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
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
|
/**
* 支持失败重试的 FailbackRegistry抽象类
*/
public abstract class FailbackRegistry extends AbstractRegistry {
/**
* 定时任务执行器
*/
private final ScheduledExecutorService retryExecutor = Executors.
newScheduledThreadPool(1, new NamedThreadFactory("DubboRegistryFailedRetryTimer", true));
/**
* 失败重试定时器，定时检查是否有请求失败，如有，无限次重试
*/
private final ScheduledFuture<?> retryFuture;
/**
* 注册失败的 URL 集合
*/
private final Set<URL> failedRegistered = new ConcurrentHashSet<URL>();
/**
* 取消注册失败的 URL 集合
*/
private final Set<URL> failedUnregistered = new ConcurrentHashSet<URL>();
/**
* 订阅失败的监听器集合
*/
private final ConcurrentMap<URL, Set<NotifyListener>> failedSubscribed = new ConcurrentHashMap<URL, Set<NotifyListener>>();
/**
* 取消订阅失败的监听器集合
*/
private final ConcurrentMap<URL, Set<NotifyListener>> failedUnsubscribed = new ConcurrentHashMap<URL, Set<NotifyListener>>();
/**
* 通知失败的 URL 集合
*/
private final ConcurrentMap<URL, Map<NotifyListener, List<URL>>> failedNotified = new ConcurrentHashMap<URL, Map<NotifyListener, List<URL>>>();
/**
* 是否销毁
*/
private AtomicBoolean destroyed = new AtomicBoolean(false);
public FailbackRegistry(URL url) {
super(url);
// 重试频率，单位：毫秒
int retryPeriod = url.getParameter(Constants.REGISTRY_RETRY_PERIOD_KEY, Constants.DEFAULT_REGISTRY_RETRY_PERIOD);
// 创建失败重试定时器
this.retryFuture = retryExecutor.scheduleWithFixedDelay(new Runnable() {
public void run() {
// Check and connect to the registry
try {
retry();
} catch (Throwable t) { // Defensive fault tolerance
logger.error("Unexpected error occur at failed retry, cause: " + t.getMessage(), t);
}
}
}, retryPeriod, retryPeriod, TimeUnit.MILLISECONDS);
}
public Future<?> getRetryFuture() {
return retryFuture;
}
public Set<URL> getFailedRegistered() {
return failedRegistered;
}
public Set<URL> getFailedUnregistered() {
return failedUnregistered;
}
public Map<URL, Set<NotifyListener>> getFailedSubscribed() {
return failedSubscribed;
}
public Map<URL, Set<NotifyListener>> getFailedUnsubscribed() {
return failedUnsubscribed;
}
public Map<URL, Map<NotifyListener, List<URL>>> getFailedNotified() {
return failedNotified;
}
/**
* 添加到 `failedSubscribed`
*/
private void addFailedSubscribed(URL url, NotifyListener listener) {
Set<NotifyListener> listeners = failedSubscribed.get(url);
if (listeners == null) {
failedSubscribed.putIfAbsent(url, new ConcurrentHashSet<NotifyListener>());
listeners = failedSubscribed.get(url);
}
listeners.add(listener);
}
/**
* 移除出 `failedSubscribed` `failedUnsubscribed` `failedNotified`
*/
private void removeFailedSubscribed(URL url, NotifyListener listener) {
// 移除出 `failedSubscribed`
Set<NotifyListener> listeners = failedSubscribed.get(url);
if (listeners != null) {
listeners.remove(listener);
}
// 移除出 `failedUnsubscribed`
listeners = failedUnsubscribed.get(url);
if (listeners != null) {
listeners.remove(listener);
}
// 移除出 `failedNotified`
Map<NotifyListener, List<URL>> notified = failedNotified.get(url);
if (notified != null) {
notified.remove(listener);
}
}
@Override
public void register(URL url) {
// 已销毁，跳过
if (destroyed.get()){
return;
}
// 添加到 `registered` 变量
super.register(url);
// 移除出 `failedRegistered` `failedUnregistered` 变量
failedRegistered.remove(url);
failedUnregistered.remove(url);
// 向注册中心发送注册请求
try {
doRegister(url);
} catch (Exception e) {
Throwable t = e;
// 如果开启了启动时检测，则直接抛出异常
boolean check = getUrl().getParameter(Constants.CHECK_KEY, true)
&& url.getParameter(Constants.CHECK_KEY, true)
