From ec917ed6d0b93522fed93175333f5c826883ebc7 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Fri, 11 Jul 2025 12:55:02 -0700
Subject: [PATCH 01/10] Thread local approach

---
 .../lib/smithy-client/pageable_response.rb         | 10 +++++++++-
 .../lib/smithy-client/plugins/protocol.rb          | 13 ++++++++++++-
 .../smithy-client/plugins/request_compression.rb   | 13 ++++++++++++-
 .../lib/smithy-client/plugins/retry_errors.rb      | 14 ++++++++++++++
 .../lib/smithy-client/waiters/poller.rb            | 10 +++++++++-
 5 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/pageable_response.rb b/gems/smithy-client/lib/smithy-client/pageable_response.rb
index 99b5e8844..f3f16b4dc 100644
--- a/gems/smithy-client/lib/smithy-client/pageable_response.rb
+++ b/gems/smithy-client/lib/smithy-client/pageable_response.rb
@@ -92,7 +92,7 @@ def next_page(params = {})
         raise LastPageError, self if last_page?
 
         params = next_page_params(params)
-        context.client.send(context.operation_name, params)
+        with_metric { context.client.send(context.operation_name, params) }
       end
 
       # Yields the current and each following response to the given block.
@@ -133,6 +133,14 @@ def next_page_params(params)
         new_params = context.params.except(*prev_tokens)
         new_params.merge!(@paginator.next_tokens(data).merge(params))
       end
+
+      def with_metric(&block)
+        Thread.current[:aws_sdk_core_user_agent_metric] ||= []
+        Thread.current[:aws_sdk_core_user_agent_metric] << 'C'
+        block.call
+      ensure
+        Thread.current[:aws_sdk_core_user_agent_metric].pop
+      end
     end
   end
 end
diff --git a/gems/smithy-client/lib/smithy-client/plugins/protocol.rb b/gems/smithy-client/lib/smithy-client/plugins/protocol.rb
index 4451434a7..7ca694277 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/protocol.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/protocol.rb
@@ -16,7 +16,18 @@ class Protocol < Plugin
         class BuildHandler < Handler
           def call(context)
             context.config.protocol.build_request(context)
-            @handler.call(context)
+            with_metric(context.config.protocol) { @handler.call(context) }
+          end
+
+          def with_metric(protocol, &block)
+            metric = protocol.is_a?(Smithy::Client::RPCv2CBOR::Protocol) ? 'M' : nil
+            return block.call unless metric
+
+            Thread.current[:smithy_ruby_user_agent_metric] ||= []
+            Thread.current[:smithy_ruby_user_agent_metric] << metric
+            block.call
+          ensure
+            Thread.current[:smithy_ruby_user_agent_metric].pop
           end
         end
 
diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index a9c5653d0..64bf8e3ac 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -77,7 +77,7 @@ def call(context)
                 end
               end
             end
-            @handler.call(context)
+            with_metric(selected_encoding) { @handler.call(context) }
           end
 
           private
@@ -149,6 +149,17 @@ def update_content_encoding(encoding, context)
             end
           end
 
+          def with_metric(encoding, &block)
+            metric = encoding == 'gzip' ? 'L' : nil
+            return block.call unless metric
+
+            Thread.current[:smithy_ruby_user_agent_metric] ||= []
+            Thread.current[:smithy_ruby_user_agent_metric] << metric
+            block.call
+          ensure
+            Thread.current[:smithy_ruby_user_agent_metric].pop
+          end
+
           # @api private
           class GzipIO
             def initialize(body)
diff --git a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
index 915af5865..27042c967 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
@@ -117,6 +117,20 @@ def reset_response(context, response)
             context.http_response.reset
             response.error = nil
           end
+
+          def with_metric(retry_strategy, &block)
+            metric = case retry_strategy
+                     when Retry::Standard then 'E'
+                     when Retry::Adaptive then 'F'
+                     else return block.call
+                     end
+
+            Thread.current[:smithy_ruby_user_agent_metric] ||= []
+            Thread.current[:smithy_ruby_user_agent_metric] << metric
+            block.call
+          ensure
+            Thread.current[:smithy_ruby_user_agent_metric].pop if metric
+          end
         end
 
         handler(Handler, step: :retry)
diff --git a/gems/smithy-client/lib/smithy-client/waiters/poller.rb b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
index 3fdd25649..89293da0c 100644
--- a/gems/smithy-client/lib/smithy-client/waiters/poller.rb
+++ b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
@@ -15,7 +15,7 @@ def call(client, params)
           @input = params
           request = client.build_request(@operation_name, params)
           request.handlers.remove(Plugins::RaiseResponseErrors::Handler)
-          response = request.send_request
+          response = with_metric { request.send_request }
           status = evaluate_acceptors(response)
           [response, status.to_sym]
         end
@@ -87,6 +87,14 @@ def anyStringEquals?(actual, expected)
           actual.any? { |value| value == expected }
         end
         # rubocop:enable Naming/MethodName
+
+        def with_metric (&block)
+          Thread.current[:smithy_ruby_user_agent_metric] ||= []
+          Thread.current[:smithy_ruby_user_agent_metric] << 'B'
+          block.call
+        ensure
+          Thread.current[:smithy_ruby_user_agent_metric].pop
+        end
       end
     end
   end

From ba083b431a18d5488361bf6b8b30518633998418 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Mon, 14 Jul 2025 11:13:27 -0700
Subject: [PATCH 02/10] Context approach

