MongoDB self-hosted, Mongo DB Atlas, Mongo DB on AWS comparison

Question

I think the 3 options to for MongoDB are : MongoDB self-hosted (Enterprise Advanced), Mongo DB Atlas, Mongo DB on AWS

Cost wise I am trying to see which is more effective.

Mongo DB enterprise advanced the cost aspect is not given and contact sales did not get any response. Is there any information on the cost (a ballpark number). Keeping this cost apart for license, the infra cost I am calculating as :

3 * r7i.xlarge (us-east) + 2 * 1 TB SSD gp3 + S3 backup ~ 629.08 + 23.55 ~ 700 $

(I have to account man-hours for maintenance, deploy etc but just as base.)

The other 2 options from going through web seemed MongoDB Atlas straightforward (managed by MongoDB), but here the cost is coming to :

M40 | 1 TB | $1.60| $1148.076

The option 3) MongoDB on AWS . I assumed it was marketplace offering (AWS or thirdparty managing MongoDB). But this goes to mongodb-on-aws which seems to lead to Atlas itself. This comes to around $1148.076 considering an equivalent M40 tier .

M40 | 1 TB | $1.60| $1148.076

Questions:

1. Is this estimation correct for a mid-range enterprise (data volume could increase but throughput requirements are consistent and on the lower end, but PII data hence security and other aspects are relevant).
2. Is there any MongoDB on AWS offering now (other than Atlas with hosting cloud as AWS).
3. Any advise on production cost of a typical medium enterprise SASS application with memory intensive, low CPU workload or comparisons (for low/free tier range Atlas seems to be good but then for scale as per general reading Atlas seems expensive hence checking what to expect in mid-range and how to possibly lower the cost)
4. Cost factors for Enterprise advanced offering.

Thank you.

Answer 1

It depends what you understand as "typical medium enterprise"

AWS offers their own MongoDB, they name it DocumentDB and it is compatible to MongoDB. However, AWS DocumentDB does not provide the full set of features as MongoDB does.

MongoDB Enterprise has two license models. The first model is based on the amount of total amount of RAM you have installed at your MongoDB the data bearing nodes (i.e. mongos roters, config server and arbiter node do not cost anything)

The second model I don't remember anymore, either it was based on the amount of data or number of hosts.