Push many documents using couchbase lite and sync gateway

First: thanks for your interest.

The solution I’m trying to build is syntetized here: Architectural information for a Server/Mobile app
Additional note:
I have two bucket “bucketsync” (used by the sync gateway) and “bucket” (shadow bucket).
“At present I’m thinking about writing those documents to the Server using the CouchBase SDK”… i mean writing in the shadowed bucket (“bucket”). I noticed that if i write documents to the shadowed bucket (“bucket”) they where updated by the sync gateway to his bucket (“bucketsync”).
Also consider that the logged documents are really important for this application, they could not be lost, I’m afraid because I do not know how to stop sync gateway to delete those “logged” documents from the shadowed bucket. I would like to mantain those documents once they where loaded.

Another alternative could be using a NodeJS (or other) to implement a RESTful service, just to write document I’ve to log in another bucket (not the one shadowed by the sync gateway, nor the sync gateway bucket, let’s say “bucketlog”), this way it would be fully external to the sync gateway world.

I hope I explained my question in the right way. If not, please ask me more.