---
 .../lib/smithy-client/pageable_response.rb             |  6 +++++-
 .../lib/smithy-client/plugins/request_compression.rb   | 10 +++++++++-
 .../lib/smithy-client/plugins/retry_errors.rb          | 10 ++++++++++
 .../lib/smithy-client/rpc_v2_cbor/handler.rb           |  3 +++
 gems/smithy-client/lib/smithy-client/waiters/poller.rb |  9 ++++++++-
 5 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/pageable_response.rb b/gems/smithy-client/lib/smithy-client/pageable_response.rb
index f3f16b4dc..7b797f339 100644
--- a/gems/smithy-client/lib/smithy-client/pageable_response.rb
+++ b/gems/smithy-client/lib/smithy-client/pageable_response.rb
@@ -92,7 +92,11 @@ def next_page(params = {})
         raise LastPageError, self if last_page?
 
         params = next_page_params(params)
-        with_metric { context.client.send(context.operation_name, params) }
+        context[:user_agent_feature_ids] ||= []
+        context[:user_agent_feature_ids] << 'PAGINATOR'
+        resp = context.client.send(context.operation_name, params)
+        context[:user_agent_feature_ids].delete('PAGINATOR')
+        resp
       end
 
       # Yields the current and each following response to the given block.
diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index 64bf8e3ac..1d12b81e6 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -77,7 +77,15 @@ def call(context)
                 end
               end
             end
-            with_metric(selected_encoding) { @handler.call(context) }
+            if selected_encoding == 'gzip'
+              context[:user_agent_feature_ids] ||= []
+              context[:user_agent_feature_ids] << 'GZIP_REQUEST_COMPRESSION'
+              response = @handler.call(context)
+              context[:user_agent_feature_ids].delete('GZIP_REQUEST_COMPRESSION')
+              response
+            else
+              @handler.call(context)
+            end
           end
 
           private
diff --git a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
index 27042c967..96525bc98 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
@@ -84,7 +84,17 @@ def call(context)
           private
 
           def handle(context, retry_strategy, token)
+            feature_id = case retry_strategy
+                         when Retry::Standard then 'RETRY_MODE_STANDARD'
+                         when Retry::Adaptive then 'RETRY_MODE_ADAPTIVE'
+                         end
+            if feature_id
+              context[:user_agent_feature_ids] ||= []
+              context[:user_agent_feature_ids] << feature_id
+            end
             response = @handler.call(context)
+            context[:user_agent_feature_ids]&.delete(feature_id) if feature_id
+
             if (error = response.error)
               return response unless retryable?(context.http_request)
 
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
index 45abb038a..3036c23d9 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
@@ -6,8 +6,11 @@ module RpcV2Cbor
       # @api private
       class Handler < Client::Handler
         def call(context)
+          context[:user_agent_feature_ids] ||= []
+          context[:user_agent_feature_ids] << 'PROTOCOL_RPC_V2_CBOR'
           build_request(context)
           response = @handler.call(context)
+          context[:user_agent_feature_ids].delete('PROTOCOL_RPC_V2_CBOR')
           response.on_done(200..299) { |resp| resp.data = parse_body(context) }
           response
         end
diff --git a/gems/smithy-client/lib/smithy-client/waiters/poller.rb b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
index 89293da0c..bc8fc3b87 100644
--- a/gems/smithy-client/lib/smithy-client/waiters/poller.rb
+++ b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
@@ -15,7 +15,14 @@ def call(client, params)
           @input = params
           request = client.build_request(@operation_name, params)
           request.handlers.remove(Plugins::RaiseResponseErrors::Handler)
-          response = with_metric { request.send_request }
+          request.handle do |context|
+            context[:user_agent_feature_ids] ||= []
+            context[:user_agent_feature_ids] << 'WAITER'
+            @handler.call(context)
+          ensure
+            context.config[:user_agent_feature_ids].delete('WAITER')
+          end
+          response = request.send_request
           status = evaluate_acceptors(response)
           [response, status.to_sym]
         end

From 674da7cfd982cc75802bf5e21feb1f4ef607b9f7 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Tue, 15 Jul 2025 10:52:49 -0700
Subject: [PATCH 03/10] Features module

---
 gems/smithy-client/lib/smithy-client.rb       |  1 +
 .../lib/smithy-client/features.rb             | 20 +++++++++++++
 .../lib/smithy-client/pageable_response.rb    | 14 +---------
 .../plugins/request_compression.rb            | 23 ++++-----------
 .../lib/smithy-client/plugins/retry_errors.rb | 28 ++++---------------
 .../lib/smithy-client/rpc_v2_cbor/handler.rb  |  5 +---
 .../lib/smithy-client/waiters/poller.rb       | 17 +----------
 7 files changed, 36 insertions(+), 72 deletions(-)
 create mode 100644 gems/smithy-client/lib/smithy-client/features.rb

