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Enables auto-splitting for the sharded cluster. sh.enableAutoSplit() enables the autosplit flag in the config.settings collection.
Auto-splitting is enabled by default.
You can only run sh.enableAutoSplit() from a mongo shell connected to a mongos instance. sh.enableAutoSplit() errors if run on a mongod instance.
For more information on chunk splits, see Chunk Splits. For more information about how MongoDB balances chunks among shards, see: Manage Sharded Cluster Balancer and Sharded Cluster Balancer.