Merge pull request #35089 from eileencodes/fix-query-cache-for-database-switching

Invalidate all query caches for current thread

3 files changed, 48 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
index 8aeb934ec2..4e55fcae2f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
@@ -17,7 +17,7 @@ module ActiveRecord
           method_names.each do |method_name|
             base.class_eval <<-end_code, __FILE__, __LINE__ + 1
               def #{method_name}(*)
-                clear_query_cache if @query_cache_enabled
+                ActiveRecord::Base.clear_query_caches_for_current_thread if @query_cache_enabled
                 super
               end
             end_code
diff --git a/activerecord/lib/active_record/connection_handling.rb b/activerecord/lib/active_record/connection_handling.rb
index 558cdeccf2..53069cd899 100644
--- a/activerecord/lib/active_record/connection_handling.rb
+++ b/activerecord/lib/active_record/connection_handling.rb
@@ -176,6 +176,15 @@ module ActiveRecord
       config_hash
     end
 
+    # Clears the query cache for all connections associated with the current thread.
+    def clear_query_caches_for_current_thread
+      ActiveRecord::Base.connection_handlers.each_value do |handler|
+        handler.connection_pool_list.each do |pool|
+          pool.connection.clear_query_cache if pool.active_connection?
+        end
+      end
+    end
+
     # Returns the connection currently associated with the class. This can
     # also be used to "borrow" the connection to do database work unrelated
     # to any of the specific Active Records.
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 04bbc7d136..eb32b690aa 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -502,6 +502,44 @@ class QueryCacheTest < ActiveRecord::TestCase
     }.call({})
   end
 
+  def test_clear_query_cache_is_called_on_all_connections
+    skip "with in memory db, reading role won't be able to see database on writing role" if in_memory_db?
+    with_temporary_connection_pool do
+      ActiveRecord::Base.connection_handlers = {
+        writing: ActiveRecord::Base.default_connection_handler,
+        reading: ActiveRecord::ConnectionAdapters::ConnectionHandler.new
+      }
+
+      ActiveRecord::Base.connected_to(role: :reading) do
+        ActiveRecord::Base.establish_connection(ActiveRecord::Base.configurations["arunit"])
+      end
+
+      mw = middleware { |env|
+        ActiveRecord::Base.connected_to(role: :reading) do
+          @topic = Topic.first
+        end
+
+        assert @topic
+
+        ActiveRecord::Base.connected_to(role: :writing) do
+          @topic.title = "It doesn't have to be crazy at work"
+          @topic.save!
+        end
+
+        assert_equal "It doesn't have to be crazy at work", @topic.title
+
+        ActiveRecord::Base.connected_to(role: :reading) do
+          @topic = Topic.first
+          assert_equal "It doesn't have to be crazy at work", @topic.title
+        end
+      }
+
+      mw.call({})
+    end
+  ensure
+    ActiveRecord::Base.connection_handlers = { writing: ActiveRecord::Base.default_connection_handler }
+  end
+
   private
 
     def with_temporary_connection_pool