core: fix the backoff range to [0.8, 1.2] as per the A6 redefinition (#12639)

wcchoi · web-flow · commit 024fdd0ead5a · 2026-02-09T17:25:12.000+05:30
The range is [0.4, 1.2] in code [spec](https://github.com/grpc/proposal/blob/6a8163b49157f2e19a5a7535a5957398d99701f1/A6-client-retries.md?plain=1#L113) mentions [0.8, 1.2].
diff --git a/core/src/main/java/io/grpc/internal/RetriableStream.java b/core/src/main/java/io/grpc/internal/RetriableStream.java
@@ -853,7 +853,7 @@ public void run() {
 
   public static long intervalWithJitter(long intervalNanos) {
     double inverseJitterFactor = isExperimentalRetryJitterEnabled
-            ? 0.8 * random.nextDouble() + 0.4 : random.nextDouble();
+            ? 0.4 * random.nextDouble() + 0.8 : random.nextDouble();
     return (long) (intervalNanos * inverseJitterFactor);
   }
 

Original file line number	Diff line number	Diff line change
`@@ -853,7 +853,7 @@ public void run() {`
`853`	`853`
`854`	`854`	`public static long intervalWithJitter(long intervalNanos) {`
`855`	`855`	`double inverseJitterFactor = isExperimentalRetryJitterEnabled`
`856`		`- ? 0.8 * random.nextDouble() + 0.4 : random.nextDouble();`
	`856`	`+ ? 0.4 * random.nextDouble() + 0.8 : random.nextDouble();`
`857`	`857`	`return (long) (intervalNanos * inverseJitterFactor);`
`858`	`858`	`}`
`859`	`859`