The memcached module allows to expose elasticsearch API over the memcached protocol (as closely as possible).
It is provided as a plugin called transport-memcached and installing is as simply as executing plugin -install transport-memcached or downloading the memcached plugin and placing it under the plugins directory.
The memcached protocol supports both the binary and the text protocol, automatically detecting the correct one to use.
Memcached commands are mapped to REST and handled by the same generic REST layer in elasticsearch. Here is a list of the memcached commands supported:
GET
The memcached GET command maps to a REST GET. The key used is the URI (with parameters). The main downside is the fact that the memcached GET does not allow body in the request (and SET does not allow to return a result...). For this reason, most REST APIs (like search) allow to accept the “source” as a URI parameter as well.
SET
The memcached SET command maps to a REST POST. The key used is the URI (with parameters), and the body maps to the REST body.
The memcached DELETE command maps to a REST DELETE. The key used is the URI (with parameters).
The memcached QUIT command is supported and disconnects the client.
The following are the settings the can be configured for memcached:
| Setting | Description |
|---|---|
| memcached.port | A bind port range. Defaults to 11211-11311. |
It also shares the uses the common network settings.
The memcached module can be completely disabled and not started using by setting memcached.enabled to false. By default it is enabled once it is detected as a plugin.