minio/cmd/lock-rest-client.go
Harshavardhana e9b2bf00ad Support MinIO to be deployed on more than 32 nodes (#8492)
This PR implements locking from a global entity into
a more localized set level entity, allowing for locks
to be held only on the resources which are writing
to a collection of disks rather than a global level.

In this process this PR also removes the top-level
limit of 32 nodes to an unlimited number of nodes. This
is a precursor change before bring in bucket expansion.
2019-11-13 12:17:45 -08:00

178 lines
4.7 KiB
Go

/*
* MinIO Cloud Storage, (C) 2019 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"context"
"crypto/tls"
"errors"
"io"
"sync/atomic"
"time"
"net/url"
"github.com/minio/minio/cmd/http"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/cmd/rest"
"github.com/minio/minio/pkg/dsync"
)
// lockRESTClient is authenticable lock REST client
type lockRESTClient struct {
restClient *rest.Client
endpoint Endpoint
connected int32
}
func toLockError(err error) error {
if err == nil {
return nil
}
switch err.Error() {
case errLockConflict.Error():
return errLockConflict
}
return err
}
// String stringer *dsync.NetLocker* interface compatible method.
func (client *lockRESTClient) String() string {
return client.endpoint.String()
}
// Wrapper to restClient.Call to handle network errors, in case of network error the connection is marked disconnected
// permanently. The only way to restore the connection is at the xl-sets layer by xlsets.monitorAndConnectEndpoints()
// after verifying format.json
func (client *lockRESTClient) call(method string, values url.Values, body io.Reader, length int64) (respBody io.ReadCloser, err error) {
if !client.IsOnline() {
return nil, errors.New("Lock rest server node is down")
}
if values == nil {
values = make(url.Values)
}
respBody, err = client.restClient.Call(method, values, body, length)
if err == nil {
return respBody, nil
}
if isNetworkError(err) {
time.AfterFunc(defaultRetryUnit*3, func() {
// After 3 seconds, take this lock client online for a retry.
atomic.StoreInt32(&client.connected, 1)
})
atomic.StoreInt32(&client.connected, 0)
}
return nil, toLockError(err)
}
// IsOnline - returns whether REST client failed to connect or not.
func (client *lockRESTClient) IsOnline() bool {
return atomic.LoadInt32(&client.connected) == 1
}
// Close - marks the client as closed.
func (client *lockRESTClient) Close() error {
atomic.StoreInt32(&client.connected, 0)
client.restClient.Close()
return nil
}
// restCall makes a call to the lock REST server.
func (client *lockRESTClient) restCall(call string, args dsync.LockArgs) (reply bool, err error) {
values := url.Values{}
values.Set(lockRESTUID, args.UID)
values.Set(lockRESTSource, args.Source)
values.Set(lockRESTResource, args.Resource)
respBody, err := client.call(call, values, nil, -1)
defer http.DrainBody(respBody)
switch err {
case nil:
return true, nil
case errLockConflict:
return false, nil
default:
return false, err
}
}
// RLock calls read lock REST API.
func (client *lockRESTClient) RLock(args dsync.LockArgs) (reply bool, err error) {
return client.restCall(lockRESTMethodRLock, args)
}
// Lock calls lock REST API.
func (client *lockRESTClient) Lock(args dsync.LockArgs) (reply bool, err error) {
return client.restCall(lockRESTMethodLock, args)
}
// RUnlock calls read unlock REST API.
func (client *lockRESTClient) RUnlock(args dsync.LockArgs) (reply bool, err error) {
return client.restCall(lockRESTMethodRUnlock, args)
}
// Unlock calls write unlock RPC.
func (client *lockRESTClient) Unlock(args dsync.LockArgs) (reply bool, err error) {
return client.restCall(lockRESTMethodUnlock, args)
}
func closeLockers(lockers []dsync.NetLocker) {
for _, locker := range lockers {
locker.Close()
}
}
func newLockAPI(endpoint Endpoint) dsync.NetLocker {
if endpoint.IsLocal {
return globalLockServers[endpoint]
}
return newlockRESTClient(endpoint)
}
// Returns a lock rest client.
func newlockRESTClient(endpoint Endpoint) *lockRESTClient {
serverURL := &url.URL{
Scheme: endpoint.Scheme,
Host: endpoint.Host,
Path: pathJoin(lockRESTPrefix, endpoint.Path, lockRESTVersion),
}
var tlsConfig *tls.Config
if globalIsSSL {
tlsConfig = &tls.Config{
ServerName: endpoint.Hostname(),
RootCAs: globalRootCAs,
NextProtos: []string{"http/1.1"}, // Force http1.1
}
}
trFn := newCustomHTTPTransport(tlsConfig, rest.DefaultRESTTimeout, rest.DefaultRESTTimeout)
restClient, err := rest.NewClient(serverURL, trFn, newAuthToken)
if err != nil {
logger.LogIf(context.Background(), err)
return &lockRESTClient{endpoint: endpoint, restClient: restClient, connected: 0}
}
return &lockRESTClient{endpoint: endpoint, restClient: restClient, connected: 1}
}