Any Ideas how to use this when I have multiple mongodb databases on multiple servers?

[plotti]

I've read that the "river" plugin https://github.com/richardwilly98/elasticsearch-river-mongodb might be of some use, where It tails the log and applies the changes to elasticsearch.

I am generally a bit confused if I should rather have multiple mongodb databases and then collect them into one elasticsearch interface or if I should have one mongodb database and collect in in a cluster of elasticsearch nodes?. Anybody has some suggestions?

I understood that my options so far without taking something new are deploying the elasticsearch on another server than the mongodb to provide some sort of scalability. But this is still rather a 1:1 system.