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

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HDDS-16082. [Ozone versioning] [T5] SUSPENDED semantics#10955
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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T5.4 MPU version retention multipart upload completion follows the same version-retention path as PUT the superseded version is demoted to the versionedKeyTable instead of being dropped — it stays readable by versionId and its blocks are neither leaked nor reclaimed; the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
symious force-pushed the HDDS-16082 branch 7 times, most recently from a6437d8 to 742c750 Compare August 24, 2026 07:51
symious and others added 22 commits August 28, 2026 11:07
S3 gives a bucket three versioning states, while Ozone has a single
isVersionEnabled boolean. This adds the three-state status alongside the
flag rather than in place of it, so existing buckets and older clients go
on working unchanged.

BucketVersioningStatus holds the three states and the state machine that
governs them: UNVERSIONED may move anywhere, but once versioning has been
enabled or suspended a bucket can never return to UNVERSIONED. The proto
gains a matching enum and an optional versioningStatus on both BucketInfo
and BucketArgs.

OmBucketInfo keeps the two representations in sync in both directions: a
status derives the flag (ENABLED -> true), and a record carrying only the
flag derives a status, so a bucket written before this change still
answers getVersioningStatus(). Disabling the flag is the asymmetric case -
it leaves an explicitly SUSPENDED status alone, since the state machine
has no way back to UNVERSIONED.

Nothing enforces the state machine yet; this commit only defines it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
A bucket's versioning status may only change along the state machine the
previous commit defined. OMBucketSetPropertyRequest now checks the
requested status against the one the bucket already holds and rejects
with INVALID_REQUEST what the state machine forbids - the return to
UNVERSIONED once versioning has been enabled or suspended.

A request carrying only the legacy flag is mapped onto the same machine
before that check: enabling always means ENABLED, while disabling means
SUSPENDED, except on a bucket that is still UNVERSIONED, where it stays
UNVERSIONED.

The status is refused outright at bucket creation. S3 has no way to create
a bucket already in a versioning state: CreateBucket carries no such
parameter, and the state is set afterwards through PutBucketVersioning.
versioningStatus sits on BucketInfo because that message is the bucket's
on-disk record and the shape InfoBucket and ListBuckets return, not
because CreateBucket needs it; honouring it there would let a caller land
on any status in one step, with none of the above applied. Nothing
populates the field on a create today, so the request is rejected rather
than quietly ignored - ignoring it would leave a future caller believing
it had created a versioned bucket.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 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>
Each section below was a separate commit; they are folded
here so the task's review fixes land as one change.

* Address comments

* Use a 0x00 separator in versionedKeyTable dbKeys

  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.

* Do not derive a versioning status from the legacy flag

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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>
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, so
no dbKey addresses it. That search reads the table cache as well as the
DB: Table.iterator() goes straight to RocksDB, and a version demoted by a
transaction the double buffer has not flushed yet lives only in the
cache, so an iterator-only scan would report a version that exists as
missing while the point lookups beside it, which do consult the cache,
resolve it.

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.
S3 answers such a read with 405 rather than 404, which is why the two
conditions stay distinct; the gateway mapping arrives with the endpoints.

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>
Each section below was a separate commit; they are folded
here so the task's review fixes land as one change.

* Send the addressed version with the request

  OmKeyArgs.toProtobuf() left versionId and nullVersion out, so a client
  that addressed a specific version had the request silently downgraded to
  a read of the current one. The OM already reads both fields off KeyArgs
  in the lookupKey and getKeyInfo handlers, and toBuilder() already carries
  them, so only the proto conversion was missing.

  Nothing hits this yet because the client and S3 gateway do not address
  versions themselves, but it would be an awkward bug to find once they do.

* Refuse a request that names a version twice

  S3 names the null version with the literal versionId "null", so exactly
  one of versionId and nullVersion is set on a well-formed request. Both
  being set was not refused: the OmKeyArgs builder keeps the two mutually
  exclusive by dropping one when the other is set, so a read silently
  resolved to the null version, and the delete path picked whichever field
  it looked at first.