diff --git a/gems/smithy-client/lib/smithy-client.rb b/gems/smithy-client/lib/smithy-client.rb
index c85cea37b..c3b8be960 100644
--- a/gems/smithy-client/lib/smithy-client.rb
+++ b/gems/smithy-client/lib/smithy-client.rb
@@ -14,6 +14,7 @@
 require_relative 'smithy-client/default_params'
 require_relative 'smithy-client/dynamic_errors'
 require_relative 'smithy-client/endpoint_rules'
+require_relative 'smithy-client/features'
 require_relative 'smithy-client/handler'
 require_relative 'smithy-client/handler_builder'
 require_relative 'smithy-client/handler_context'
diff --git a/gems/smithy-client/lib/smithy-client/features.rb b/gems/smithy-client/lib/smithy-client/features.rb
new file mode 100644
index 000000000..6741baff3
--- /dev/null
+++ b/gems/smithy-client/lib/smithy-client/features.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Smithy
+  module Client
+    # @api private
+    module Features
+      def self.clear
+        Thread.current[:smithy_ruby_user_agent_metric] = []
+      end
+
+      def self.with_metric(*metrics, &block)
+        Thread.current[:smithy_ruby_user_agent_metric] ||= []
+        Thread.current[:smithy_ruby_user_agent_metric].concat(metrics)
+        block.call
+      ensure
+        Thread.current[:smithy_ruby_user_agent_metric].pop(metrics.size)
+      end
+    end
+  end
+end
diff --git a/gems/smithy-client/lib/smithy-client/pageable_response.rb b/gems/smithy-client/lib/smithy-client/pageable_response.rb
index 7b797f339..6e97d87b7 100644
--- a/gems/smithy-client/lib/smithy-client/pageable_response.rb
+++ b/gems/smithy-client/lib/smithy-client/pageable_response.rb
@@ -92,11 +92,7 @@ def next_page(params = {})
         raise LastPageError, self if last_page?
 
         params = next_page_params(params)
-        context[:user_agent_feature_ids] ||= []
-        context[:user_agent_feature_ids] << 'PAGINATOR'
-        resp = context.client.send(context.operation_name, params)
-        context[:user_agent_feature_ids].delete('PAGINATOR')
-        resp
+        Features.with_metric('PAGINATOR') { context.client.send(context.operation_name, params) }
       end
 
       # Yields the current and each following response to the given block.
@@ -137,14 +133,6 @@ def next_page_params(params)
         new_params = context.params.except(*prev_tokens)
         new_params.merge!(@paginator.next_tokens(data).merge(params))
       end
-
-      def with_metric(&block)
-        Thread.current[:aws_sdk_core_user_agent_metric] ||= []
-        Thread.current[:aws_sdk_core_user_agent_metric] << 'C'
-        block.call
-      ensure
-        Thread.current[:aws_sdk_core_user_agent_metric].pop
-      end
     end
   end
 end
diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index 1d12b81e6..72bd8c231 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -77,15 +77,7 @@ def call(context)
                 end
               end
             end
-            if selected_encoding == 'gzip'
-              context[:user_agent_feature_ids] ||= []
-              context[:user_agent_feature_ids] << 'GZIP_REQUEST_COMPRESSION'
-              response = @handler.call(context)
-              context[:user_agent_feature_ids].delete('GZIP_REQUEST_COMPRESSION')
-              response
-            else
-              @handler.call(context)
-            end
+            with_metric(selected_encoding) { @handler.call(context) }
           end
 
           private
@@ -158,14 +150,11 @@ def update_content_encoding(encoding, context)
           end
 
           def with_metric(encoding, &block)
-            metric = encoding == 'gzip' ? 'L' : nil
-            return block.call unless metric
-
-            Thread.current[:smithy_ruby_user_agent_metric] ||= []
-            Thread.current[:smithy_ruby_user_agent_metric] << metric
-            block.call
-          ensure
-            Thread.current[:smithy_ruby_user_agent_metric].pop
+            if encoding == 'gzip'
+              Features.with_metric('GZIP_REQUEST_COMPRESSION', &block)
+            else
+              block.call
+            end
           end
 
           # @api private
diff --git a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
index 96525bc98..4e47f6168 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
@@ -84,17 +84,7 @@ def call(context)
           private
 
           def handle(context, retry_strategy, token)
-            feature_id = case retry_strategy
-                         when Retry::Standard then 'RETRY_MODE_STANDARD'
-                         when Retry::Adaptive then 'RETRY_MODE_ADAPTIVE'
-                         end
-            if feature_id
-              context[:user_agent_feature_ids] ||= []
-              context[:user_agent_feature_ids] << feature_id
-            end
-            response = @handler.call(context)
-            context[:user_agent_feature_ids]&.delete(feature_id) if feature_id
-
+            response = with_metric(retry_strategy) { @handler.call(context) }
             if (error = response.error)
               return response unless retryable?(context.http_request)
 
@@ -129,17 +119,11 @@ def reset_response(context, response)
           end
 
           def with_metric(retry_strategy, &block)
-            metric = case retry_strategy
-                     when Retry::Standard then 'E'
-                     when Retry::Adaptive then 'F'
-                     else return block.call
-                     end
-
-            Thread.current[:smithy_ruby_user_agent_metric] ||= []
-            Thread.current[:smithy_ruby_user_agent_metric] << metric
-            block.call
-          ensure
-            Thread.current[:smithy_ruby_user_agent_metric].pop if metric
+            case retry_strategy
+            when Retry::Standard then Features.with_metric('RETRY_MODE_STANDARD') { block.call }
+            when Retry::Adaptive then Features.with_metric('RETRY_MODE_ADAPTIVE') { block.call }
+            else block.call
+            end
           end
         end
 
