This is to ensure that Go contexts work properly, after some
interesting experiments I found that Go net/http doesn't
cancel the context when Body is non-zero and hasn't been
read till EOF.
The following gist explains this, this can lead to pile up
of go-routines on the server which will never be canceled
and will die at a really later point in time, which can
simply overwhelm the server.
https://gist.github.com/harshavardhana/c51dcfd055780eaeb71db54f9c589150
To avoid this refactor the locking such that we take locks after we
have started reading from the body and only take locks when needed.
Also, remove contextReader as it's not useful, doesn't work as expected
context is not canceled until the body reaches EOF so there is no point
in wrapping it with context and putting a `select {` on it which
can unnecessarily increase the CPU overhead.
We will still use the context to cancel the lockers etc.
Additional simplification in the locker code to avoid timers
as re-using them is a complicated ordeal avoid them in
the hot path, since locking is very common this may avoid
lots of allocations.
- Implement a new xl.json 2.0.0 format to support,
this moves the entire marshaling logic to POSIX
layer, top layer always consumes a common FileInfo
construct which simplifies the metadata reads.
- Implement list object versions
- Migrate to siphash from crchash for new deployments
for object placements.
Fixes#2111
This allows for canonicalization of the strings
throughout our code and provides a common space
for all these constants to reside.
This list is rather non-exhaustive but captures
all the headers used in AWS S3 API operations
Most hadoop distributions hortonworks, cloudera all
depend on aws-sdk-java 1.7.x to 1.10.x - the releases
which have bugs related case sensitive check for
ETag header. Go changes the case of the headers set
to be canonical but only preserves them when set
through a direct map.
This fixes most compatibility issues we have had
in the past supporting older hadoop distributions.
Copying an encrypted SSEC object when this latter is uploaded using
multipart mechanism was failing because ETag in case of encrypted
multipart upload is not encrypted.
This PR fixes the behavior.
CopyObject precondition checks into GetObjectReader
in order to perform SSE-C pre-condition checks using the
last 32 bytes of encrypted ETag rather than the decrypted
ETag
This also necessitates moving precondition checks for
gateways to gateway layer rather than object handler check
Different gateway implementations due to different backend
API errors, might return different unsupported errors at
our handler layer. Current code posed a problem for us because
this information was lost and we would convert it to InternalError
in this situation all S3 clients end up retrying the request.
To avoid this unexpected situation implement a way to support
this cleanly such that the underlying information is not lost
which is returned by gateway.
This PR adds disk based edge caching support for minio server.
Cache settings can be configured in config.json to take list of disk drives,
cache expiry in days and file patterns to exclude from cache or via environment
variables MINIO_CACHE_DRIVES, MINIO_CACHE_EXCLUDE and MINIO_CACHE_EXPIRY
Design assumes that Atime support is enabled and the list of cache drives is
fixed.
- Objects are cached on both GET and PUT/POST operations.
- Expiry is used as hint to evict older entries from cache, or if 80% of cache
capacity is filled.
- When object storage backend is down, GET, LIST and HEAD operations fetch
object seamlessly from cache.
Current Limitations
- Bucket policies are not cached, so anonymous operations are not supported in
offline mode.
- Objects are distributed using deterministic hashing among list of cache
drives specified.If one or more drives go offline, or cache drive
configuration is altered - performance could degrade to linear lookup.
Fixes#4026
This PR also does backend format change to 1.0.1
from 1.0.0. Backward compatible changes are still
kept to read the 'md5Sum' key. But all new objects
will be stored with the same details under 'etag'.
Fixes#4312
Golang HTTP client automatically detects content-type but
for S3 clients this content-type might be incorrect or
might misbehave.
For example:
```
Content-Type: text/xml; charset=utf-8
```
Should be
```
Content-Type: application/xml
```
Allow this to be set properly.
Harshavardhana