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- Production Cluster Architecture
Production Cluster Architecture¶
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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:
Components¶
Config Servers¶
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.
Shards¶
Two or more replica sets. These replica sets are the shards. For information on replica sets, see Replication.
Query Routers (mongos
)¶
One or more mongos
instances. The mongos
instances are the routers for the cluster. Typically, deployments have
one mongos
instance on each application server.
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
.
Because cursors and other resources are specific to an single
mongos
instance, each client must interact with only one
mongos
instance.