ASP.NET Core 2.0 Response Caching

Problem

How to cache responses in ASP.NET Core.

Solution

To an empty project, configure services and middleware for caching in Startup:

Create a controller, annotate with [ResponseCache] attribute:

The response will contain a Cache-Control header:

Response Caching - header

As you navigate between a controller with caching enabled (Home) and another one without it (Movies), you’ll notice that time isn’t been updated i.e. not coming from server but rather from cache:

Response Caching - output

Discussion

Response Caching middleware is responsible for storing and serving responses from a cache. It adds cache related headers to HTTP responses, primary one being Cache-Control.

Once middleware is setup, [ResponseCache] attribute is applied on controller/action to enable caching. The attribute has some useful parameters to alter the behaviour of middleware:

    • Duration: used to set cache expiry (in seconds).
    • Location: translates into Cache-Control header of public, private or no-cache.
    • VaryByQueryKeys: responses are cached based on query string parameters.
    • VaryByHeader: used to set Vary HTTP response header.
    • CacheProfileName: can point to cache profile setup in MVC middleware (see below).

Logging

You could enable logging to view the workings of the Response Caching middleware. Below is the first request to Home/Index (see highlighted lines), subsequent requests will go through this lifecycle, and serve the page from cache (until its expiry):

Response Caching - logging

Source Code

GitHub: https://github.com/TahirNaushad/Fiver.Perf.ResponseCaching

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