FIX: Thread safety issues with multisite:migrate and SeedFu.

db/fixtures/001_refresh.rb

@@ -1,8 +1,19 @@
 # frozen_string_literal: true
 
-# fix any bust caches post initial migration
-ActiveRecord::Base.connection.tables.each do |table|
-  table.classify.constantize.reset_column_information rescue nil
+class SeedData::Refresher
+  def self.refresh!
+    return if @refreshed
+
+    # Fix any bust caches post initial migration
+    # Not that reset_column_information is not thread safe so we have to becareful
+    # not to run it concurrently within the same process.
+    ActiveRecord::Base.connection.tables.each do |table|
+      table.classify.constantize.reset_column_information rescue nil
+    end
+
+    @refreshed = true
+  end
 end
 
+SeedData::Refresher.refresh!
 SiteSetting.refresh!