  The check now runs where the proto arrives - the lookupKey and getKeyInfo
  handlers, and the delete request's preExecute - and returns
  INVALID_REQUEST rather than answering an ambiguous request.

* Name the version delete by the key it deletes

  The dbKey the version is removed from was called versionedKey and left
  null when the current version was the one addressed, so the response was
  handed deletingCurrent ? objectKey : versionedKey - the request working
  out which table the key belongs to, which the response already decides
  from deletedCurrent when it picks the table to delete from.

  The variable now holds the key in both cases and is named for what it is.
  No behaviour change.

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

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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>
Enabling versioning does not rewrite the objects a bucket already holds, and
S3 reports the version of such an object as "null". A record written before
versioning carries no versionId at all, while one written while versioning
was suspended carries the isNullVersion flag; a request naming version "null"
addresses either, so the sites that resolve it match on isNullVersionRecord()
rather than on the flag alone - the read path, the search of a key's
noncurrent versions, and deleteVersion's check for whether the addressed
version is the current one.

A key still has at most one null version either way, since a suspended write
replaces whichever one the key already has.

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>
Each section below was a separate commit; they are folded
here so the task's review fixes land as one change.

* Check the quota against what a suspended write nets

  A suspended write that replaces the key's null version removes a record
  as it adds one, but the quota was checked before the removal was
  accounted for: the namespace check asked for one record and the byte
  check for the new record's full size, and only afterwards were the
  replaced version's usage and slot given back. A bucket sitting exactly at
  its namespace quota therefore rejected a write that leaves its record
  count unchanged, and one near its space quota rejected a write that
  leaves it smaller.

  The replaced version is now resolved before the checks and folded into
  both deltas, so what is checked is what the transaction nets. The lookup
  moving ahead of the retention below is safe: a null version record is
  never retained, so the record retained there always carries a real
  versionId and cannot be what the lookup finds.

* Delete the null version of a never-versioned bucket

  S3 calls the object itself the null version wherever a bucket has no
  version history, so DELETE ?versionId=null works on a bucket that was
  never versioned and removes the object. The read path already answers it
  that way - it gates on the bucket layout, not on the versioning status -
  while the delete refused it as unsupported, so the same request could be
  read but not deleted.

  It now falls through to the plain delete. An id still names nothing on
  such a bucket and stays unsupported, and the layout gate the read path
  applies is now explicit here rather than implied by the versioning status
  never being set outside OBJECT_STORE.

* Check the marker's quota against what it nets

  A delete marker that takes the key's null version slot replaces a record
  rather than adding one, but the namespace check asked for a record before
  the replaced version's slot was given back, so a bucket sitting exactly
  at its namespace quota rejected a delete that leaves its record count
  unchanged. This is the same ordering as on the commit path, in the delete
  marker path that OMKeyDeleteRequest and OMKeysDeleteRequest share.

  It covers the marker replacing a noncurrent null version too, not only
  the current one: the current version is demoted in that case, so the
  marker still nets no record.

* Build the delete marker from a stated set of fields

  The marker was a copy of the version it supersedes with the content
  cleared out afterwards, so it inherited everything OmKeyInfo happens to
  carry - encryption info, storage policy, parent and file name - and a
  field added later would land on markers by default.

  It is now built once from the fields a marker is meant to have: the key's
  identity - objectID, owner, replication and ACLs - and nothing describing
  content it does not hold.

* Note why a marker can have no version to inherit from

* Take the replaced null version in the constructor

  The delete marker response was completed by a call after construction, so
  a caller that forgot it got a response that silently skipped removing the
  replaced null version and queueing its blocks. There is one call site and
  no subclass, so the two fields are constructor arguments now.

  OMKeyCommitResponse keeps its setter: OMKeyCommitResponseWithFSO passes
  the constructor through, and an FSO bucket can never be versioned, so the
  field would only ever be null there.

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