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
index 3036c23d9..04eafca3e 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
@@ -6,11 +6,8 @@ module RpcV2Cbor
       # @api private
       class Handler < Client::Handler
         def call(context)
-          context[:user_agent_feature_ids] ||= []
-          context[:user_agent_feature_ids] << 'PROTOCOL_RPC_V2_CBOR'
           build_request(context)
-          response = @handler.call(context)
-          context[:user_agent_feature_ids].delete('PROTOCOL_RPC_V2_CBOR')
+          response = Features.with_metric('PROTOCOL_RPC_V2_CBOR') { @handler.call(context) }
           response.on_done(200..299) { |resp| resp.data = parse_body(context) }
           response
         end
diff --git a/gems/smithy-client/lib/smithy-client/waiters/poller.rb b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
index bc8fc3b87..bc0a6a549 100644
--- a/gems/smithy-client/lib/smithy-client/waiters/poller.rb
+++ b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
@@ -15,14 +15,7 @@ def call(client, params)
           @input = params
           request = client.build_request(@operation_name, params)
           request.handlers.remove(Plugins::RaiseResponseErrors::Handler)
-          request.handle do |context|
-            context[:user_agent_feature_ids] ||= []
-            context[:user_agent_feature_ids] << 'WAITER'
-            @handler.call(context)
-          ensure
-            context.config[:user_agent_feature_ids].delete('WAITER')
-          end
-          response = request.send_request
+          response = Features.with_metric('WAITER') { request.send_request }
           status = evaluate_acceptors(response)
           [response, status.to_sym]
         end
@@ -94,14 +87,6 @@ def anyStringEquals?(actual, expected)
           actual.any? { |value| value == expected }
         end
         # rubocop:enable Naming/MethodName
-
-        def with_metric (&block)
-          Thread.current[:smithy_ruby_user_agent_metric] ||= []
-          Thread.current[:smithy_ruby_user_agent_metric] << 'B'
-          block.call
-        ensure
-          Thread.current[:smithy_ruby_user_agent_metric].pop
-        end
       end
     end
   end

From 413935616dd07a68a51b6538c0c569b318136f28 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Tue, 15 Jul 2025 11:32:00 -0700
Subject: [PATCH 04/10] Clear thread in build request

---
 gems/smithy-client/lib/smithy-client/base.rb       | 1 +
 gems/smithy-client/lib/smithy-client/features.rb   | 1 -
 gems/smithy/lib/smithy/templates/client/client.erb | 1 +
 projections/shapes/lib/shapes/client.rb            | 1 +
 projections/weather/lib/weather/client.rb          | 1 +
 5 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/gems/smithy-client/lib/smithy-client/base.rb b/gems/smithy-client/lib/smithy-client/base.rb
index 460011c48..0c2ae30ef 100644
--- a/gems/smithy-client/lib/smithy-client/base.rb
+++ b/gems/smithy-client/lib/smithy-client/base.rb
@@ -22,6 +22,7 @@ def initialize(plugins, options)
       # @param [Symbol] operation_name
       # @return [Request]
       def build_request(operation_name, params = {})
+        Features.clear
         Request.new(
           handlers: @handlers.for(operation_name),
           context: context_for(operation_name, params)
diff --git a/gems/smithy-client/lib/smithy-client/features.rb b/gems/smithy-client/lib/smithy-client/features.rb
index 6741baff3..f5b6635e0 100644
--- a/gems/smithy-client/lib/smithy-client/features.rb
+++ b/gems/smithy-client/lib/smithy-client/features.rb
@@ -9,7 +9,6 @@ def self.clear
       end
 
       def self.with_metric(*metrics, &block)
-        Thread.current[:smithy_ruby_user_agent_metric] ||= []
         Thread.current[:smithy_ruby_user_agent_metric].concat(metrics)
         block.call
       ensure
diff --git a/gems/smithy/lib/smithy/templates/client/client.erb b/gems/smithy/lib/smithy/templates/client/client.erb
index edfde738e..b338af5c6 100644
--- a/gems/smithy/lib/smithy/templates/client/client.erb
+++ b/gems/smithy/lib/smithy/templates/client/client.erb
@@ -103,6 +103,7 @@ module <%= module_name %>
 
     # @api private
     def build_request(operation_name, params)
+      Smithy::Client::Features.clear
       handlers = @handlers.for(operation_name)
       context = Smithy::Client::HandlerContext.new(
         operation_name: operation_name,
diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 6d4a334c0..3f790e0cd 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -330,6 +330,7 @@ def wait_until(waiter_name, params = {}, options = {})
 
     # @api private
     def build_request(operation_name, params)
+      Smithy::Client::Features.clear
       handlers = @handlers.for(operation_name)
       context = Smithy::Client::HandlerContext.new(
         operation_name: operation_name,
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 5f6531af5..886aad51e 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -318,6 +318,7 @@ def wait_until(waiter_name, params = {}, options = {})
 
     # @api private
     def build_request(operation_name, params)
+      Smithy::Client::Features.clear
       handlers = @handlers.for(operation_name)
       context = Smithy::Client::HandlerContext.new(
         operation_name: operation_name,

From e79a5599b4e59960092eccfb5d6be6d52ed781c6 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Tue, 15 Jul 2025 11:50:33 -0700
Subject: [PATCH 05/10] Move clear

