Difference between PUT vs POST from a system administrator POV?

[oslon]

TL;DR

Difference between PUT vs POST from a system administrator POV?

I believe it’s important to learn concepts from a POV of X, when trying to learn something very confusing that could mean multiple meanings.

These are what I wrote in my college notes of TCP IP that I did 6 years ago.

Much of it is confusing as both seem to be doing the same thing.
Can you tell me what’s the benefit of being idempotent? As far as I know idempotent means no matter how many times you repeat a input, you get same output.

 

[jack action]

With PUT /path, the server accepts the data and MUST store it in /path. Making the same request again will overwrite everything in /path.

Then we can do:

GET /path to retrieve existing data;
DELETE /path to delete existing data;
PATCH /path to update only part of existing data.

I guess it makes more sense if one views these as applied to files on a server.

Initially POST was supposed to create a new set of data such as POST /customers or POST /articles for creating new customers or articles, but without identifying a URI to reach it (such as GET /article/{article-id} or GET /article?id={article-id}); it may not have one at all. You were supposed - but not obligated - to add an item to an already existing collection normally defined as /path.

With POST /path, the server accepts the data and does whatever it wants with it. This flexibility lead to use it for simulating a PUT, GET, DELETE, or PATCH with it.

 

[Mark44]

TL;DR Summary: Difference between PUT vs POST from a system administrator POV?

These are what I wrote in my college notes of TCP IP that I did 6 years ago.

TCP is a lower layer of the internet protocol, the transport layer. PUT and POST are commands one layer up in the application layer, including such protocols as HTTP, HTTPS, and others.

From this page -- https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PUT -- it says:

PUT
The HTTP PUT request method creates a new resource or replaces a representation of the target resource with the request payload.

The difference between PUT and POST is that PUT is idempotent: calling it once or several times successively has the same effect (that is no side effect), whereas successive identical POST requests may have additional effects, akin to placing an order several times.

 

[pbuk]

Can you tell me what’s the benefit of being idempotent?

Nothing bad happens if (perhaps due to a communications error) the message is processed more than once.