My target is to build an MQTT publish/subscribe like service by only exploiting Elasticsearch.
The case study scenario I would like to implement is this:
- User A create a message (document) inside the Elasticsearch index
- User B is warned and updated about the new message on the index.
I'm using plain java clients, since in Android I can't use the High Level Elastic search client. I have everything that allow me to send and read documents from the ES index, but I would like to find the best way to implement a subscription service for User B, without forcing him to poll for updates every few seconds.
About this I don't know where to start. I didn't find any trigger/websocket service available in ES. Please help with some ideas / documentation.