---
 gems/smithy-client/lib/smithy-client/base.rb       | 1 -
 gems/smithy-client/lib/smithy-client/request.rb    | 1 +
 gems/smithy/lib/smithy/templates/client/client.erb | 1 -
 projections/shapes/lib/shapes/client.rb            | 1 -
 projections/weather/lib/weather/client.rb          | 1 -
 5 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/base.rb b/gems/smithy-client/lib/smithy-client/base.rb
index 0c2ae30ef..460011c48 100644
--- a/gems/smithy-client/lib/smithy-client/base.rb
+++ b/gems/smithy-client/lib/smithy-client/base.rb
@@ -22,7 +22,6 @@ def initialize(plugins, options)
       # @param [Symbol] operation_name
       # @return [Request]
       def build_request(operation_name, params = {})
-        Features.clear
         Request.new(
           handlers: @handlers.for(operation_name),
           context: context_for(operation_name, params)
diff --git a/gems/smithy-client/lib/smithy-client/request.rb b/gems/smithy-client/lib/smithy-client/request.rb
index 3c7d12045..5d96c0bff 100644
--- a/gems/smithy-client/lib/smithy-client/request.rb
+++ b/gems/smithy-client/lib/smithy-client/request.rb
@@ -9,6 +9,7 @@ class Request
       # @option options [HandlerList] :handlers (nil)
       # @option options [HandlerContext] :context (nil)
       def initialize(options = {})
+        Features.clear
         @handlers = options[:handlers] || HandlerList.new
         @context = options[:context] || HandlerContext.new
       end
diff --git a/gems/smithy/lib/smithy/templates/client/client.erb b/gems/smithy/lib/smithy/templates/client/client.erb
index b338af5c6..edfde738e 100644
--- a/gems/smithy/lib/smithy/templates/client/client.erb
+++ b/gems/smithy/lib/smithy/templates/client/client.erb
@@ -103,7 +103,6 @@ module <%= module_name %>
 
     # @api private
     def build_request(operation_name, params)
-      Smithy::Client::Features.clear
       handlers = @handlers.for(operation_name)
       context = Smithy::Client::HandlerContext.new(
         operation_name: operation_name,
diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 3f790e0cd..6d4a334c0 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -330,7 +330,6 @@ def wait_until(waiter_name, params = {}, options = {})
 
     # @api private
     def build_request(operation_name, params)
-      Smithy::Client::Features.clear
       handlers = @handlers.for(operation_name)
       context = Smithy::Client::HandlerContext.new(
         operation_name: operation_name,
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 886aad51e..5f6531af5 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -318,7 +318,6 @@ def wait_until(waiter_name, params = {}, options = {})
 
     # @api private
     def build_request(operation_name, params)
-      Smithy::Client::Features.clear
       handlers = @handlers.for(operation_name)
       context = Smithy::Client::HandlerContext.new(
         operation_name: operation_name,

From d39dea8ce92b7b95cedb21af16065cde4c328a84 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Tue, 15 Jul 2025 15:08:47 -0700
Subject: [PATCH 06/10] Clean up and add tests

---
 .../lib/smithy-client/features.rb             | 12 ++-
 .../lib/smithy-client/pageable_response.rb    |  2 +-
 .../plugins/request_compression.rb            |  2 +-
 .../lib/smithy-client/plugins/retry_errors.rb |  4 +-
 .../lib/smithy-client/rpc_v2_cbor/handler.rb  |  2 +-
 .../lib/smithy-client/waiters/poller.rb       |  2 +-
 .../spec/smithy-client/features_spec.rb       | 81 +++++++++++++++++++
 7 files changed, 95 insertions(+), 10 deletions(-)
 create mode 100644 gems/smithy-client/spec/smithy-client/features_spec.rb

diff --git a/gems/smithy-client/lib/smithy-client/features.rb b/gems/smithy-client/lib/smithy-client/features.rb
index f5b6635e0..7cccd4fd5 100644
--- a/gems/smithy-client/lib/smithy-client/features.rb
+++ b/gems/smithy-client/lib/smithy-client/features.rb
@@ -5,14 +5,18 @@ module Client
     # @api private
     module Features
       def self.clear
-        Thread.current[:smithy_ruby_user_agent_metric] = []
+        Thread.current[:smithy_ruby_features] = []
       end
 
-      def self.with_metric(*metrics, &block)
-        Thread.current[:smithy_ruby_user_agent_metric].concat(metrics)
+      def self.track(*metrics, &block)
+        Thread.current[:smithy_ruby_features].concat(metrics)
         block.call
       ensure
-        Thread.current[:smithy_ruby_user_agent_metric].pop(metrics.size)
+        Thread.current[:smithy_ruby_features].pop(metrics.size)
+      end
+
+      def self.list
+        Thread.current[:smithy_ruby_features] || []
       end
     end
   end
diff --git a/gems/smithy-client/lib/smithy-client/pageable_response.rb b/gems/smithy-client/lib/smithy-client/pageable_response.rb
index 6e97d87b7..2f9fa1046 100644
--- a/gems/smithy-client/lib/smithy-client/pageable_response.rb
+++ b/gems/smithy-client/lib/smithy-client/pageable_response.rb
@@ -92,7 +92,7 @@ def next_page(params = {})
         raise LastPageError, self if last_page?
 
         params = next_page_params(params)
-        Features.with_metric('PAGINATOR') { context.client.send(context.operation_name, params) }
+        Features.track('PAGINATOR') { context.client.send(context.operation_name, params) }
       end
 
