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Update an Existing Shard Zone
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After you specify a range of values for a shard zone, you can update the shard zone range if your application's requirements change.
To update an existing shard zone, perform these steps:
Stop the balancer.
Remove the old range from the zone.
Update the zone's range.
Restart the balancer.
About this Task
Zone ranges are inclusive of the lower boundary and exclusive of the upper boundary.
After you modify a zone, the balancer must migrate chunks to the appropriate zones based on the new range of values. Until balancing completes, some chunks may reside on the wrong shard given the configured zones for the sharded cluster.
Before you Begin
To complete this tutorial, you must deploy a sharded cluster with a sharded collection and create a zone to modify.
This example uses a sharded collection named users in the
records database, sharded by the zipcode field.
Add a shard to a zone called NYC
sh.addShardToZone(<shard name>, "NYC")
Specify a range of zipcode values for the NYC zone
sh.updateZoneKeyRange("records.users", { zipcode: "10001" }, { zipcode: "10281" }, "NYC" )
Steps
The following procedure modifies the range of zipcode values for the
NYC zone to be 11201 through 11240.
Stop the balancer
sh.stopBalancer()
Remove the current NYC range from the zone
sh.removeRangeFromZone("records.user", { zipcode: "10001" }, { zipcode: "10281" } )
Update the zone key range for the NYC zone
sh.updateZoneKeyRange("records.users", { zipcode: "11201" }, { zipcode: "11240" }, "NYC" )
Restart the balancer
sh.startBalancer()