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
|
package s3api
import (
"fmt"
"github.com/chrislusf/seaweedfs/weed/filer"
"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/s3_pb"
"github.com/chrislusf/seaweedfs/weed/s3api/s3_constants"
"github.com/chrislusf/seaweedfs/weed/s3api/s3err"
"github.com/gorilla/mux"
"net/http"
"sync"
"sync/atomic"
)
type CircuitBreaker struct {
sync.RWMutex
Enabled bool
counters map[string]*int64
limitations map[string]int64
}
func NewCircuitBreaker(option *S3ApiServerOption) *CircuitBreaker {
cb := &CircuitBreaker{
counters: make(map[string]*int64),
limitations: make(map[string]int64),
}
err := pb.WithFilerClient(false, option.Filer, option.GrpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
content, err := filer.ReadInsideFiler(client, s3_constants.CircuitBreakerConfigDir, s3_constants.CircuitBreakerConfigFile)
if err != nil {
return fmt.Errorf("read S3 circuit breaker config: %v", err)
}
return cb.LoadS3ApiConfigurationFromBytes(content)
})
if err != nil {
glog.Infof("s3 circuit breaker not configured: %v", err)
}
return cb
}
func (cb *CircuitBreaker) LoadS3ApiConfigurationFromBytes(content []byte) error {
cbCfg := &s3_pb.S3CircuitBreakerConfig{}
if err := filer.ParseS3ConfigurationFromBytes(content, cbCfg); err != nil {
glog.Warningf("unmarshal error: %v", err)
return fmt.Errorf("unmarshal error: %v", err)
}
if err := cb.loadCircuitBreakerConfig(cbCfg); err != nil {
return err
}
return nil
}
func (cb *CircuitBreaker) loadCircuitBreakerConfig(cfg *s3_pb.S3CircuitBreakerConfig) error {
//global
globalEnabled := false
globalOptions := cfg.Global
limitations := make(map[string]int64)
if globalOptions != nil && globalOptions.Enabled && len(globalOptions.Actions) > 0 {
globalEnabled = globalOptions.Enabled
for action, limit := range globalOptions.Actions {
limitations[action] = limit
}
}
cb.Enabled = globalEnabled
//buckets
for bucket, cbOptions := range cfg.Buckets {
if cbOptions.Enabled {
for action, limit := range cbOptions.Actions {
limitations[s3_constants.Concat(bucket, action)] = limit
}
}
}
cb.limitations = limitations
return nil
}
func (cb *CircuitBreaker) Limit(f func(w http.ResponseWriter, r *http.Request), action string) (http.HandlerFunc, Action) {
return func(w http.ResponseWriter, r *http.Request) {
if !cb.Enabled {
f(w, r)
return
}
vars := mux.Vars(r)
bucket := vars["bucket"]
rollback, errCode := cb.limit(r, bucket, action)
defer func() {
for _, rf := range rollback {
rf()
}
}()
if errCode == s3err.ErrNone {
f(w, r)
return
}
s3err.WriteErrorResponse(w, r, errCode)
}, Action(action)
}
func (cb *CircuitBreaker) limit(r *http.Request, bucket string, action string) (rollback []func(), errCode s3err.ErrorCode) {
//bucket simultaneous request count
bucketCountRollBack, errCode := cb.loadCounterAndCompare(s3_constants.Concat(bucket, action, s3_constants.LimitTypeCount), 1, s3err.ErrTooManyRequest)
if bucketCountRollBack != nil {
rollback = append(rollback, bucketCountRollBack)
}
if errCode != s3err.ErrNone {
return
}
//bucket simultaneous request content bytes
bucketContentLengthRollBack, errCode := cb.loadCounterAndCompare(s3_constants.Concat(bucket, action, s3_constants.LimitTypeBytes), r.ContentLength, s3err.ErrRequestBytesExceed)
if bucketContentLengthRollBack != nil {
rollback = append(rollback, bucketContentLengthRollBack)
}
if errCode != s3err.ErrNone {
return
}
//global simultaneous request count
globalCountRollBack, errCode := cb.loadCounterAndCompare(s3_constants.Concat(action, s3_constants.LimitTypeCount), 1, s3err.ErrTooManyRequest)
if globalCountRollBack != nil {
rollback = append(rollback, globalCountRollBack)
}
if errCode != s3err.ErrNone {
return
}
//global simultaneous request content bytes
globalContentLengthRollBack, errCode := cb.loadCounterAndCompare(s3_constants.Concat(action, s3_constants.LimitTypeBytes), r.ContentLength, s3err.ErrRequestBytesExceed)
if globalContentLengthRollBack != nil {
rollback = append(rollback, globalContentLengthRollBack)
}
if errCode != s3err.ErrNone {
return
}
return
}
func (cb *CircuitBreaker) loadCounterAndCompare(key string, inc int64, errCode s3err.ErrorCode) (f func(), e s3err.ErrorCode) {
e = s3err.ErrNone
if max, ok := cb.limitations[key]; ok {
cb.RLock()
counter, exists := cb.counters[key]
cb.RUnlock()
if !exists {
cb.Lock()
counter, exists = cb.counters[key]
if !exists {
var newCounter int64
counter = &newCounter
cb.counters[key] = counter
}
cb.Unlock()
}
current := atomic.LoadInt64(counter)
if current+inc > max {
e = errCode
return
} else {
current := atomic.AddInt64(counter, inc)
f = func() {
atomic.AddInt64(counter, -inc)
}
if current > max {
e = errCode
return
}
}
}
return
}
|
