From 45a06a300e99be27f243508f14d11d6856f58bbd Mon Sep 17 00:00:00 2001
From: Matt-Yorkley <9029026+Matt-Yorkley@users.noreply.github.com>
Date: Fri, 26 Mar 2021 12:44:50 +0000
Subject: [PATCH 1/2] Update Exchange touch on Enterprise to use touch_later

This can improve issues with deadlocks where multiple touch calls are triggered in a single update, for example where an exchange touches it's parent enterprise on save, and we do this:

oc_with_lots_of_exchanges.exchanges.each{|ex| ex.clone! }
---
 app/models/exchange.rb | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/app/models/exchange.rb b/app/models/exchange.rb
index 01e23405a5..282173e622 100644
--- a/app/models/exchange.rb
+++ b/app/models/exchange.rb
@@ -12,7 +12,7 @@ class Exchange < ActiveRecord::Base
 
   belongs_to :order_cycle
   belongs_to :sender, class_name: 'Enterprise'
-  belongs_to :receiver, class_name: 'Enterprise', touch: true
+  belongs_to :receiver, class_name: 'Enterprise'
 
   has_many :exchange_variants, dependent: :destroy
   has_many :variants, through: :exchange_variants
@@ -23,6 +23,8 @@ class Exchange < ActiveRecord::Base
   validates :order_cycle, :sender, :receiver, presence: true
   validates :sender_id, uniqueness: { scope: [:order_cycle_id, :receiver_id, :incoming] }
 
+  after_save :touch_receiver
+
   accepts_nested_attributes_for :variants
 
   scope :in_order_cycle, lambda { |order_cycle| where(order_cycle_id: order_cycle) }
@@ -95,4 +97,10 @@ class Exchange < ActiveRecord::Base
   def participant
     incoming? ? sender : receiver
   end
+
+  def touch_receiver
+    return unless receiver&.persisted?
+
+    receiver.touch_later
+  end
 end

From 881e6dbac7fd5d42b8b542efb7ee59e6212577de Mon Sep 17 00:00:00 2001
From: Matt-Yorkley <9029026+Matt-Yorkley@users.noreply.github.com>
Date: Fri, 26 Mar 2021 13:01:33 +0000
Subject: [PATCH 2/2] Add more explicit touch spec for Exchange -> Enterprise

---
 spec/models/enterprise_caching_spec.rb | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/spec/models/enterprise_caching_spec.rb b/spec/models/enterprise_caching_spec.rb
index 01c1498046..e5506c46ab 100644
--- a/spec/models/enterprise_caching_spec.rb
+++ b/spec/models/enterprise_caching_spec.rb
@@ -92,6 +92,13 @@ describe Enterprise do
               enterprise.reload
             }.to change { enterprise.updated_at }
           end
+
+          it "touches enterprise when a relevant exchange is updated" do
+            expect {
+              oc.exchanges.first.update!(updated_at: Time.zone.now)
+              enterprise.reload
+            }.to change { enterprise.updated_at }
+          end
         end
 
         it "touches enterprise when the product's variant is added to order cycle" do