Keep the EC in header, so it can be retrieved easily for dynamic quorum calculations.
To not force a full metadata decode on every read the value will be 0/0 for data written in previous versions.
Size is expected to increase by 2 bytes per version, since all valid values can be represented with 1 byte each.
Example:
```
λ xl-meta xl.meta
{
"Versions": [
{
"Header": {
"EcM": 4,
"EcN": 8,
"Flags": 6,
"ModTime": "2024-04-17T11:46:25.325613+02:00",
"Signature": "0a409875",
"Type": 1,
"VersionID": "8e03504e11234957b2727bc53eda0d55"
},
...
```
Not used for operations yet.
Create new code paths for multiple subsystems in the code. This will
make maintaing this easier later.
Also introduce bugLogIf() for errors that should not happen in the first
place.
Merging same-object - multiple versions from different pools would not always result in correct ordering.
When merging keep inputs separate.
```
λ mc ls --versions local/testbucket
------ before ------
[2024-03-05 20:17:19 CET] 228B STANDARD 1f163718-9bc5-4b01-bff7-5d8cf09caf10 v3 PUT hosts
[2024-03-05 20:19:56 CET] 19KiB STANDARD null v2 PUT hosts
[2024-03-05 20:17:15 CET] 228B STANDARD 73c9f651-f023-4566-b012-cc537fdb7ce2 v1 PUT hosts
------ after ------
λ mc ls --versions local/testbucket
[2024-03-05 20:19:56 CET] 19KiB STANDARD null v3 PUT hosts
[2024-03-05 20:17:19 CET] 228B STANDARD 1f163718-9bc5-4b01-bff7-5d8cf09caf10 v2 PUT hosts
[2024-03-05 20:17:15 CET] 228B STANDARD 73c9f651-f023-4566-b012-cc537fdb7ce2 v1 PUT hosts
```
fixes#18724
A regression was introduced in #18547, that attempted
to file adding a missing `null` marker however we
should not skip returning based on versionID instead
it must be based on if we are being asked to create
a DEL marker or not.
The PR also has a side-affect for replicating `null`
marker permanent delete, as it may end up adding a
`null` marker while removing one.
This PR should address both scenarios.
Bonus: allow replication to attempt Deletes/Puts when
the remote returns quorum errors of some kind, this is
to ensure that MinIO can rewrite the namespace with the
latest version that exists on the source.
objects with 10,000 parts and many of them can
cause a large memory spike which can potentially
lead to OOM due to lack of GC.
with previous PR reducing the memory usage significantly
in #17963, this PR reduces this further by 80% under
repeated calls.
Scanner sub-system has no use for the slice of Parts(),
it is better left empty.
```
benchmark old ns/op new ns/op delta
BenchmarkToFileInfo/ToFileInfo-8 295658 188143 -36.36%
benchmark old allocs new allocs delta
BenchmarkToFileInfo/ToFileInfo-8 61 60 -1.64%
benchmark old bytes new bytes delta
BenchmarkToFileInfo/ToFileInfo-8 1097210 227255 -79.29%
```
- this PR avoids sending a large ChecksumInfo slice
when its not needed
- also for a file with XLV2 format there is no reason
to allocate Checksum slice while reading
Indexed streams would be decoded by the legacy loader if there
was an error loading it. Return an error when the stream is indexed
and it cannot be loaded.
Fixes "unknown minor metadata version" on corrupted xl.meta files and
returns an actual error.
ListObjects, ListObjectsV2 calls are being heavily taxed when
there are many versions on objects left over from a previous
release or ILM was never setup to clean them up. Instead
of being absolutely correct at resolving the exact latest
version of an object, we simply rely on the top most 1
version and resolve the rest.
Once we have obtained the top most "1" version for
ListObject, ListObjectsV2 call we break out.
