Updating Meteor - question about Mongo

I am updating several Meteor apps from v1.3.4.1 to

I am a little confused as to whether the Mongo DB was automatically upgraded in the process.

I took a development version at v1.3.4.1, then progressively updated it to, 1.4, 1.5, then The only special step I had to do was 'meteor npm install --save babel_runtime after going to 1.5.
The result runs fine. When I do Meteor Mongo from a different linux shell it shows Mongo Shell 3.2.15. Does this mean the MongoDB is running Mongo 3.2 now and the DB has been upgraded as well?

I have done this for 4 apps. Is it now recommended I convert to wiredTiger for each app?

Wired tiger is on by default, and there’s a check to run to see if it’s on (wired tiger is a strap on sort of thing). Yes mongo shell 3.2 = mongodb 3.2.

When I run the development version it tells me that i should consider running wiredTiger. It doesn’t seem to be on.

So my next two questions are related…

  1. When I deploy the 4 apps (I use Meteor build deploy), should I deploy each app an upgrade at a time (, then 1.4, then 1.5, etc) or can I deploy the full upgrade to at once.

  2. The 4 separate apps use a single mongo shell on the deployment box, with different dbs for each app. Do I have to update all the dbs at the same time?

1 at once 2 no, I don’t even know where these questions come from nor I care much. do you know about the manual?

Which manual? I’ve never found much online about db upgrades when using meteor build deploy.

mongo manual/reference or stackoverflow. it looks like you still didn’t look up how to see wiredtiger enabled

I have found instructions on how to change the storageengine to wiredtiger for my development dbs, and have decided not to do that yet. I may do that for deployed dbs, though.

As for my deployed apps, all the dbs from the various METEOR apps are accessible from a single mongo command. I have yet to find any description of whether my dbs will work fine if I upgrade a single app to 3.2 but leave the other apps at 2.6. My instinct tells me I may need to migrate all my apps that use that mongo instance to 3.2 at the same time.