forked from vitessio/vitess
/
serving_graph.go
291 lines (256 loc) · 7.82 KB
/
serving_graph.go
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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
// Copyright 2013, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package zktopo
import (
"encoding/json"
"fmt"
"path"
"sort"
"time"
log "github.com/golang/glog"
"golang.org/x/net/context"
"launchpad.net/gozk/zookeeper"
"github.com/youtube/vitess/go/vt/topo"
"github.com/youtube/vitess/go/zk"
topodatapb "github.com/youtube/vitess/go/vt/proto/topodata"
vschemapb "github.com/youtube/vitess/go/vt/proto/vschema"
)
// WatchSleepDuration is how many seconds interval to poll for in case
// the directory that contains a file to watch doesn't exist, or a watch
// is broken. It is exported so individual test and main programs
// can change it.
var WatchSleepDuration = 30 * time.Second
/*
This file contains the serving graph management code of zktopo.Server
*/
func zkPathForCell(cell string) string {
return fmt.Sprintf("/zk/%v/vt", cell)
}
func zkPathForSrvKeyspaces(cell string) string {
return path.Join(zkPathForCell(cell), "ns")
}
func zkPathForSrvKeyspace(cell, keyspace string) string {
return path.Join(zkPathForSrvKeyspaces(cell), keyspace)
}
func zkPathForSrvVSchema(cell string) string {
return path.Join(zkPathForCell(cell), "vschema")
}
// GetSrvKeyspaceNames is part of the topo.Server interface
func (zkts *Server) GetSrvKeyspaceNames(ctx context.Context, cell string) ([]string, error) {
children, _, err := zkts.zconn.Children(zkPathForSrvKeyspaces(cell))
if err != nil {
err = convertError(err)
if err == topo.ErrNoNode {
return nil, nil
}
return nil, err
}
sort.Strings(children)
return children, nil
}
// WatchSrvKeyspace is part of the topo.Server interface
func (zkts *Server) WatchSrvKeyspace(ctx context.Context, cell, keyspace string) (<-chan *topodatapb.SrvKeyspace, error) {
filePath := zkPathForSrvKeyspace(cell, keyspace)
notifications := make(chan *topodatapb.SrvKeyspace, 10)
// waitOrInterrupted will return true if context.Done() is triggered
waitOrInterrupted := func() bool {
timer := time.After(WatchSleepDuration)
select {
case <-ctx.Done():
close(notifications)
return true
case <-timer:
}
return false
}
go func() {
for {
// set the watch
data, _, watch, err := zkts.zconn.GetW(filePath)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
// the parent directory doesn't exist
notifications <- nil
}
log.Errorf("Cannot set watch on %v, waiting for %v to retry: %v", filePath, WatchSleepDuration, err)
if waitOrInterrupted() {
return
}
continue
}
// get the initial value, send it, or send nil if no
// data
var srvKeyspace *topodatapb.SrvKeyspace
sendIt := true
if len(data) > 0 {
srvKeyspace = &topodatapb.SrvKeyspace{}
if err := json.Unmarshal([]byte(data), srvKeyspace); err != nil {
log.Errorf("SrvKeyspace unmarshal failed: %v %v", data, err)
sendIt = false
}
}
if sendIt {
notifications <- srvKeyspace
}
// now act on the watch
select {
case event, ok := <-watch:
if !ok {
log.Warningf("watch on %v was closed, waiting for %v to retry", filePath, WatchSleepDuration)
if waitOrInterrupted() {
return
}
continue
}
if !event.Ok() {
log.Warningf("received a non-OK event for %v, waiting for %v to retry", filePath, WatchSleepDuration)
if waitOrInterrupted() {
return
}
}
case <-ctx.Done():
// user is not interested any more
close(notifications)
return
}
}
}()
return notifications, nil
}
// UpdateSrvKeyspace is part of the topo.Server interface
func (zkts *Server) UpdateSrvKeyspace(ctx context.Context, cell, keyspace string, srvKeyspace *topodatapb.SrvKeyspace) error {
path := zkPathForSrvKeyspace(cell, keyspace)
data, err := json.MarshalIndent(srvKeyspace, "", " ")
if err != nil {
return err
}
