Add all_databases options or ability to specify multiple databases per river

[demetriusnunes]

I believe a really common use case for this river is to have a complete elasticsearch mirror of a mongodb database, in which you make all your writes to the mongodb servers and most of your reads out of elasticsearch.

When you have a lot of databases to manage, for instance, if you're a SaaS and you have a different database for each customer, managing the health of each river is a big pain.

So, why not have a simple a "mirror all databases" option? Anyone else care for that?

I'd be willing to implement it if I can get some initial help on how to get started.

[richardwilly98]

I am not sure if storing all databases in the same ES index is a common scenario. Also most of the time, database user are different.

[demetriusnunes]

You're right, the river would create one index for each database.