       # Yields the current and each following response to the given block.
diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index 72bd8c231..eb936b22b 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -151,7 +151,7 @@ def update_content_encoding(encoding, context)
 
           def with_metric(encoding, &block)
             if encoding == 'gzip'
-              Features.with_metric('GZIP_REQUEST_COMPRESSION', &block)
+              Features.track('GZIP_REQUEST_COMPRESSION', &block)
             else
               block.call
             end
diff --git a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
index 4e47f6168..481fa2dba 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
@@ -120,8 +120,8 @@ def reset_response(context, response)
 
           def with_metric(retry_strategy, &block)
             case retry_strategy
-            when Retry::Standard then Features.with_metric('RETRY_MODE_STANDARD') { block.call }
-            when Retry::Adaptive then Features.with_metric('RETRY_MODE_ADAPTIVE') { block.call }
+            when Retry::Standard then Features.track('RETRY_MODE_STANDARD') { block.call }
+            when Retry::Adaptive then Features.track('RETRY_MODE_ADAPTIVE') { block.call }
             else block.call
             end
           end
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
index 4822b26d5..98fd362ff 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
@@ -7,7 +7,7 @@ module RpcV2Cbor
       class Handler < Client::Handler
         def call(context)
           build_request(context)
-          response = Features.with_metric('PROTOCOL_RPC_V2_CBOR') { @handler.call(context) }
+          response = Features.track('PROTOCOL_RPC_V2_CBOR') { @handler.call(context) }
           response.on_done(200..299) { |resp| resp.data = parse_body(context) }
           response
         end
diff --git a/gems/smithy-client/lib/smithy-client/waiters/poller.rb b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
index bc0a6a549..74e2b7583 100644
--- a/gems/smithy-client/lib/smithy-client/waiters/poller.rb
+++ b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
@@ -15,7 +15,7 @@ def call(client, params)
           @input = params
           request = client.build_request(@operation_name, params)
           request.handlers.remove(Plugins::RaiseResponseErrors::Handler)
-          response = Features.with_metric('WAITER') { request.send_request }
+          response = Features.track('WAITER') { request.send_request }
           status = evaluate_acceptors(response)
           [response, status.to_sym]
         end
diff --git a/gems/smithy-client/spec/smithy-client/features_spec.rb b/gems/smithy-client/spec/smithy-client/features_spec.rb
new file mode 100644
index 000000000..8ed43a53e
--- /dev/null
+++ b/gems/smithy-client/spec/smithy-client/features_spec.rb
@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+require_relative '../spec_helper'
+
+module Smithy
+  module Client
+    describe Features do
+      describe '#clear' do
+        it 'clears features' do
+          Thread.current[:smithy_ruby_features] = ['test']
+          Features.clear
+          expect(Features.list).to be_empty
+        end
+      end
+
+      describe '#track' do
+        before(:each) { Features.clear }
+
+        it 'tracks and removes a feature' do
+          proc = proc { expect(Features.list).to eq(%w[A]) }
+          Features.track('A') { proc.call }
+          expect(Features.list).to be_empty
+        end
+
+        it 'tracks and removes multiple features' do
+          features = %w[A B C]
+          proc = proc { expect(Features.list).to eq(features) }
+          Features.track(*features) { proc.call }
+          expect(Features.list).to be_empty
+        end
+
+        it 'tracks and removes features in stack order' do
+          proc1 = proc do
+            Features.track('C') do
+              expect(Features.list).to eq(%w[A B C])
+            end
+            expect(Features.list).to eq(%w[A B])
+          end
+          proc2 = proc do
+            Features.track('B') do
+              expect(Features.list).to eq(%w[A B])
+              proc1.call
+            end
+            expect(Features.list).to eq(%w[A])
+          end
+          Features.track('A') { proc2.call }
+          expect(Features.list).to be_empty
+        end
+
+        it 'ensures that features are removed' do
+          proc = proc do
+            expect(Features.list).to eq(%w[A])
+            raise StandardError
+          end
+          begin
+            Features.track('A') { proc.call }
+          rescue StandardError
+            # ignore
+          end
+          expect(Features.list).to be_empty
+        end
+
+        it 'tracks features in multiple threads' do
+          Features.track('A') do
+            expect(Features.list).to eq(%w[A])
+            Thread.new do
+              expect(Features.list).to be_empty
+              Features.clear
+              Features.track('B') do
+                expect(Features.list).to eq(%w[B])
+              end
+              expect(Features.list).to be_empty
+            end.join
+            expect(Features.list).to eq(%w[A])
+          end
+          expect(Features.list).to be_empty
+        end
+      end
+    end
+  end
+end

From 40e44a4373b97dcb0ab194b93284f172e8dcf547 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Tue, 15 Jul 2025 15:12:56 -0700
Subject: [PATCH 07/10] Add list test

---
 gems/smithy-client/spec/smithy-client/features_spec.rb | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/gems/smithy-client/spec/smithy-client/features_spec.rb b/gems/smithy-client/spec/smithy-client/features_spec.rb
index 8ed43a53e..faff9dac8 100644
--- a/gems/smithy-client/spec/smithy-client/features_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/features_spec.rb
@@ -7,7 +7,7 @@ module Client
     describe Features do
       describe '#clear' do
         it 'clears features' do
-          Thread.current[:smithy_ruby_features] = ['test']
+          Thread.current[:smithy_ruby_features] = %w[A]
           Features.clear
           expect(Features.list).to be_empty
         end
@@ -76,6 +76,13 @@ module Client
           expect(Features.list).to be_empty
         end
       end
+
+      describe '#list' do
+        it 'lists all features' do
+          Thread.current[:smithy_ruby_features] = %w[A]
+          expect(Features.list).to eq(%w[A])
+        end
+      end
     end
   end
 end

