The ETag shipped in fe9c4f49 is keyed on (source_hash, size, format),
which is one term short: a thumbnail is a function of those PLUS the
renderer. Change the encoder or a quality setting and identical inputs
produce different bytes under an unchanged ETag — the same staleness
class the commit fixed, one level down. It bites when an already-cached
thumbnail is re-rendered after a renderer change.
Keying on the derived blob's own hash removes the term entirely: the
ETag IS the hash of the bytes, so any output change invalidates by
construction. It is self-consistent for free, because store_derived_blob
is ON CONFLICT DO NOTHING — a re-render never displaces the stored row,
so the ETag always equals what the derived tier will serve. No renderer
version constant to remember to bump.
Records why it cannot land yet. The derived tier is read LAST by design,
so an ETag naming the derived hash would describe a tier the response
probably did not come from; sidecar and derived agree at creation but
diverge if a sidecar is re-rendered while the derived row stays pinned
by DO NOTHING. An ETag that lies about the body is worse than one that
is merely coarse. Also the tier is WebP-only (variant is the size, with
no format term) and empty for anything predating this work until
derived_import backfills.
So it lands at step 10 with the flip, keeping today's form as the
fallback for ungenerated variants and formats the tier does not hold.
The LEFT JOIN already planned for the read path returns the derived
hash in the same query, so it costs no extra round-trip.
Follows from the blob/chunk taxonomy already in this section: the job
iterates storage.blobs, which post-CDC holds chunks, so it inherits
whatever that table ends up called.
Two rules attached, because a job name is not an internal identifier —
it appears in POST /api/admin/jobs/<name>/trigger, in
background_runs.job_name, and in whatever dashboards operators built:
* Travel with the schema rename, never ahead of it. A job called
chunks_consistency iterating a table still called storage.blobs is
more confusing than today's mismatch.
* Never recycle `blobs_consistency`. Under the corrected taxonomy the
manifest job IS the blob-level job, so the freed name looks
available — and a name that survives a release while changing
meaning silently breaks admin URLs and orphans run history.
manifests_consistency is unambiguous either way, so exactly one job
gets renamed rather than two swapping.
Also records what is explicitly NOT renamed: the `.blob` on-disk suffix,
where correcting it to `.chunk` would mean renaming every file in every
deployment's blob store — a migration that can fail halfway, for
clarity no consumer benefits from since nothing parses the suffix. And
file.blob_hash, whose semantics are unchanged.
Docs only.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Enrich OxiCloud to maximise the use of `dedup` Engine
2 cases will be covered:
- blobs issues from other blobs (thumbnail automatic generation from blob)
- by filename (ex: thumbnail uploaded from users)
A local cache will be added when blobs are remote (S3 or similar)
Prevent services accessing directly to localstorage and prefer using an astraction layer
to expose full blob. The abstraction layer (dedup services) will cover backend storage
election (local, s3, ...), encryption, etc
This change permit audio_metadata_service, media_metadaa_service, face_indexing_service to handle
blobs without worring of the backend.
note: prefered way to handle blob is the streamed way. Some services may not have this possibility
Edouard Vanbelle