I have few questions about sharding and replica sets:
- I am planning to write important logs to a sharded environment. about 100 million rows in a day, If I will connect to a single MONGOS process , wouldn't it be over loaded? can I define more entry points to the db?
- Can a config server be in the same servers as the sharded servers?
- if you look at this image : http://i.stack.imgur.com/lcp4X.png , in the bottom, 2 shards nodes that is a replica set. How come a shard be a replica set? isn't replica set is a full data node and a shard is a subset of the data? how can they be together?
here is what I don't get ):
"... A replica set is a group consisting of 1 primary and N secondaries. If you are sharding, each group will be a shard. That means that the single primary and all secondaries of the same group will have the same data (replicated)..."
From my understanding:
replica set is one primary that accepts all data.
Its data getting synced to the secondaries.
Sharding is a set of instances that accept subset of the data.
So, if replica set has all the data, and a shard has some data (on each server), how can they live together?