I would like to ask a few questions about sharding, they are as follows:
In a sharded cluster are query routers separate nodes? How are they set up from what I have seen the shareded clusters are configured by setting up the Conf Server and then adding and enabling shards and their DBs or Collections?
Are each Shard and Conf Server a Replicate Set? If so do you have to add all members of a replicate set in Shard Cluster or can you add primary or secondary nodes by themselves?
Other than commands like
sh.status()what are methods of checkup can you do to make sure the sharded cluster is working as expected? For example, there arent any hardware issues that are setting the cluster back etc.