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HDDS-16082. [Ozone versioning] [T5] SUSPENDED semantics - #10955

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HDDS-16082. [Ozone versioning] [T5] SUSPENDED semantics#10955
symious wants to merge 22 commits into
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symious:HDDS-16082

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@symious symious commented Aug 5, 2026

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What changes were proposed in this pull request?

Please only review commits starts with "T5".

Sub-task Scope Acceptance
T5.1 PUT null-slot overwrite SUSPENDED PUT locates and replaces the null slot no version accumulation; old null-version data reclaimed; Enabled-era versions unaffected.the new record becomes the current version even when the null slot was noncurrent
T5.2 DELETE null marker SUSPENDED DELETE writes an isNullVersion=true marker overwrites the existing null slot; historical versions stay readable/deletable by versionId
T5.3 pre-versioning keys, zero migration keys written before enabling versioning interpreted as null versions no data rewrite of any kind; versionId=null addressing hits the legacy record
T5.4 MPU version retention multipart upload completion follows the same version-retention path as PUT the superseded version is demoted to the versionedKeyTable instead of being dropped — it stays readable by versionId and its blocks are neither leaked nor reclaimed; the completed key carries a generated versionId; a SUSPENDED completion takes the null slot with the same semantics as T5.1

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-16082

How was this patch tested?

unit test

symious and others added 8 commits August 18, 2026 10:28
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
…equest

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Key names in OBJECT_STORE buckets contain '/' verbatim, so a '/' separator
interleaves a key's versions with those of keys nested under it, breaking
the single-seek promotion and the merged ListObjectVersions order.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
symious and others added 6 commits August 20, 2026 09:59
Adds VersionIdGenerator, the pluggable source of the id an object version
is numbered with, and UniqueIdVersionIdGenerator as the cluster default.

The id is proposed on the OM that received the request, in preExecute, so
it travels in the replicated request and every OM applies a version that
is already numbered. Nothing about it depends on the transaction carrying
the write, or on OM being replicated by Ratis.

The default numbers a version with the time it was written, through the
scheme Ozone already uses for block local IDs: currentTimeMillis << 16
with a 16-bit counter separating ids proposed inside one millisecond. It
needs no allocator state and no coordination, which is what makes it safe
to read on any OM.

The interface has one abstract method, generateVersionId(), plus a default
versionIdFor(proposed, hasCurrentVersion) that lets a generator number
some versions specially at apply time. The implementation is selected
cluster-wide by ozone.om.versioning.version-id-generator.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Adds VersionIdAllocator, which turns the id proposed for a version into
the id it is applied with.

versionedKeyTable orders a key's versions by Long.MAX_VALUE - versionId,
so the ids of one key have to increase in the order the versions were
written. A proposal is a clock reading and cannot promise that: ids
proposed inside one millisecond can exhaust the counter separating them,
and a leader change onto a lagging clock proposes a lower value.

So a proposal is a floor. The applied id is the later of it and the id
after the key's current version, which the write path already holds - no
read of its own, no global state, and identical on every OM. Under a clock
regression an affected key's ids climb by one until proposals overtake
them again: the versions stay ordered and only the id's reading as a time
degrades.

propose() runs in preExecute on the OM that received the request;
allocate() runs under the write's lock on every OM.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Adds PinnedFirstVersionIdGenerator, which numbers versions like the
default except that a key's first version takes FIRST_VERSION_ID, so it
can be referenced without listing the key's versions first.

Whether the key already has a version is not known when the id is
proposed, so the generator decides it in versionIdFor, under the write's
lock, from the current version the allocator was handed.

The sentinel is 1: below every proposed id, so a pinned version sorts at
the old end of the key in versionedKeyTable, and above the unset value a
pre-versioning record carries. It says nothing about the null version,
which carries a proposed id like any other and is marked by isNullVersion.

Known trade-off: once every version of a key has been permanently deleted,
a recreated key takes the sentinel again, so an external reference to the
first version resolves to the new content. The generator is off by default
and selected by ozone.om.versioning.version-id-generator.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
On a versioning-enabled bucket a commit no longer reclaims the version it
overwrites: the previous current version moves to the versionedKeyTable
and the new record becomes current, in one WriteBatch. A record written
before versioning was enabled carries no versionId and becomes the key's
null version.

The new version is numbered from KeyArgs.proposedVersionId, which
preExecute stamps into the request on the OM that received it, so every
OM applies the same id and nothing is generated during apply. The
allocator raises the proposal to come after the key's current version
when it does not already. An hsync re-commit keeps updating the version
it opened, so it keeps its versionId and moves nothing.

