Disk level O_DIRECT support checking at xl storage initialization was
conditional on a config setting being enabled. (This never took effect
because config initialization happens after ObjectLayer is ready.) This
is not necessary as the config setting is dynamic - O_DIRECT should be
enabled via runtime config. So we need to do the disk level support
check regardless of the config setting.
not checking w.Close() can prematurely make us
think that the w.Write() actually succeeded, apparently
Write() may or may not return an error but sometimes
only during a Close() call to the fd we may see the
error from Write() propagate.
Fdatasync(w) on the FD would return an error requiring
Close() error handling is less of a concern, however it may
happen such that fdatasync() did not return an error, where
as Close() would.
Currently we have IOPs of these patterns
```
[OS] os.Mkdir play.min.io:9000 /disk1 2.718µs
[OS] os.Mkdir play.min.io:9000 /disk1/data 2.406µs
[OS] os.Mkdir play.min.io:9000 /disk1/data/.minio.sys 4.068µs
[OS] os.Mkdir play.min.io:9000 /disk1/data/.minio.sys/tmp 2.843µs
[OS] os.Mkdir play.min.io:9000 /disk1/data/.minio.sys/tmp/d89c8ceb-f8d1-4cc6-b483-280f87c4719f 20.152µs
```
It can be seen that we can save quite Nx levels such as
if your drive is mounted at `/disk1/minio` you can simply
skip sending an `Mkdir /disk1/` and `Mkdir /disk1/minio`.
Since they are expected to exist already, this PR adds a way
for us to ignore all paths upto the mount or a directory which
ever has been provided to MinIO setup.
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%
```
to track the replication transfer rate across different nodes,
number of active workers in use and in-queue stats to get
an idea of the current workload.
This PR also adds replication metrics to the site replication
status API. For site replication, prometheus metrics are
no longer at the bucket level - but at the cluster level.
Add prometheus metric to track credential errors since uptime
.metacache objects are transient in nature, and are better left to
use page-cache effectively to avoid using more IOPs on the disks.
this allows for incoming calls to be not taxed heavily due to
multiple large batch listings.
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
slower drives get knocked off because they are too slow via
active monitoring, we do not need to block calls arbitrarily.
Serializing adds latencies for already slow calls, remove
it for SSDs/NVMEs
Also, add a selection with context when writing to `out <-`
channel, to avoid any potential blocks.
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.