&& !Constants.CONSUMER_PROTOCOL.equals(url.getProtocol()); // 非消费者。消费者会在 `ReferenceConfig#createProxy(...)` 方法中，调用 `Invoker#avalible()` 方法，进行检查。
boolean skipFailback = t instanceof SkipFailbackWrapperException;
if (check || skipFailback) {
if (skipFailback) {
t = t.getCause();
}
throw new IllegalStateException("Failed to register " + url + " to registry " + getUrl().getAddress() + ", cause: " + t.getMessage(), t);
} else {
logger.error("Failed to register " + url + ", waiting for retry, cause: " + t.getMessage(), t);
}
// 将失败的注册请求记录到 `failedRegistered`，定时重试
failedRegistered.add(url);
}
}
@Override
public void unregister(URL url) {
// 已销毁，跳过
if (destroyed.get()){
return;
}
// 移除出 `registered` 变量
super.unregister(url);
// 移除出 `failedRegistered` `failedUnregistered` 变量
failedRegistered.remove(url);
failedUnregistered.remove(url);
// 向注册中心发送取消注册请求
try {
doUnregister(url);
} catch (Exception e) {
Throwable t = e;
// 如果开启了启动时检测，则直接抛出异常
boolean check = getUrl().getParameter(Constants.CHECK_KEY, true)
&& url.getParameter(Constants.CHECK_KEY, true)
&& !Constants.CONSUMER_PROTOCOL.equals(url.getProtocol());
boolean skipFailback = t instanceof SkipFailbackWrapperException;
if (check || skipFailback) {
if (skipFailback) {
t = t.getCause();
}
throw new IllegalStateException("Failed to unregister " + url + " to registry " + getUrl().getAddress() + ", cause: " + t.getMessage(), t);
} else {
logger.error("Failed to uregister " + url + ", waiting for retry, cause: " + t.getMessage(), t);
}
// 将失败的取消注册请求记录到 `failedUnregistered`，定时重试
failedUnregistered.add(url);
}
}
@Override
public void subscribe(URL url, NotifyListener listener) {
// 已销毁，跳过
if (destroyed.get()){
return;
}
// 移除出 `subscribed` 变量
super.subscribe(url, listener);
// 移除出 `failedSubscribed` `failedUnsubscribed` `failedNotified`
removeFailedSubscribed(url, listener);
// 向注册中心发送订阅请求
try {
doSubscribe(url, listener);
} catch (Exception e) {
Throwable t = e;
// 如果有缓存的 URL 集合，进行通知。后续订阅成功后，会使用最新的 URL 集合，进行通知。
List<URL> urls = getCacheUrls(url);
if (urls != null && !urls.isEmpty()) {
notify(url, listener, urls);
logger.error("Failed to subscribe " + url + ", Using cached list: " + urls + " from cache file: " + getUrl().getParameter(Constants.FILE_KEY, System.getProperty("user.home") + "/dubbo-registry-" + url.getHost() + ".cache") + ", cause: " + t.getMessage(), t);
} else {
// 如果开启了启动时检测，则直接抛出异常
// If the startup detection is opened, the Exception is thrown directly.
boolean check = getUrl().getParameter(Constants.CHECK_KEY, true)
&& url.getParameter(Constants.CHECK_KEY, true);
boolean skipFailback = t instanceof SkipFailbackWrapperException;
if (check || skipFailback) {
if (skipFailback) {
t = t.getCause();
}
throw new IllegalStateException("Failed to subscribe " + url + ", cause: " + t.getMessage(), t);
} else {
logger.error("Failed to subscribe " + url + ", waiting for retry, cause: " + t.getMessage(), t);
}
}
// 将失败的订阅请求记录到 `failedSubscribed`，定时重试
// Record a failed registration request to a failed list, retry regularly
addFailedSubscribed(url, listener);
}
}
@Override
public void unsubscribe(URL url, NotifyListener listener) {
// 已销毁，跳过
if (destroyed.get()){
return;
}
// 移除出 `unsubscribed` 变量
super.unsubscribe(url, listener);
// 移除出 `failedSubscribed` `failedUnsubscribed` `failedNotified`
removeFailedSubscribed(url, listener);
// 向注册中心发送取消订阅请求
try {
// Sending a canceling subscription request to the server side
doUnsubscribe(url, listener);
} catch (Exception e) {
Throwable t = e;
// 如果开启了启动时检测，则直接抛出异常
// If the startup detection is opened, the Exception is thrown directly.
