if erasure upgrade is needed rely on the in-memory
values, instead of performing a "DiskInfo()" call.
https://brendangregg.com/blog/2016-09-03/sudden-disk-busy.html
for HDDs these are problematic, lets avoid this because
there is no value in "being" absolutely strict here
in terms of parity. We are okay to increase parity
as we see based on the in-memory online/offline ratio.
Bonus fixes include
- do not have to write final xl.meta (renameData) does this
already, saves some IOPs.
- make sure to purge the multipart directory properly using
a recursive delete, otherwise this can easily pile up and
rely on the stale uploads cleanup.
fixes#17863
there is a possibility that slow drives can actually add latency
to the overall call, leading to a large spike in latency.
this can happen if there are other parallel listObjects()
calls to the same drive, in-turn causing each other to sort
of serialize.
this potentially improves performance and makes PutObject()
also non-blocking.
on "unversioned" buckets there are situations
when successive concurrent I/O can lead to
an inconsistent state() with mtime while the
etag might be the same for the object on disk.
in such a scenario it is possible for us to
allow reading of the object since etag matches
and if etag matches we are guaranteed that we
have enough copies the object will be readable
and same.
This PR allows fallback in such scenarios.
Removes the bloom filter since it has so limited usability, often gets saturated anyway and adds a bunch of complexity to the scanner.
Also removes a tiny bit of CPU by each write operation.
Move to using `xl.meta` data structure to keep temporary partInfo,
this allows for a future change where we move to different parts to
different drives.
PUT shall only proceed if pre-conditions are met, the new
code uses
- x-minio-source-mtime
- x-minio-source-etag
to verify if the object indeed needs to be replicated
or not, allowing us to avoid StatObject() call.
The path is marked dirty automatically when healObject() is called, which is
wrong. HealObject() is called during self-healing and this will lead to
an increase in the false positive result of the bloom filter.
Also move NSUpdated() from renameData() and call it directly in
CompleteMultipart and PutObject, this is not a functional change but
it will make it less prone to errors in the future.
Do completely independent multipart uploads.
In distributed mode, a lock was held to merge each multipart
upload as it was added. This lock was highly contested and
retries are expensive (timewise) in distributed mode.
Instead, each part adds its metadata information uniquely.
This eliminates the per object lock required for each to merge.
The metadata is read back and merged by "CompleteMultipartUpload"
without locks when constructing final object.
Co-authored-by: Harshavardhana <harsha@minio.io>
Uploading a part object can leave an inconsistent state inside
.minio.sys/multipart where data are uploaded but xl.meta is not
committed yet.
Do not list upload-ids that have this state in the multipart listing.
