This chapter showed you how to monitor and manage the sharded cluster. You learned about creating zones based on the shard key, and how to manage the sharded cluster balancer, adjust chunk sizes, and split a chunk. This was followed by a discussion of the impact of sharding on your backup strategy.Â
The last section covered the impact of a sharded cluster on application code. You learned, first of all, that the application must connect to a mongos instance in order to reach the entire sharded collection. You then learned that database read operations experience improved performance if the shard key is included in the query. Likewise, you learned that it's best to include the shard key in the query document associated with update and delete operations.
