Caching backend responses

Document updated on May 2, 2021

Sometimes you might want to reuse a previous response of a backend instead of asking for the same information over the network again. In this cases, it is possible to enable in-memory caching for the desired backend responses.

This caching technique applies to traffic between KrakenD and your microservices endpoints only and is not a caching system for the end-user endpoints. To enable the cache, you only need to add in the configuration file the httpcache middleware.

When enabled all connections for the configured backend are cached in-memory for the amount of time retrieved from the Cache-Control header of the response.

If you enable this module, you are required to be very aware of the response sizes, caching times and the hit-rate of the calls.

Enable the caching of the backend services in the backend section of your krakend.json with the middleware:

"github.com/devopsfaith/krakend-httpcache": {}

The middleware does not require additional configuration other than the simple inclusion.

See an example:

...
"backend": [
{
  "url_pattern": "/",
  "host": ["http://my-service.tld"],
  "extra_config": {
    "github.com/devopsfaith/krakend-httpcache": {}
  }
}
]

…