ruby-on-rails - Rails Parellel gem: ActiveRecord::StatementInvalid: Mysql2::Error: MySQL server has gone away

Question

我的 Rails 应用程序中有以下代码

results = Parallel.map(user_ids, :in_processes => 4) do |user_id|
  <some calculations>
  [user_id, result]
end

这在开发环境中正常工作。但是当我尝试测试包含此代码的方法时，测试失败ActiveRecord::StatementInvalid: Mysql2::Error: MySQL server has gone away

任何帮助深表感谢！