From fa9011ce233149dbcc6d1724276a661f52355775 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Wed, 16 Jul 2025 09:23:18 -0700
Subject: [PATCH 08/10] Remove clear and refactor tests

---
 .../lib/smithy-client/features.rb             |   7 +-
 .../lib/smithy-client/plugins/retry_errors.rb |   4 +-
 .../lib/smithy-client/request.rb              |   1 -
 .../spec/smithy-client/features_spec.rb       | 100 +++++++-----------
 4 files changed, 41 insertions(+), 71 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/features.rb b/gems/smithy-client/lib/smithy-client/features.rb
index 7cccd4fd5..e5003cae8 100644
--- a/gems/smithy-client/lib/smithy-client/features.rb
+++ b/gems/smithy-client/lib/smithy-client/features.rb
@@ -4,18 +4,15 @@ module Smithy
   module Client
     # @api private
     module Features
-      def self.clear
-        Thread.current[:smithy_ruby_features] = []
-      end
-
       def self.track(*metrics, &block)
+        Thread.current[:smithy_ruby_features] ||= []
         Thread.current[:smithy_ruby_features].concat(metrics)
         block.call
       ensure
         Thread.current[:smithy_ruby_features].pop(metrics.size)
       end
 
-      def self.list
+      def self.tracked
         Thread.current[:smithy_ruby_features] || []
       end
     end
diff --git a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
index 481fa2dba..5cad4d8bc 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
@@ -120,8 +120,8 @@ def reset_response(context, response)
 
           def with_metric(retry_strategy, &block)
             case retry_strategy
-            when Retry::Standard then Features.track('RETRY_MODE_STANDARD') { block.call }
-            when Retry::Adaptive then Features.track('RETRY_MODE_ADAPTIVE') { block.call }
+            when Retry::Standard then Features.track('RETRY_MODE_STANDARD', &block)
+            when Retry::Adaptive then Features.track('RETRY_MODE_ADAPTIVE', &block)
             else block.call
             end
           end
diff --git a/gems/smithy-client/lib/smithy-client/request.rb b/gems/smithy-client/lib/smithy-client/request.rb
index 5d96c0bff..3c7d12045 100644
--- a/gems/smithy-client/lib/smithy-client/request.rb
+++ b/gems/smithy-client/lib/smithy-client/request.rb
@@ -9,7 +9,6 @@ class Request
       # @option options [HandlerList] :handlers (nil)
       # @option options [HandlerContext] :context (nil)
       def initialize(options = {})
-        Features.clear
         @handlers = options[:handlers] || HandlerList.new
         @context = options[:context] || HandlerContext.new
       end
diff --git a/gems/smithy-client/spec/smithy-client/features_spec.rb b/gems/smithy-client/spec/smithy-client/features_spec.rb
index faff9dac8..6f89bbaed 100644
--- a/gems/smithy-client/spec/smithy-client/features_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/features_spec.rb
@@ -5,83 +5,57 @@
 module Smithy
   module Client
     describe Features do
-      describe '#clear' do
-        it 'clears features' do
-          Thread.current[:smithy_ruby_features] = %w[A]
-          Features.clear
-          expect(Features.list).to be_empty
-        end
+      it 'tracks and removes a feature' do
+        Features.track('A') { expect(Features.tracked).to eq(%w[A]) }
+        expect(Features.tracked).to be_empty
       end
 
-      describe '#track' do
-        before(:each) { Features.clear }
-
-        it 'tracks and removes a feature' do
-          proc = proc { expect(Features.list).to eq(%w[A]) }
-          Features.track('A') { proc.call }
-          expect(Features.list).to be_empty
-        end
-
-        it 'tracks and removes multiple features' do
-          features = %w[A B C]
-          proc = proc { expect(Features.list).to eq(features) }
-          Features.track(*features) { proc.call }
-          expect(Features.list).to be_empty
-        end
+      it 'tracks and removes multiple features' do
+        features = %w[A B C]
+        Features.track(*features) { expect(Features.tracked).to eq(features) }
+        expect(Features.tracked).to be_empty
+      end
 
-        it 'tracks and removes features in stack order' do
-          proc1 = proc do
+      it 'tracks and removes features in stack order' do
+        Features.track('A') do
+          expect(Features.tracked).to eq(%w[A])
+          Features.track('B') do
+            expect(Features.tracked).to eq(%w[A B])
             Features.track('C') do
-              expect(Features.list).to eq(%w[A B C])
-            end
-            expect(Features.list).to eq(%w[A B])
-          end
-          proc2 = proc do
-            Features.track('B') do
-              expect(Features.list).to eq(%w[A B])
-              proc1.call
+              expect(Features.tracked).to eq(%w[A B C])
             end
-            expect(Features.list).to eq(%w[A])
+            expect(Features.tracked).to eq(%w[A B])
           end
-          Features.track('A') { proc2.call }
-          expect(Features.list).to be_empty
-        end
-
-        it 'ensures that features are removed' do
-          proc = proc do
-            expect(Features.list).to eq(%w[A])
-            raise StandardError
-          end
-          begin
-            Features.track('A') { proc.call }
-          rescue StandardError
-            # ignore
-          end
-          expect(Features.list).to be_empty
+          expect(Features.tracked).to eq(%w[A])
         end
+        expect(Features.tracked).to be_empty
+      end
 
