sendfile implementation to perform DMA on all platforms
Go stdlib already supports sendfile/splice implementations
for
- Linux
- Windows
- *BSD
- Solaris
Along with this change however O_DIRECT for reads() must be
removed as well since we need to use sendfile() implementation
The main reason to add O_DIRECT for reads was to reduce the
chances of page-cache causing OOMs for MinIO, however it would
seem that avoiding buffer copies from user-space to kernel space
this issue is not a problem anymore.
There is no Go based memory allocation required, and neither
the page-cache is referenced back to MinIO. This page-
cache reference is fully owned by kernel at this point, this
essentially should solve the problem of page-cache build up.
With this now we also support SG - when NIC supports Scatter/Gather
https://en.wikipedia.org/wiki/Gather/scatter_(vector_addressing)
With the current asynchronous behaviour in sending notification events
to the targets, we can't provide guaranteed delivery as the systems
might go for restarts.
For such event-driven use-cases, we can provide an option to enable
synchronous events where the APIs wait until the event is successfully
sent or persisted.
This commit adds 'MINIO_API_SYNC_EVENTS' env which when set to 'on'
will enable sending/persisting events to targets synchronously.
The `LookupConfig` code was not using `GetWithDefault`, because of which
some of the config values were being returned as empty string, and calls
like `strconv.Atoi` and `time.ParseDuration` on these were failing.
Enabled with `mc admin config set alias/ api gzip_objects=on`
Standard filtering applies (1K response minimum, not compressed content
type, not range request, gzip accepted by client).
repeated reads on single large objects in HPC like
workloads, need the following option to disable
O_DIRECT for a more effective usage of the kernel
page-cache.
However this optional should be used in very specific
situations only, and shouldn't be enabled on all
servers.
NVMe servers benefit always from keeping O_DIRECT on.
with some broken clients allow non-strict validation
of sha256 when ContentLength > 0, it has been found in
the wild some applications that need this behavior. This
shall be only allowed if `--no-compat` is used.
This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`