boolean check = getUrl().getParameter(Constants.CHECK_KEY, true)
&& url.getParameter(Constants.CHECK_KEY, true);
boolean skipFailback = t instanceof SkipFailbackWrapperException;
if (check || skipFailback) {
if (skipFailback) {
t = t.getCause();
}
throw new IllegalStateException("Failed to unsubscribe " + url + " to registry " + getUrl().getAddress() + ", cause: " + t.getMessage(), t);
} else {
logger.error("Failed to unsubscribe " + url + ", waiting for retry, cause: " + t.getMessage(), t);
}
// 将失败的订阅请求记录到 `failedUnsubscribed`，定时重试
// Record a failed registration request to a failed list, retry regularly
Set<NotifyListener> listeners = failedUnsubscribed.get(url);
if (listeners == null) {
failedUnsubscribed.putIfAbsent(url, new ConcurrentHashSet<NotifyListener>());
listeners = failedUnsubscribed.get(url);
}
listeners.add(listener);
}
}
@Override
protected void notify(URL url, NotifyListener listener, List<URL> urls) {
if (url == null) {
throw new IllegalArgumentException("notify url == null");
}
if (listener == null) {
throw new IllegalArgumentException("notify listener == null");
}
// 通知监听器
try {
doNotify(url, listener, urls);
} catch (Exception t) {
// 将失败的通知记录到 `failedNotified`，定时重试
Map<NotifyListener, List<URL>> listeners = failedNotified.get(url);
if (listeners == null) {
failedNotified.putIfAbsent(url, new ConcurrentHashMap<NotifyListener, List<URL>>());
listeners = failedNotified.get(url);
}
listeners.put(listener, urls);
logger.error("Failed to notify for subscribe " + url + ", waiting for retry, cause: " + t.getMessage(), t);
}
}
protected void doNotify(URL url, NotifyListener listener, List<URL> urls) {
super.notify(url, listener, urls);
}
@Override
protected void recover() throws Exception {
// register 恢复注册，添加到 `failedRegistered` ，定时重试
Set<URL> recoverRegistered = new HashSet<URL>(getRegistered());
if (!recoverRegistered.isEmpty()) {
if (logger.isInfoEnabled()) {
logger.info("Recover register url " + recoverRegistered);
}
for (URL url : recoverRegistered) {
failedRegistered.add(url);
}
}
// subscribe 恢复订阅，添加到 `failedSubscribed` ，定时重试
Map<URL, Set<NotifyListener>> recoverSubscribed = new HashMap<URL, Set<NotifyListener>>(getSubscribed());
if (!recoverSubscribed.isEmpty()) {
if (logger.isInfoEnabled()) {
logger.info("Recover subscribe url " + recoverSubscribed.keySet());
}
for (Map.Entry<URL, Set<NotifyListener>> entry : recoverSubscribed.entrySet()) {
URL url = entry.getKey();
for (NotifyListener listener : entry.getValue()) {
addFailedSubscribed(url, listener);
}
}
}
}
/**
* 重试
*/
protected void retry() {
// 重试执行注册
if (!failedRegistered.isEmpty()) {
Set<URL> failed = new HashSet<URL>(failedRegistered); // 避免并发冲突
if (failed.size() > 0) {
if (logger.isInfoEnabled()) {
logger.info("Retry register " + failed);
}
try {
for (URL url : failed) {
try {
// 执行注册
doRegister(url);
// 移除出 `failedRegistered`
failedRegistered.remove(url);
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry register " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry register " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
// 重试执行取消注册
if (!failedUnregistered.isEmpty()) {
Set<URL> failed = new HashSet<URL>(failedUnregistered); // 避免并发冲突
if (!failed.isEmpty()) {
if (logger.isInfoEnabled()) {
logger.info("Retry unregister " + failed);
}
try {
for (URL url : failed) {
try {
// 执行取消注册
doUnregister(url);
// 移除出 `failedUnregistered`
failedUnregistered.remove(url);
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry unregister " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry unregister " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
