Guarantee 1 is "durably stored in the configured bucket before the
response completes". The tee sent every chunk straight through, so the
client saw the last byte before the multipart upload was completed and
well before the manifest referenced it. A client that read a file and
immediately failed over to a sealed instance could be told the file had
never been seen -- and if either storage phase failed, it had already
received a clean 200 over bytes nothing recorded.
The tee now runs one chunk behind and releases the final chunk only
after the upload completes and the manifest write lands. Content-Length
is already on the wire, so a client cannot treat the transfer as
complete without those bytes; a storage or manifest failure now ends the
body short instead, which is what the client detects and retries on.
Costs one chunk of extra latency at the end of a transfer and nothing
else: the withheld chunk is bounded by the upstream chunk size, and a
disconnected client still has its transfer finished without it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XZG2i4AmfSqE97EJGBVb64
A snapshot_download fans out across a repo's files, so several transfers
finish at once and each rewrites the same manifest document. The
read-merge-write had no conditional put behind it: two writers that read
the same document both wrote their own version, and the second silently
dropped the first's entry. The verify-after-write retry caught most of
that, but the write happens in the detached transfer task -- after the
client already has its bytes -- so a lost entry surfaced only later, as a
sealed instance claiming never to have seen a file it had served. That
breaks the fetch-once retention guarantee.
Adds a compare-and-set pair to the Store port (get_versioned /
put_if_version, conditional on the etag last read) and uses it for
manifest updates, so a racing write is refused and retried rather than
merged away. The local filesystem store cannot do conditional updates,
so it reports supports_compare_and_set() = false and the caller keeps
the verify-after-write path for it.
Also serialises manifest writes per key within the process. CAS alone is
correct but turns eight parallel workers into eight writers contending
for one document, burning the retry budget on self-inflicted collisions;
the lock makes the common case uncontended and leaves the retry loop for
genuinely concurrent writers -- another instance, or the CLI against the
same bucket.
Regression test fetches twelve files of one repo concurrently and
asserts every one survives into the manifest and replays when sealed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XZG2i4AmfSqE97EJGBVb64
Scaffolds the workspace per architecture/generic.md §1 and implements
phases 0-3 of doc/spec.md §12.
Crates:
entities manifest/ref/repo schemas, bucket key layout, config, the
X-Error-Code taxonomy. No I/O.
core resolver, freeze pinning, single-flight, the streaming tee,
policy, gc/verify/refresh. Defines the Store and Upstream
ports.
data object_store (S3 + local) and reqwest Hub adapters.
api the axum surface: resolve, model/dataset info, tree, refs,
whoami, metrics, bearer auth, range handling.
bin one binary: serve plus fetch/pin/refresh/list/show/rm/gc/
verify/doctor.
Deployment targets bob.hanzalova.internal:20482 (port derived per
architecture/port-allocations.md §3), storing to the MinIO on
caveman.kosherinata.internal, fronted by hanzalova at rf.internal.
Ships the sysusers drop-in, hardened unit, firewalld service, nginx
vhost, config template, infra-setup.sh and the Gitea Actions
ci/deploy/conformance workflows.
Testing: 112 unit and integration tests, including the sovereignty
suite (cold fetch, sealed replay, single-flight, client disconnect,
range resume, freeze stability, gc-after-rm, digest mismatch), plus a
conformance suite driving a pinned huggingface_hub against a real Hub.
Deviations from the spec, all deliberate:
- one binary with subcommands (spec §9) rather than generic.md's
separate -api and -cli binaries; the library split is unchanged.
- a dedicated sysusers account and hardened unit (generic.md §8)
rather than the spec's illustrative DynamicUser unit.
- manifests carry an optional repo_tree recorded verbatim, resolving
spec §13's "record whole, filter on read" question for the tree
endpoint as well as model-info.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XZG2i4AmfSqE97EJGBVb64
grenadeandClaude Opus 5