This PR adds a WebSocket grid feature that allows servers to communicate via
a single two-way connection.
There are two request types:
* Single requests, which are `[]byte => ([]byte, error)`. This is for efficient small
roundtrips with small payloads.
* Streaming requests which are `[]byte, chan []byte => chan []byte (and error)`,
which allows for different combinations of full two-way streams with an initial payload.
Only a single stream is created between two machines - and there is, as such, no
server/client relation since both sides can initiate and handle requests. Which server
initiates the request is decided deterministically on the server names.
Requests are made through a mux client and server, which handles message
passing, congestion, cancelation, timeouts, etc.
If a connection is lost, all requests are canceled, and the calling server will try
to reconnect. Registered handlers can operate directly on byte
slices or use a higher-level generics abstraction.
There is no versioning of handlers/clients, and incompatible changes should
be handled by adding new handlers.
The request path can be changed to a new one for any protocol changes.
First, all servers create a "Manager." The manager must know its address
as well as all remote addresses. This will manage all connections.
To get a connection to any remote, ask the manager to provide it given
the remote address using.
```
func (m *Manager) Connection(host string) *Connection
```
All serverside handlers must also be registered on the manager. This will
make sure that all incoming requests are served. The number of in-flight
requests and responses must also be given for streaming requests.
The "Connection" returned manages the mux-clients. Requests issued
to the connection will be sent to the remote.
* `func (c *Connection) Request(ctx context.Context, h HandlerID, req []byte) ([]byte, error)`
performs a single request and returns the result. Any deadline provided on the request is
forwarded to the server, and canceling the context will make the function return at once.
* `func (c *Connection) NewStream(ctx context.Context, h HandlerID, payload []byte) (st *Stream, err error)`
will initiate a remote call and send the initial payload.
```Go
// A Stream is a two-way stream.
// All responses *must* be read by the caller.
// If the call is canceled through the context,
//The appropriate error will be returned.
type Stream struct {
// Responses from the remote server.
// Channel will be closed after an error or when the remote closes.
// All responses *must* be read by the caller until either an error is returned or the channel is closed.
// Canceling the context will cause the context cancellation error to be returned.
Responses <-chan Response
// Requests sent to the server.
// If the handler is defined with 0 incoming capacity this will be nil.
// Channel *must* be closed to signal the end of the stream.
// If the request context is canceled, the stream will no longer process requests.
Requests chan<- []byte
}
type Response struct {
Msg []byte
Err error
}
```
There are generic versions of the server/client handlers that allow the use of type
safe implementations for data types that support msgpack marshal/unmarshal.
competing calls on the same object on versioned bucket
mutating calls on the same object may unexpected have
higher delays.
This can be reproduced with a replicated bucket
overwriting the same object writes, deletes repeatedly.
For longer locks like scanner keep the 1sec interval
.Reset() documentation states:
For a Timer created with NewTimer, Reset should be invoked only on stopped
or expired timers with drained channels.
This change is just to comply with this requirement as there might be some
runtime dependent situation that might lead to unexpected behavior.
it seems in some places we have been wrongly using the
timer.Reset() function, nicely exposed by an example
shared by @donatello https://go.dev/play/p/qoF71_D1oXD
this PR fixes all the usage comprehensively
The code was not properly deciding if a lock needs to be removed
when it doesn't have quorum anymore. After this commit, a lock will be
forcefully unlocked if nodes reporting they are not able to find a lock
internally breaks the quorum.
Simplify the code as well.
- remove some duplicated code
- reported a bug, separately fixed in #13664
- using strings.ReplaceAll() when needed
- using filepath.ToSlash() use when needed
- remove all non-Go style comments from the codebase
Co-authored-by: Aditya Manthramurthy <donatello@users.noreply.github.com>
also simplify readerLocks to be just like
writeLocks, DRWMutex() is never shared
and there are order guarantees that need
for such a thing to work for RLock's
it would seem like using `bufio.Scan()` is very
slow for heavy concurrent I/O, ie. when r.Body
is slow , instead use a proper
binary exchange format, to marshal and unmarshal
the LockArgs datastructure in a cleaner way.
this PR increases performance of the locking
sub-system for tiny repeated read lock requests
on same object.
```
BenchmarkLockArgs
BenchmarkLockArgs-4 6417609 185.7 ns/op 56 B/op 2 allocs/op
BenchmarkLockArgsOld
BenchmarkLockArgsOld-4 1187368 1015 ns/op 4096 B/op 1 allocs/op
```
This was a regression introduced in '14bb969782'
this has the potential to cause corruption when
there are concurrent overwrites attempting to update
the content on the namespace.
This PR adds a situation where PutObject(), CopyObject()
compete properly for the same locks with NewMultipartUpload()
however it ends up turning off competing locks for the actual
object with GetObject() and DeleteObject() - since they do not
compete due to concurrent I/O on a versioned bucket it can lead
to loss of versions.
This PR fixes this bug with multi-pool setup with replication
that causes corruption of inlined data due to lack of competing
locks in a multi-pool setup.
Instead CompleteMultipartUpload holds the necessary
locks when finishing the transaction, knowing the exact
location of an object to schedule the multipart upload
doesn't need to compete in this manner, a pool id location
for existing object.
A multi resources lock is a single lock UID with multiple associated
resources. This is created for example by multi objects delete
operation. This commit changes the behavior of Refresh() to iterate over
all locks having the same UID and refresh them.
Bonus: Fix showing top locks for multi delete objects
In the event when a lock is not refreshed in the cluster, this latter
will be automatically removed in the subsequent cleanup of non
refreshed locks routine, but it forgot to clean the local server,
hence having the same weird stale locks present.
This commit will remove the lock locally also in remote nodes, if
removing a lock from a remote node will fail, it will be anyway
removed later in the locks cleanup routine.
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`
Harshavardhana
Frank Wessels
Klaus Post
Aditya Manthramurthy
Anis Eleuch
LHHDZ