Feign Retryer的預設重試策略測試
阿新 • • 發佈：2019-04-26
1、Feign配置
@Configuration public class FeignConfig { @Value("${coupon_service.url:http://localhost:8081}") private String couponServiceUrl; @Bean public CouponQueryServiceApi queryCouponServiceApi() { // connectTimeoutMillis=5*1000 連結超時時間 // readTimeoutMillis=10*1000 響應超時時間，如果超過10秒沒有接過發起下一次請求 Request.Options options = new Request.Options(5 * 1000, 10 * 1000); // period=100 發起當前請求的時間間隔，單位毫秒 // maxPeriod=1000 發起當前請求的最大時間間隔，單位毫秒 // maxAttempts=5 最多請求次數，包括第一次 Retryer neverRetry = new Retryer.Default(100, 1000, 5); return Feign.builder() .encoder(new JacksonEncoder()) .decoder(new JacksonDecoder()) .options(options) .retryer(neverRetry) .target(CouponQueryServiceApi.class, couponServiceUrl); } }
2、呼叫方用時 51273毫秒
3、服務方時間詳細記錄
| 次數 | 請求時間 | 響應時間 | 發起當前請求時間間隔 |
|---|---|---|---|
| 1 | 2019-04-26 11:18:03.042 | 2019-04-26 11:18:15.104 | 100*(1.5*0)=0 |
| 2 | 2019-04-26 11:18:13.202 | 2019-04-26 11:18:25.224 | 100*1.5*1=150 |
| 3 | 2019-04-26 11:18:23.436 | 2019-04-26 11:18:35.460 | 100*1.5*1.5=225 |
| 4 | 2019-04-26 11:18:33.781 | 2019-04-26 11:18:45.804 | 100*1.5*1.5*1.5=337 |
| 5 | 2019-04-26 11:18:44.292 | 2019-04-26 11:18:56.333 | 100*1.5*1.5*1.5*1.5=506 |
| 10秒中後超時 | 2019-04-26 11:18:54.292 |
| 本次請求開始時間 | 2019-04-26 11:18:03.042 |
| 本次請求結束時間 | 2019-04-26 11:18:54.292 |
| 總耗時 | 51.25 |
4、核心方法
/**
* feign.SynchronousMethodHandler#invoke
*/
@Override
public Object invoke(Object[] argv) throws Throwable {
RequestTemplate template = buildTemplateFromArgs.create(argv);
Retryer retryer = this.retryer.clone();
while (true) {
try {
return executeAndDecode(template);
} catch (RetryableException e) {
retryer.continueOrPropagate(e);
if (logLevel != Logger.Level.NONE) {
logger.logRetry(metadata.configKey(), logLevel);
}
continue;
}
}
}/**
* feign.SynchronousMethodHandler#executeAndDecode
*/
Object executeAndDecode(RequestTemplate template) throws Throwable {
Request request = targetRequest(template);
if (logLevel != Logger.Level.NONE) {
logger.logRequest(metadata.configKey(), logLevel, request);
}
Response response;
long start = System.nanoTime();
try {
response = client.execute(request, options);
// ensure the request is set. TODO: remove in Feign 10
response.toBuilder().request(request).build();
} catch (IOException e) {
if (logLevel != Logger.Level.NONE) {
logger.logIOException(metadata.configKey(), logLevel, e, elapsedTime(start));
}
throw errorExecuting(request, e);
}
long elapsedTime = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start);
boolean shouldClose = true;
try {
if (logLevel != Logger.Level.NONE) {
response =
logger.logAndRebufferResponse(metadata.configKey(), logLevel, response, elapsedTime);
// ensure the request is set. TODO: remove in Feign 10
response.toBuilder().request(request).build();
}
if (Response.class == metadata.returnType()) {
if (response.body() == null) {
return response;
}
if (response.body().length() == null ||
response.body().length() > MAX_RESPONSE_BUFFER_SIZE) {
shouldClose = false;
return response;
}
// Ensure the response body is disconnected
byte[] bodyData = Util.toByteArray(response.body().asInputStream());
return response.toBuilder().body(bodyData).build();
}
if (response.status() >= 200 && response.status() < 300) {
if (void.class == metadata.returnType()) {
return null;
} else {
return decode(response);
}
} else if (decode404 && response.status() == 404 && void.class != metadata.returnType()) {
return decode(response);
} else {
throw errorDecoder.decode(metadata.configKey(), response);
}
} catch (IOException e) {
if (logLevel != Logger.Level.NONE) {
logger.logIOException(metadata.configKey(), logLevel, e, elapsedTime);
}
throw errorReading(request, response, e);
} finally {
if (shouldClose) {
ensureClosed(response.body());
}
}
}/**
* feign.Retryer.Default#continueOrPropagate
*/
public void continueOrPropagate(RetryableException e) {
if (attempt++ >= maxAttempts) {
throw e;
}
long interval;
if (e.retryAfter() != null) {
interval = e.retryAfter().getTime() - currentTimeMillis();
if (interval > maxPeriod) {
interval = maxPeriod;
}
if (interval < 0) {
return;
}
} else {
interval = nextMaxInterval();
}
try {
Thread.sleep(interval);
} catch (InterruptedException ignored) {
Thread.currentThread().interrupt();
}
sleptForMillis += interval;
}
/*
* feign.Retryer.Default#nextMaxInterval
*/
long nextMaxInterval() {
long interval = (long) (period * Math.pow(1.5, attempt - 1));
return interval > maxPeriod ? maxPeriod : interval;
}