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.
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.
When limiting listing do not count delete, since they may be discarded.
Extend limit, since we may be discarding the forward-to marker.
Fix directories always being sent to resolve, since they didn't return as match.
The main goal of this PR is to solve the situation where disks stop
responding to operations. This generally causes an FD build-up and
eventually will crash the server.
This adds detection of hung disks, where calls on disk get stuck.
We add functionality to `xlStorageDiskIDCheck` where it keeps
track of the number of concurrent requests on a given disk.
A total number of 100 operations are allowed. If this limit is reached
we will block (but not reject) new requests, but we will monitor the
state of the disk.
If no requests have been completed or updated within a 15-second
window, we mark the disk as offline. Requests that are blocked will be
unblocked and return an error as "faulty disk".
New requests will be rejected until the disk is marked OK again.
Once a disk has been marked faulty, a check will run every 5 seconds that
will attempt to write and read back a file. As long as this fails the disk will
remain faulty.
To prevent lots of long-running requests to mark the disk faulty we
implement a callback feature that allows updating the status as parts
of these operations are running.
We add a reader and writer wrapper that will update the status of each
successful read/write operation. This should allow fine enough granularity
that a slow, but still operational disk will not reach 15 seconds where
50 operations have not progressed.
Note that errors themselves are not enough to mark a disk faulty.
A nil (or io.EOF) error will mark a disk as "good".
* Make concurrent disk setting configurable via `_MINIO_DISK_MAX_CONCURRENT`.
* de-couple IsOnline() from disk health tracker
The purpose of IsOnline() is to ensure that we
reconnect the drive only when the "drive" was
- disconnected from network we need to validate
if the drive is "correct" and is the same drive
which belongs to this server.
- drive was replaced we have to format it - we
support hot swapping of the drives.
IsOnline() is not meant for taking the drive offline
when it is hung, it is not useful we can let the
drive be online instead "return" errors for relevant
calls.
* return errFaultyDisk for DiskInfo() call
Co-authored-by: Harshavardhana <harsha@minio.io>
Possible future Improvements:
* Unify the REST server and local xlStorageDiskIDCheck. This would also improve stats significantly.
* Allow reads/writes to be aborted by the context.
* Add usage stats, concurrent count, blocked operations, etc.
request.Form uses less memory allocation and avoids gorilla mux matching
with weird characters in parameters such as '\n'
- Remove Queries() to avoid matching
- Ensure r.ParseForm is called to populate fields
- Add a unit test for object names with '\n'
On first list resume or when specifying a custom markers entries could be missed in rare cases.
Do conservative truncation of entries when forwarding.
Replaces #13619
once we have competed for locks, verify if the
context is still valid - this is to ensure that
we do not start readdir() or read() calls on the
drives on canceled connections.
This commit brings two locks instead of single lock for
WalkDir() calls on top of c25816eabc.
The main reason is to avoid contention between readMetadata()
and ListDir() calls, ListDir() can take time on prefixes that
are huge for readdir() but this shouldn't end up blocking
all readMetadata() operations, this allows for more room for
I/O while not overly penalizing all listing operations.
Objects uploaded in this format for example
```
mc cp /etc/hosts alias/bucket/foo/bar/xl.meta
mc ls -r alias/bucket/foo/bar
```
Won't list the object, handle this scenario.
We are observing heavy system loads, potentially
locking the system up for periods when concurrent
listing operations are performed.
We place a per-disk lock on walk IO operations.
This will minimize the impact of concurrent listing
operations on the entire system and de-prioritize
them compared to other operations.
Single list operations should remain largely unaffected.
Some applications albeit poorly written rather than using headObject
rely on listObjects to check for existence of object, this unusual
request always has prefix=(to actual object) and max-keys=1
handle this situation specially such that we can avoid readdir()
on the top level parent to avoid sorting and skipping, ensuring
that such type of listObjects() always behaves similar to a
headObject() call.
this addresses a regression from #12984
which only addresses flat key from single
level deep at bucket level.
added extra tests as well to cover all
these scenarios.
baseDir is empty if the top level prefix does not
end with `/` this causes large recursive listings
without any filtering, to fix this filtering make
sure to set the filter prefix appropriately.
also do not navigate folders at top level that do
not match the filter prefix, entries don't need
to match prefix since they are never prefixed
with the prefix anyways.
- remove use of getOnlineDisks() instead rely on fallbackDisks()
when disk return errors like diskNotFound, unformattedDisk
use other fallback disks to list from, instead of paying the
price for checking getOnlineDisks()
- optimize getDiskID() further to avoid large write locks when
looking formatLastCheck time window
This new change allows for a more relaxed fallback for listing
allowing for more tolerance and also eventually gain more
consistency in results even if using '3' disks by default.
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`
Previous PR #12351 added functions to read from the reader
stream to reduce memory usage, use the same technique in
few other places where we are not interested in reading the
data part.
In #11888 we observe a lot of running, WalkDir calls.
There doesn't appear to be any listerners for these calls, so they should be aborted.
Ensure that WalkDir aborts when upstream cancels the request.
Fixes#11888
```
mc admin info --json
```
provides these details, for now, we shall eventually
expose this at Prometheus level eventually.
Co-authored-by: Harshavardhana <harsha@minio.io>
Instead of using O_SYNC, we are better off using O_DSYNC
instead since we are only ever interested in data to be
persisted to disk not the associated filesystem metadata.
For reads we ask customers to turn off noatime, but instead
we can proactively use O_NOATIME flag to avoid atime updates
upon reads.
When a directory object is presented as a `prefix`
param our implementation tend to only list objects
present common to the `prefix` than the `prefix` itself,
to mimic AWS S3 like flat key behavior this PR ensures
that if `prefix` is directory object, it should be
automatically considered to be part of the eventual
listing result.
fixes#11370
```
minio server /tmp/disk{1...4}
mc mb myminio/testbucket/
mkdir -p /tmp/disk{1..4}/testbucket/test-prefix/
```
This would end up being listed in the current
master, this PR fixes this situation.
If a directory is a leaf dir we should it
being listed, since it cannot be deleted anymore
with DeleteObject, DeleteObjects() API calls
because we natively support directories now.
Avoid listing it and let healing purge this folder
eventually in the background.
Fixes two problems
- Double healing when bitrot is enabled, instead heal attempt
once in applyActions() before lifecycle is applied.
- If applyActions() is successful and getSize() returns proper
value, then object is accounted for and should be removed
from the oldCache namespace map to avoid double heal attempts.
Klaus Post
Maxim Tkachenko
Harshavardhana
Kaan Kabalak
Anis Elleuch