add docs and unit-test

Signed-off-by: jiangyuan <[email protected]>

Author: JoeCqupt

docs/modules/ROOT/pages/spring-cloud-gateway/gatewayfilter-factories/retry-factory.adoc

@@ -12,6 +12,9 @@ The `Retry` `GatewayFilter` factory supports the following parameters:
 Retries are performed after a backoff interval of `firstBackoff * (factor ^ n)`, where `n` is the iteration.
 If `maxBackoff` is configured, the maximum backoff applied is limited to `maxBackoff`.
 If `basedOnPreviousValue` is true, the backoff is calculated by using `prevBackoff * factor`.
+* `jitter`: The configured random jitter for the retries.
+Generating a backoff between `[backoff - backoff*randomFactor, backoff + backoff*randomFactor]`
+* `timeout`:  The configured timeout for the retries.
 
 The following defaults are configured for `Retry` filter, if enabled:
 
@@ -20,6 +23,8 @@ The following defaults are configured for `Retry` filter, if enabled:
 * `methods`: GET method
 * `exceptions`: `IOException` and `TimeoutException`
 * `backoff`: disabled
+* `jitter`: disabled
+* `timeout`: unlimited
 
 The following listing configures a Retry `GatewayFilter`:
 
@@ -45,6 +50,9 @@ spring:
               maxBackoff: 50ms
               factor: 2
               basedOnPreviousValue: false
+            jitter:
+              randomFactor: 0.5
+            timeout: 100ms
 ----
 
 NOTE: When using the retry filter with a `forward:` prefixed URL, the target endpoint should be written carefully so that, in case of an error, it does not do anything that could result in a response being sent to the client and committed.
@@ -77,10 +85,13 @@ spring:
               maxBackoff: 50ms
               factor: 2
               basedOnPreviousValue: false
+            jitter:
+              randomFactor: 0.5
+            timeout: 100ms
 
       - id: retryshortcut_route
         uri: https://example.org
         filters:
-        - Retry=3,INTERNAL_SERVER_ERROR,GET,10ms,50ms,2,false
+        - Retry=3,INTERNAL_SERVER_ERROR,GET,10ms,50ms,2,false,0.5,100ms
 ----
 

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/factory/RetryGatewayFilterFactory.java

@@ -492,7 +492,8 @@ public static class JitterConfig {
 		private double randomFactor = 0.5;
 
 		public void validate() {
-			Assert.isTrue(randomFactor >= 0 && randomFactor <= 1, "random factor must be between 0 and 1 (default 0.5)");
+			Assert.isTrue(randomFactor >= 0 && randomFactor <= 1,
+					"random factor must be between 0 and 1 (default 0.5)");
 		}
 
 		public JitterConfig() {
@@ -509,6 +510,7 @@ public double getRandomFactor() {
 		public void setRandomFactor(double randomFactor) {
 			this.randomFactor = randomFactor;
 		}
+
 	}
 
 }

spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/filter/factory/RetryGatewayFilterFactoryIntegrationTests.java

@@ -109,6 +109,18 @@ public void retryWithBackoff() {
 		// @formatter:on
 	}
 
+	@Test
+	public void retryWithBackoffJitterTimeout() {
+		// @formatter:off
+		testClient.get()
+				.uri("/retry?key=retry-with-backoff-jitter-timeout&count=3")
+				.header(HttpHeaders.HOST, "www.retrywithbackoffjittertimeout.org")
+				.exchange()
+				.expectStatus().isOk()
+				.expectHeader().value("X-Retry-Count", CoreMatchers.equalTo("3"));
+		// @formatter:on
+	}
+
 	@Test
 	public void retryFilterGetJavaDsl() {
 		testClient.get()

spring-cloud-gateway-server/src/test/resources/application-retrytests.yml

@@ -29,3 +29,22 @@ spring:
             - name: Retry
               args:
                 methods: GET,POST
+        # =====================================
+        - id: retry_with_backoff_jitter_timeout_test
+          uri: ${test.uri}
+          predicates:
+            - Host=**.retrywithbackoffjittertimeout.org
+          filters:
+            - name: Retry
+              args:
+                retries: 3
+                statuses: INTERNAL_SERVER_ERROR
+                methods: GET
+                backoff:
+                  firstBackoff: 10ms
+                  maxBackoff: 50ms
+                  factor: 2
+                  basedOnPreviousValue: false
+                jitter:
+                  randomFactor: 0.5
+                timeout: 200ms