Both reclaim branches now depend on the versioning status rather than on
the legacy isVersionEnabled flag being kept in sync with it, so dropping
that sync cannot strand a version record by reclaiming the blocks it
still refers to. S3MultipartUploadCompleteRequest is guarded the same way;
it does not yet record a version for the key it supersedes, so an MPU
overwrite on a versioned bucket leaks those blocks until T5 lands.
OMKeyCommitRequestWithFSO is left alone: isS3VersioningEnabled() requires
the OBJECT_STORE layout, so the check is structurally false there.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A delete without a versionId on a versioning-enabled bucket removes no
data: a delete marker becomes the key's current version and the version
it supersedes moves to the versionedKeyTable. As in S3, the marker is
inserted even when the key does not exist.

The marker is a version, so its id comes from KeyArgs.proposedVersionId
the same way a commit's does, proposed in preExecute and raised to come
after the key's current version at apply time.

The failure response declares the same tables as the successful one: the
double buffer cleans the table cache from the response's CleanupTableInfo,
so a marker request that failed after touching the versionedKeyTable cache
would otherwise leave an entry behind that is in no DB and never cleaned.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
symious and others added 5 commits August 20, 2026 17:55
A batch delete is the same operation over more keys, but it goes through
a request of its own and that one still hard-deleted on a versioned
bucket: the current version's blocks were reclaimed and the versions
underneath were left in the versionedKeyTable with nothing in the keyTable
above them. Those versions then read as absent, hold quota, and cannot be
promoted, because promotion only runs when a version is deleted by id.

The gap opens with T3.1, where the two tables first diverge, so it is
closed here rather than later. It is reachable today: the S3 gateway wires
DeleteObjects straight to this request, and so does the client's
deleteKeys API.

Rather than write a second marker implementation, the one T3.2 added moves
to OMKeyRequest and returns what it changed, so the single-key and batch
requests build their own responses from the same insertion. One proposed
versionId covers a batch: an id only has to increase within one key, and
the applying OM raises it per key against that key's own current version.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
GET/HEAD/lookup can address one version of a key instead of its current
one: KeyArgs carries either a versionId or nullVersion, at most one. A
versionId naming the current version is answered from the keyTable with
no versionedKeyTable read; anything else is a point lookup there. The null
version is found by its isNullVersion attribute rather than by id, because
it carries a normally proposed id like any other version.

A read that lands on a current delete marker is a plain not-found, while
one that names a marker by id - current or not - is KEY_IS_DELETE_MARKER,
which the gateway turns into S3's 405. The marker is addressable wherever
it sits, so the two conditions stay distinct.

Only OBJECT_STORE buckets can hold versions, so addressing a version on
any other layout is NOT_SUPPORTED_OPERATION. The check is on the layout
rather than on isFileSystemOptimized(), because LEGACY reaches the same
lookup path as OBJECT_STORE and would otherwise scan the versionedKeyTable
and report the key not found.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
DELETE ?versionId= is the only delete that destroys data on a versioned bucket:
the version leaves the versionedKeyTable and its blocks go to the deletedTable,
which stays the single path through which version blocks are reclaimed. The null
slot is addressed by attribute, so it is found by the same bounded prefix scan
the read path uses.

Addressing the current version is rejected for now: removing it has to promote
the next-newest version to keep the keyTable authoritative, which T4.3 adds.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
keyTable holds the current version of every key that still has one, so removing
the current version has to hand the place over: one seek on the key's version
prefix yields the newest remaining version, which moves back into the keyTable
in the same WriteBatch as the delete. The record travels unchanged - promotion
is positional, and a version keeps the identity it was created with. When no
version survives, the key disappears entirely.

Deleting a current delete marker this way is exactly S3's restore-an-object
flow: the version the marker superseded becomes current again.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
…nded

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
symious and others added 3 commits August 21, 2026 11:19
Suspending versioning stops new versions from being created; it does not
stop the ones already there from being protected. So a delete still writes
a marker, but the marker is the key's null version: it replaces whatever
held that slot rather than superseding it, and only that record is
destroyed. Versions written while versioning was enabled stay readable and
deletable by versionId.

Both delete paths take this route. The batch request branched on ENABLED
alone, which would have hard-deleted on a suspended bucket and stranded the
versions underneath - the same data loss the single-key path was changed to
avoid, just in a different bucket state. Its response now also writes out
the null slot the marker replaced: dropping the versionedKeyTable record
and queueing its blocks, which the quota accounting has already been
charged for.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Completing a multipart upload creates a version like any other write: the
version it supersedes is kept in the versionedKeyTable instead of being
reclaimed, except for the null version, which a suspended write replaces
outright. This closes the block leak an MPU overwrite left on a versioned
bucket, where the previous version's blocks were neither reclaimed nor
recorded.

The new version is numbered from KeyArgs.proposedVersionId, stamped in
preExecute like a commit's, and is marked as the null version while
versioning is suspended.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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