feat: Support new 2026 retries

gems/aws-sdk-core/CHANGELOG.md

@@ -1,7 +1,9 @@
 Unreleased Changes
 ------------------
+
 * Feature - Add YJIT & ZJIT tracking to user agent.
 * Issue - Fix error messaging in SSO OIDC.
+* Feature - Add `AWS_NEW_RETRIES_2026` environment variable to opt-in to updated `standard` retry mode with reduced backoff intervals.
 
 3.246.0 (2026-04-23)
 ------------------

gems/aws-sdk-core/lib/aws-sdk-core/plugins/retries/retry_quota.rb

@@ -8,9 +8,11 @@ module Retries
       # Used in 'standard' and 'adaptive' retry modes.
       class RetryQuota
         INITIAL_RETRY_TOKENS = 500
-        RETRY_COST = 5
+        RETRY_COST = 14
+        LEGACY_RETRY_COST = 5 # TODO: Remove when new retries become default
         NO_RETRY_INCREMENT = 1
-        TIMEOUT_RETRY_COST = 10
+        THROTTLING_RETRY_COST = 5
+        TIMEOUT_RETRY_COST = 10 # TODO: Remove when new retries become default
 
         def initialize(opts = {})
           @mutex              = Mutex.new
@@ -19,15 +21,16 @@ def initialize(opts = {})
         end
 
         # check if there is sufficient capacity to retry
-        # and return it.  If there is insufficient capacity
+        # and return it. If there is insufficient capacity
         # return 0
         # @return [Integer] The amount of capacity checked out
         def checkout_capacity(error_inspector)
           @mutex.synchronize do
-            capacity_amount = if error_inspector.networking?
-                                TIMEOUT_RETRY_COST
+            # TODO: Remove gate and keep only the new_retries branch
+            capacity_amount = if RetryErrors.new_retries?
+                                error_inspector.throttling_error? ? THROTTLING_RETRY_COST : RETRY_COST
                               else
-                                RETRY_COST
+                                error_inspector.networking? ? TIMEOUT_RETRY_COST : LEGACY_RETRY_COST
                               end
 
             # unable to acquire capacity
@@ -39,8 +42,8 @@ def checkout_capacity(error_inspector)
         end
 
         # capacity_amount refers to the amount of capacity requested from
-        # the last retry.  It can either be RETRY_COST, TIMEOUT_RETRY_COST,
-        # or unset.
+        # the last retry. It can either be RETRY_COST,
+        # THROTTLING_RETRY_COST/TIMEOUT_RETRY_COST, or unset.
         def release(capacity_amount)
           # Implementation note:  The release() method is called for
           # every API call.  In the common case where the request is