MongoDB with 100k concurrent connections

I need to run MongoDB that will support 100,000 concurrent connections
what is your suggestion?
use Amazon RDS?
use mms mongodb with some cluster?

if am using mms mongodb cluster, I should point the 100k users to the "main" server or create Amazon load balancer, add all the cluster servers to the Load balncer and point the connections to the Load balancer?

I need to run MongoDB that will support 100,000 concurrent connections
what is your suggestion?
use Amazon RDS?
use mms mongodb with some cluster?

Hi,

Proper capacity planning involves much more detail than "support 100k connections". You need to test & understand how your application & infrastructure will scale, consider your team's ability to manage your deployment, plan resources within constraints of time & budget, etc.

For example, for the database: is 100k connections the number of peak concurrent users hitting your application or database, or a guesstimated number of total users? How many requests are expected per user session, and what is the balance of reads vs writes? How much data will be transferred over the network for each connection? How do those reads & writes interact when your application is under load? How well provisioned are your servers relative to your data size and working set? The answers will be very specific to your deployment.

As a starting point for considerations, I would suggest Asya's webinar on capacity planning: http://www.mongodb.com/presentations/webinar-capacity-planning.