024 * 1024)
if not chunk: if not chunk:
break break
out.write(chunk) out.write(chunk)
received += len(chunk)
if progress and received >= next_report:
print(f" {label}: {received / 1e9:.1f} GB received ...", flush=True)
next_report += _PROGRESS_INTERVAL_BYTES
if progress:
print(f" {label}: transfer complete ({received / 1e9:.2f} GB), extracting ...", flush=True)
_safe_extract_shard(archive_path, extract_dir) _safe_extract_shard(archive_path, extract_dir)
shutil.move(str(extract_dir), str(shard_dir)) shutil.move(str(extract_dir), str(shard_dir))
return shard_dir return shard_dir
except Exception: except Exception as exc:
if progress:
print(f" {label}: download failed: {exc!r}", flush=True)
return None return None
@@ -178,7 +195,9 @@ def _download_from_fastest_source(
for index, source in enumerate(model_sources): for index, source in enumerate(model_sources):
label = str(source.get("type") or "model-source") label = str(source.get("type") or "model-source")
candidate = tmp_root / f"source-{index}" candidate = tmp_root / f"source-{index}"
jobs[pool.submit(_download_model_source, source, candidate, timeout)] = (label, candidate) jobs[pool.submit(
_download_model_source, source, candidate, timeout, progress, label,
)] = (label, candidate)
allow_patterns = _allow_patterns_from_sources(model_sources) allow_patterns = _allow_patterns_from_sources(model_sources)
hf_candidate = tmp_root / "huggingface" hf_candidate = tmp_root / "huggingface"
jobs[pool.submit(_download_huggingface_subset, hf_repo, cache_dir, hf_candidate, allow_patterns)] = ( jobs[pool.submit(_download_huggingface_subset, hf_repo, cache_dir, hf_candidate, allow_patterns)] = (
@@ -189,7 +208,9 @@ def _download_from_fastest_source(
label, candidate = jobs[future] label, candidate = jobs[future]
try: try:
result = future.result() result = future.result()
except Exception: except Exception as exc:
if progress:
print(f" {label}: download failed: {exc!r}", flush=True)
continue continue
if result is None: if result is None:
continue continue
@@ -324,7 +345,7 @@ def download_shard(
cache_dir=cache_dir, cache_dir=cache_dir,
shard_dir=shard_dir, shard_dir=shard_dir,
progress=progress, progress=progress,
timeout=peer_timeout, timeout=max(peer_timeout, _MODEL_SOURCE_TIMEOUT_SECONDS),
) )
if raced is not None: if raced is not None:
return raced[1] return raced[1]

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@@ -561,13 +561,19 @@ def run_startup(
raise ValueError("--shard-start / --shard-end require --model-id") raise ValueError("--shard-start / --shard-end require --model-id")
# 3a. Auto-join: query tracker for network-wide HF model assignment. # 3a. Auto-join: query tracker for network-wide HF model assignment.
print("Querying tracker for network assignment...", flush=True) # Skipped when the user explicitly requested a model — the shard-assignment
assign_qs = urllib.parse.urlencode({"device": device, "vram_mb": assignment_vram_mb, "ram_mb": ram_mb}) # query below (/v1/nodes/assign?model=…) is authoritative there, and a fresh
# tracker would otherwise print a scary 503 for the model-less auto-join.
net_assignment: dict = {} net_assignment: dict = {}
try: if model and model != "stub-model":
net_assignment = _get_json(f"{tracker_url}/v1/network/assign?{assign_qs}") print(f"Model {model!r} requested explicitly — skipping network auto-join.", flush=True)
except Exception as exc: else:
print(f" (auto-join unavailable: {exc})", flush=True) print("Querying tracker for network assignment...", flush=True)
assign_qs = urllib.parse.urlencode({"device": device, "vram_mb": assignment_vram_mb, "ram_mb": ram_mb})
try:
net_assignment = _get_json(f"{tracker_url}/v1/network/assign?{assign_qs}")
except Exception as exc:
print(f" (auto-join unavailable: {exc})", flush=True)
assigned_hf_repo: str | None = net_assignment.get("hf_repo") assigned_hf_repo: str | None = net_assignment.get("hf_repo")
_gap_found: bool = bool(net_assignment.get("gap_found", False)) _gap_found: bool = bool(net_assignment.get("gap_found", False))

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@@ -3879,10 +3879,17 @@ class _TrackerHandler(http.server.BaseHTTPRequestHandler):
self.send_header("Content-Type", "application/x-tar") self.send_header("Content-Type", "application/x-tar")
self.send_header("X-Meshnet-Model-Source", "tracker") self.send_header("X-Meshnet-Model-Source", "tracker")
self.end_headers() self.end_headers()
# dereference: HF cache snapshots are symlinks into blobs/ — ship contents. try:
with tarfile.open(fileobj=self.wfile, mode="w|", dereference=True) as archive: # dereference: HF cache snapshots are symlinks into blobs/ — ship contents.
for rel in rel_files: with tarfile.open(fileobj=self.wfile, mode="w|", dereference=True) as archive:
archive.add(snapshot_dir / rel, arcname=rel) for rel in rel_files:
archive.add(snapshot_dir / rel, arcname=rel)
except (BrokenPipeError, ConnectionResetError):
print(
f"model-file download aborted by client "
f"({self.client_address[0]}, model={resolved_name})",
flush=True,
)
def _handle_network_assign(self, parsed: urllib.parse.ParseResult): def _handle_network_assign(self, parsed: urllib.parse.ParseResult):
"""Assign a new node to fill the biggest uncovered shard gap across HF-model nodes. """Assign a new node to fill the biggest uncovered shard gap across HF-model nodes.