Idempotency

Idempotence is an important concept in the HTTP specification that states idempotent HTTP requests will result in the same state on the server no matter how many times that same request is executed. GET, HEAD, PUT, and DELETE all have this attribute, but POST does not.

PUT vs. POST in REST

• https://stackoverflow.com/posts/32524385/revisions
• https://stackoverflow.com/questions/630453/put-vs-post-in-rest
• http://blog.ploeh.dk/2014/08/11/cqs-versus-server-generated-ids/
• https://softwareengineering.stackexchange.com/questions/287163/generation-of-ids-in-offline-online-application
• https://www.clever-cloud.com/blog/engineering/2015/05/20/why-auto-increment-is-a-terrible-idea/
• https://stackoverflow.com/questions/15159274/avoid-duplicate-posts-with-rest
• https://stormpath.com/blog/put-or-post