_, err = zkts.zconn.Set(path, string(data), -1)
if zookeeper.IsError(err, zookeeper.ZNONODE) {
_, err = zk.CreateRecursive(zkts.zconn, path, string(data), 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
}
return convertError(err)
}
// DeleteSrvKeyspace is part of the topo.Server interface
func (zkts *Server) DeleteSrvKeyspace(ctx context.Context, cell, keyspace string) error {
path := zkPathForSrvKeyspace(cell, keyspace)
err := zkts.zconn.Delete(path, -1)
if err != nil {
return convertError(err)
}
return nil
}
// GetSrvKeyspace is part of the topo.Server interface
func (zkts *Server) GetSrvKeyspace(ctx context.Context, cell, keyspace string) (*topodatapb.SrvKeyspace, error) {
path := zkPathForSrvKeyspace(cell, keyspace)
data, _, err := zkts.zconn.Get(path)
if err != nil {
return nil, convertError(err)
}
if len(data) == 0 {
return nil, topo.ErrNoNode
}
srvKeyspace := &topodatapb.SrvKeyspace{}
if err := json.Unmarshal([]byte(data), srvKeyspace); err != nil {
return nil, fmt.Errorf("SrvKeyspace unmarshal failed: %v %v", data, err)
}
return srvKeyspace, nil
}
// WatchSrvVSchema is part of the topo.Server interface
func (zkts *Server) WatchSrvVSchema(ctx context.Context, cell string) (<-chan *vschemapb.SrvVSchema, error) {
filePath := zkPathForSrvVSchema(cell)
notifications := make(chan *vschemapb.SrvVSchema, 10)
// waitOrInterrupted will return true if context.Done() is triggered
waitOrInterrupted := func() bool {
timer := time.After(WatchSleepDuration)
select {
case <-ctx.Done():
close(notifications)
return true
case <-timer:
}
return false
}
go func() {
for {
// set the watch
data, _, watch, err := zkts.zconn.GetW(filePath)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
// the parent directory doesn't exist
notifications <- nil
}
log.Errorf("Cannot set watch on %v, waiting for %v to retry: %v", filePath, WatchSleepDuration, err)
if waitOrInterrupted() {
return
}
continue
}
// get the initial value, send it, or send nil if no
// data
var srvVSchema *vschemapb.SrvVSchema
sendIt := true
if len(data) > 0 {
srvVSchema = &vschemapb.SrvVSchema{}
if err := json.Unmarshal([]byte(data), srvVSchema); err != nil {
log.Errorf("SrvVSchema unmarshal failed: %v %v", data, err)
sendIt = false
}
}
if sendIt {
notifications <- srvVSchema
}
// now act on the watch
select {
case event, ok := <-watch:
if !ok {
log.Warningf("watch on %v was closed, waiting for %v to retry", filePath, WatchSleepDuration)
if waitOrInterrupted() {
return
}
continue
}
if !event.Ok() {
log.Warningf("received a non-OK event for %v, waiting for %v to retry", filePath, WatchSleepDuration)
if waitOrInterrupted() {
return
}
}
case <-ctx.Done():
// user is not interested any more
close(notifications)
return
}
}
}()
return notifications, nil
}
// UpdateSrvVSchema is part of the topo.Server interface
func (zkts *Server) UpdateSrvVSchema(ctx context.Context, cell string, srvVSchema *vschemapb.SrvVSchema) error {
path := zkPathForSrvVSchema(cell)
data, err := json.MarshalIndent(srvVSchema, "", " ")
if err != nil {
return err
}
_, err = zkts.zconn.Set(path, string(data), -1)
if zookeeper.IsError(err, zookeeper.ZNONODE) {
_, err = zk.CreateRecursive(zkts.zconn, path, string(data), 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
}
return convertError(err)
}
// GetSrvVSchema is part of the topo.Server interface
func (zkts *Server) GetSrvVSchema(ctx context.Context, cell string) (*vschemapb.SrvVSchema, error) {
path := zkPathForSrvVSchema(cell)
data, _, err := zkts.zconn.Get(path)
if err != nil {
return nil, convertError(err)
}
if len(data) == 0 {
return nil, topo.ErrNoNode
}
srvVSchema := &vschemapb.SrvVSchema{}
if err := json.Unmarshal([]byte(data), srvVSchema); err != nil {
return nil, fmt.Errorf("SrvVSchema unmarshal failed: %v %v", data, err)
}
return srvVSchema, nil
}