-        it 'tracks features in multiple threads' do
+      it 'ensures that features are removed' do
+        begin
           Features.track('A') do
-            expect(Features.list).to eq(%w[A])
-            Thread.new do
-              expect(Features.list).to be_empty
-              Features.clear
-              Features.track('B') do
-                expect(Features.list).to eq(%w[B])
-              end
-              expect(Features.list).to be_empty
-            end.join
-            expect(Features.list).to eq(%w[A])
+            expect(Features.tracked).to eq(%w[A])
+            raise StandardError
           end
-          expect(Features.list).to be_empty
+        rescue StandardError
+          # ignore
         end
+        expect(Features.tracked).to be_empty
       end
 
-      describe '#list' do
-        it 'lists all features' do
-          Thread.current[:smithy_ruby_features] = %w[A]
-          expect(Features.list).to eq(%w[A])
+      it 'tracks features in multiple threads' do
+        Features.track('A') do
+          expect(Features.tracked).to eq(%w[A])
+          Thread.new do
+            expect(Features.tracked).to be_empty
+            Features.track('B') do
+              expect(Features.tracked).to eq(%w[B])
+            end
+            expect(Features.tracked).to be_empty
+          end.join
+          expect(Features.tracked).to eq(%w[A])
         end
+        expect(Features.tracked).to be_empty
       end
     end
   end

From a6d2a45d559f233e78c7030dbc4af536780b92e6 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Wed, 16 Jul 2025 09:30:29 -0700
Subject: [PATCH 09/10] Rename metric to feature

---
 .../lib/smithy-client/features.rb             | 20 ++++++++++---------
 .../plugins/request_compression.rb            |  4 ++--
 .../lib/smithy-client/plugins/retry_errors.rb |  4 ++--
 3 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/features.rb b/gems/smithy-client/lib/smithy-client/features.rb
index e5003cae8..f60321fd6 100644
--- a/gems/smithy-client/lib/smithy-client/features.rb
+++ b/gems/smithy-client/lib/smithy-client/features.rb
@@ -4,16 +4,18 @@ module Smithy
   module Client
     # @api private
     module Features
-      def self.track(*metrics, &block)
-        Thread.current[:smithy_ruby_features] ||= []
-        Thread.current[:smithy_ruby_features].concat(metrics)
-        block.call
-      ensure
-        Thread.current[:smithy_ruby_features].pop(metrics.size)
-      end
+      class << self
+        def track(*features, &block)
+          Thread.current[:smithy_ruby_features] ||= []
+          Thread.current[:smithy_ruby_features].concat(features)
+          block.call
+        ensure
+          Thread.current[:smithy_ruby_features].pop(features.size)
+        end
 
-      def self.tracked
-        Thread.current[:smithy_ruby_features] || []
+        def tracked
+          Thread.current[:smithy_ruby_features] || []
+        end
       end
     end
   end
diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index eb936b22b..e765369e3 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -77,7 +77,7 @@ def call(context)
                 end
               end
             end
-            with_metric(selected_encoding) { @handler.call(context) }
+            track_feature(selected_encoding) { @handler.call(context) }
           end
 
           private
@@ -149,7 +149,7 @@ def update_content_encoding(encoding, context)
             end
           end
 
-          def with_metric(encoding, &block)
+          def track_feature(encoding, &block)
             if encoding == 'gzip'
               Features.track('GZIP_REQUEST_COMPRESSION', &block)
             else
diff --git a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
index 5cad4d8bc..3c6561452 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/retry_errors.rb
@@ -84,7 +84,7 @@ def call(context)
           private
 
           def handle(context, retry_strategy, token)
-            response = with_metric(retry_strategy) { @handler.call(context) }
+            response = track_feature(retry_strategy) { @handler.call(context) }
             if (error = response.error)
               return response unless retryable?(context.http_request)
 
@@ -118,7 +118,7 @@ def reset_response(context, response)
             response.error = nil
           end
 
-          def with_metric(retry_strategy, &block)
+          def track_feature(retry_strategy, &block)
             case retry_strategy
             when Retry::Standard then Features.track('RETRY_MODE_STANDARD', &block)
             when Retry::Adaptive then Features.track('RETRY_MODE_ADAPTIVE', &block)

From 5141d2d60b26ce052be62d3bcf58cde9df2110dc Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Wed, 16 Jul 2025 11:18:30 -0700
Subject: [PATCH 10/10] PR comments

---
 .../lib/smithy-client/plugins/request_compression.rb           | 3 ++-
 gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb    | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index e765369e3..953f3d57f 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -150,7 +150,8 @@ def update_content_encoding(encoding, context)
           end
 
           def track_feature(encoding, &block)
-            if encoding == 'gzip'
+            case encoding
+            when 'gzip'
               Features.track('GZIP_REQUEST_COMPRESSION', &block)
             else
               block.call
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
index 98fd362ff..b343a08a6 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
@@ -7,7 +7,7 @@ module RpcV2Cbor
       class Handler < Client::Handler
         def call(context)
           build_request(context)
-          response = Features.track('PROTOCOL_RPC_V2_CBOR') { @handler.call(context) }
+          response = @handler.call(context)
           response.on_done(200..299) { |resp| resp.data = parse_body(context) }
           response
         end