Mongo Sharding 101

gistfile1.txt

Follow this manual:

http://docs.mongodb.org/manual/tutorial/deploy-shard-cluster/

The sharding structure requires:

1. 3 config servers
2. a minimum of 2 mongoS instances (the mongoS is the server that does the balancing between the different mongods)
3. 9(!) mongod instances, 3 'standalone' mongods and for each standalone there are 3 replica sets for redundancy.
4. You cannot play with the above structure, yes, you really need 9 mongods.

Things to remember:
1. enable ntp on the machines since the system time is required to be the same on all machines
2. the mongoS instances needs to be with a load balancer between them to share the load.