- GetObject() with vid should return 405
- GetObject() without vid should return 404
- ListObjects() should ignore this object if this is the "latest" version of the object
- ListObjectVersions() should list this object as "DELETE marker"
- Remove data parts before sync'ing the version pending purge
```
tmp = buf[want:]
```
Would potentially crash when `buf` is truncated for some reason
and does not have the expected bytes, this is of course considered
not normal and is an odd situation. But we do not need to crash
here instead allow for errors to be returned and let callers handle
the errors.
This is a side-affect of the optimization done in PR #13544 which
causes a certain type of delete operations on given object versions
can cause lastVersion indication to be skipped, which leads to
an `xl.meta` where Versions[] slice is empty while the entire
file is intact by itself.
This PR tries to ensure that such files are visible and deletable
by regular means of listing as null 'delete-marker' and also
avoid the situation where this potential issue might arise.
When calculating signatures empty part ETags were not discarded, leading
to a different signature compared to freshly created ones.
This would mean that after a heal signature of the healed metadata would be
different. Fixing the calculation of signature will make these consistent.
Furthermore when inconsistent entries, with zero version ID, with the same
mod times but different signatures, the one with the lowest signature would
be picked for quorum check. Since this is 50/50, we fall back to a simple
quorum count on all signatures.
Each of these fixes by themselves will lead to quorum. Tests were added
for regressions and expected outcomes.
In a multi-pool setup when disks are coming up, or in a single pool
setup let's say with 100's of erasure sets with a slow network.
It's possible when healing is attempted on `.minio.sys/config`
folder, it can lead to healing unexpectedly deleting some policy
files as dangling due to a mistake in understanding when `isObjectDangling`
is considered to be 'true'.
This issue happened in commit 30135eed86
when we assumed the validMeta with empty ErasureInfo is considered
to be fully dangling. This implementation issue gets exposed when
the server is starting up.
This is most easily seen with multiple-pool setups because of the
disconnected fashion pools that come up. The decision to purge the
object as dangling is taken incorrectly prior to the correct state
being achieved on each pool, when the corresponding drive let's say
returns 'errDiskNotFound', a 'delete' is triggered. At this point,
the 'drive' comes online because this is part of the startup sequence
as drives can come online lazily.
This kind of situation exists because we allow (totalDisks/2) number
of drives to be online when the server is being restarted.
Implementation made an incorrect assumption here leading to policies
getting deleted.
Added tests to capture the implementation requirements.
single object delete was not working properly
on a bucket when versioning was suspended,
current version 'null' object was never removed.
added unit tests to cover the behavior
fixes#13783
Existing:
```go
type xlMetaV2 struct {
Versions []xlMetaV2Version `json:"Versions" msg:"Versions"`
}
```
Serialized as regular MessagePack.
```go
//msgp:tuple xlMetaV2VersionHeader
type xlMetaV2VersionHeader struct {
VersionID [16]byte
ModTime int64
Type VersionType
Flags xlFlags
}
```
Serialize as streaming MessagePack, format:
```
int(headerVersion)
int(xlmetaVersion)
int(nVersions)
for each version {
binary blob, xlMetaV2VersionHeader, serialized
binary blob, xlMetaV2Version, serialized.
}
```
xlMetaV2VersionHeader is <= 30 bytes serialized. Deserialized struct
can easily be reused and does not contain pointers, so efficient as a
slice (single allocation)
This allows quickly parsing everything as slices of bytes (no copy).
Versions are always *saved* sorted by modTime, newest *first*.
No more need to sort on load.
* Allows checking if a version exists.
* Allows reading single version without unmarshal all.
* Allows reading latest version of type without unmarshal all.
* Allows reading latest version without unmarshal of all.
* Allows checking if the latest is deleteMarker by reading first entry.
* Allows adding/updating/deleting a version with only header deserialization.
* Reduces allocations on conversion to FileInfo(s).
Klaus Post
Anis Eleuch
Harshavardhana
jiuker
Krishnan Parthasarathi
Aditya Manthramurthy
ferhat elmas
Poorna