1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
package weed_server
import (
"context"
"fmt"
"github.com/chrislusf/seaweedfs/weed/cluster"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/pb"
"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
"github.com/chrislusf/seaweedfs/weed/pb/volume_server_pb"
"math/rand"
"sync"
"time"
"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
)
/*
How exclusive lock works?
-----------
Shell
------
When shell lock,
* lease an admin token (lockTime, token)
* start a goroutine to renew the admin token periodically
When shell unlock
* stop the renewal goroutine
* sends a release lock request
Master
------
Master maintains:
* randomNumber
* lastLockTime
When master receives the lease/renew request from shell
If lastLockTime still fresh {
if is a renew and token is valid {
// for renew
generate the randomNumber => token
return
}
refuse
return
} else {
// for fresh lease request
generate the randomNumber => token
return
}
When master receives the release lock request from shell
set the lastLockTime to zero
The volume server does not need to verify.
This makes the lock/unlock optional, similar to what golang code usually does.
*/
const (
LockDuration = 10 * time.Second
)
type AdminLock struct {
accessSecret int64
accessLockTime time.Time
lastClient string
lastMessage string
}
type AdminLocks struct {
locks map[string]*AdminLock
sync.RWMutex
}
func NewAdminLocks() *AdminLocks {
return &AdminLocks{
locks: make(map[string]*AdminLock),
}
}
func (locks *AdminLocks) isLocked(lockName string) (clientName string, message string, isLocked bool) {
locks.RLock()
defer locks.RUnlock()
adminLock, found := locks.locks[lockName]
if !found {
return "", "", false
}
glog.V(4).Infof("isLocked %v: %v", adminLock.lastClient, adminLock.lastMessage)
return adminLock.lastClient, adminLock.lastMessage, adminLock.accessLockTime.Add(LockDuration).After(time.Now())
}
func (locks *AdminLocks) isValidToken(lockName string, ts time.Time, token int64) bool {
locks.RLock()
defer locks.RUnlock()
adminLock, found := locks.locks[lockName]
if !found {
return false
}
return adminLock.accessLockTime.Equal(ts) && adminLock.accessSecret == token
}
func (locks *AdminLocks) generateToken(lockName string, clientName string) (ts time.Time, token int64) {
locks.Lock()
defer locks.Unlock()
lock := &AdminLock{
accessSecret: rand.Int63(),
accessLockTime: time.Now(),
lastClient: clientName,
}
locks.locks[lockName] = lock
return lock.accessLockTime, lock.accessSecret
}
func (locks *AdminLocks) deleteLock(lockName string) {
locks.Lock()
defer locks.Unlock()
delete(locks.locks, lockName)
}
func (ms *MasterServer) LeaseAdminToken(ctx context.Context, req *master_pb.LeaseAdminTokenRequest) (*master_pb.LeaseAdminTokenResponse, error) {
resp := &master_pb.LeaseAdminTokenResponse{}
if lastClient, lastMessage, isLocked := ms.adminLocks.isLocked(req.LockName); isLocked {
glog.V(4).Infof("LeaseAdminToken %v", lastClient)
if req.PreviousToken != 0 && ms.adminLocks.isValidToken(req.LockName, time.Unix(0, req.PreviousLockTime), req.PreviousToken) {
// for renew
ts, token := ms.adminLocks.generateToken(req.LockName, req.ClientName)
resp.Token, resp.LockTsNs = token, ts.UnixNano()
return resp, nil
}
// refuse since still locked
return resp, fmt.Errorf("already locked by %v: %v", lastClient, lastMessage)
}
// for fresh lease request
ts, token := ms.adminLocks.generateToken(req.LockName, req.ClientName)
resp.Token, resp.LockTsNs = token, ts.UnixNano()
return resp, nil
}
func (ms *MasterServer) ReleaseAdminToken(ctx context.Context, req *master_pb.ReleaseAdminTokenRequest) (*master_pb.ReleaseAdminTokenResponse, error) {
resp := &master_pb.ReleaseAdminTokenResponse{}
if ms.adminLocks.isValidToken(req.LockName, time.Unix(0, req.PreviousLockTime), req.PreviousToken) {
ms.adminLocks.deleteLock(req.LockName)
}
return resp, nil
}
func (ms *MasterServer) Ping(ctx context.Context, req *master_pb.PingRequest) (resp *master_pb.PingResponse, pingErr error) {
resp = &master_pb.PingResponse{
StartTimeNs: time.Now().UnixNano(),
}
if req.TargetType == cluster.FilerType {
pingErr = pb.WithFilerClient(false, pb.ServerAddress(req.Target), ms.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
pingResp, err := client.Ping(ctx, &filer_pb.PingRequest{})
if pingResp != nil {
resp.RemoteTimeNs = pingResp.StartTimeNs
}
return err
})
}
if req.TargetType == cluster.VolumeServerType {
pingErr = pb.WithVolumeServerClient(false, pb.ServerAddress(req.Target), ms.grpcDialOption, func(client volume_server_pb.VolumeServerClient) error {
pingResp, err := client.Ping(ctx, &volume_server_pb.PingRequest{})
if pingResp != nil {
resp.RemoteTimeNs = pingResp.StartTimeNs
}
return err
})
}
if req.TargetType == cluster.MasterType {
pingErr = pb.WithMasterClient(false, pb.ServerAddress(req.Target), ms.grpcDialOption, func(client master_pb.SeaweedClient) error {
pingResp, err := client.Ping(ctx, &master_pb.PingRequest{})
if pingResp != nil {
resp.RemoteTimeNs = pingResp.StartTimeNs
}
return err
})
}
if pingErr != nil {
pingErr = fmt.Errorf("ping %s %s: %v", req.TargetType, req.Target, pingErr)
}
resp.StopTimeNs = time.Now().UnixNano()
return
}
|
