https://yakst.com/ja/posts/3243
App Engine PHP 7.2 Standard Env における Redis / Memcached / Spanner の利用方法
https://labs.gree.jp/blog/2018/08/17223/
AWS:ElasticCache
https://docs.aws.amazon.com/ja_jp/AmazonElastiCache/latest/mem-ug/elasticache-use-cases.html