Production Cluster Architecture¶
In a production cluster, you must ensure that data is redundant and that your systems are highly available. To that end, a production cluster must have the following components:
Three config servers. Each config server must be on separate machines. A single sharded cluster must have exclusive use of its config servers. If you have multiple sharded clusters, you will need to have a group of config servers for each cluster.
Query Routers (mongos)¶
You may also deploy a group of mongos instances and use a proxy/load balancer between the application and the mongos. In these deployments, you must configure the load balancer for client affinity so that every connection from a single client reaches the same mongos.