// 重试执行注册
if (!failedSubscribed.isEmpty()) {
Map<URL, Set<NotifyListener>> failed = new HashMap<URL, Set<NotifyListener>>(failedSubscribed); // 避免并发冲突
for (Map.Entry<URL, Set<NotifyListener>> entry : new HashMap<URL, Set<NotifyListener>>(failed).entrySet()) {
if (entry.getValue() == null || entry.getValue().size() == 0) {
failed.remove(entry.getKey());
}
}
if (failed.size() > 0) {
if (logger.isInfoEnabled()) {
logger.info("Retry subscribe " + failed);
}
try {
for (Map.Entry<URL, Set<NotifyListener>> entry : failed.entrySet()) {
URL url = entry.getKey();
Set<NotifyListener> listeners = entry.getValue();
for (NotifyListener listener : listeners) {
try {
// 执行注册
doSubscribe(url, listener);
// 移除出监听器
listeners.remove(listener);
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry subscribe " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry subscribe " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
// 重试执行取消注册
if (!failedUnsubscribed.isEmpty()) {
Map<URL, Set<NotifyListener>> failed = new HashMap<URL, Set<NotifyListener>>(failedUnsubscribed);
for (Map.Entry<URL, Set<NotifyListener>> entry : new HashMap<URL, Set<NotifyListener>>(failed).entrySet()) {
if (entry.getValue() == null || entry.getValue().isEmpty()) {
failed.remove(entry.getKey());
}
}
if (failed.size() > 0) {
if (logger.isInfoEnabled()) {
logger.info("Retry unsubscribe " + failed);
}
try {
for (Map.Entry<URL, Set<NotifyListener>> entry : failed.entrySet()) {
URL url = entry.getKey();
Set<NotifyListener> listeners = entry.getValue();
for (NotifyListener listener : listeners) {
try {
// 执行取消注册
doUnsubscribe(url, listener);
// 移除出监听器
listeners.remove(listener);
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry unsubscribe " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry unsubscribe " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
// 重试执行通知监听器
if (!failedNotified.isEmpty()) {
Map<URL, Map<NotifyListener, List<URL>>> failed = new HashMap<URL, Map<NotifyListener, List<URL>>>(failedNotified);
for (Map.Entry<URL, Map<NotifyListener, List<URL>>> entry : new HashMap<URL, Map<NotifyListener, List<URL>>>(failed).entrySet()) {
if (entry.getValue() == null || entry.getValue().size() == 0) {
failed.remove(entry.getKey());
}
}
if (failed.size() > 0) {
if (logger.isInfoEnabled()) {
logger.info("Retry notify " + failed);
}
try {
for (Map<NotifyListener, List<URL>> values : failed.values()) {
for (Map.Entry<NotifyListener, List<URL>> entry : values.entrySet()) {
try {
NotifyListener listener = entry.getKey();
List<URL> urls = entry.getValue();
// 通知监听器
listener.notify(urls);
// 移除出监听器
values.remove(listener);
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry notify " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
logger.warn("Failed to retry notify " + failed + ", waiting for again, cause: " + t.getMessage(), t);
}
}
}
}
@Override
public void destroy() {
// 忽略，若已经销毁
if (!canDestroy()) {
return;
}
// 调用父方法，取消注册和订阅
super.destroy();
// 销毁重试任务
try {
retryFuture.cancel(true);
} catch (Throwable t) {
logger.warn(t.getMessage(), t);
}
}
// TODO: 2017/8/30 to abstract this method
protected boolean canDestroy(){
return destroyed.compareAndSet(false, true);
}
// ==== Template method ====
protected abstract void doRegister(URL url);
protected abstract void doUnregister(URL url);
protected abstract void doSubscribe(URL url, NotifyListener listener);
protected abstract void doUnsubscribe(URL url, NotifyListener listener);
}
|
