sh.addTagRange()¶

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Definition
Behavior
Example

Definition¶

sh.addTagRange(namespace, minimum, maximum, tag)¶

在 3.4 版更改: This method aliases to sh.updateZoneKeyRange() in MongoDB 3.4. The functionality specified below still applies to MongoDB 3.2. MongoDB 3.4 provides Zone sharding as the successor to tag-aware sharding.

Attaches a range of shard key values to a shard tag created using the sh.addShardTag() method. sh.addTagRange() takes the following arguments:

Parameter	Type	Description
`namespace`	string	The namespace of the sharded collection to tag.
`minimum`	document	The minimum value of the shard key range to include in the tag. The minimum is an inclusive match. Specify the minimum value in the form of `<fieldname>:<value>`. This value must be of the same BSON type or types as the shard key.
`maximum`	document	The maximum value of the shard key range to include in the tag. The maximum is an exclusive match. Specify the maximum value in the form of `<fieldname>:<value>`. This value must be of the same BSON type or types as the shard key.
`tag`	string	The name of the tag to attach the range specified by the `minimum` and `maximum` arguments to.

Use sh.addShardTag() to ensure that the balancer migrates documents that exist within the specified range to a specific shard or set of shards.

Only issue sh.addTagRange() when connected to a mongos instance.

Behavior¶

Bounds¶

Zone ranges are always inclusive of the lower boundary and exclusive of the upper boundary.

Dropped Collections¶

If you add a tag range to a collection using sh.addTagRange() and then later drop the collection or its database, MongoDB does not remove the tag association. If you later create a new collection with the same name, the old tag association will apply to the new collection.

Example¶

Given a shard key of {state: 1, zip: 1}, the following operation creates a tag range covering zip codes in New York State:

sh.addTagRange( "exampledb.collection",
                { state: "NY", zip: MinKey },
                { state: "NY", zip: MaxKey },
                "NY"
              )

← sh.addShardToZone() sh.updateZoneKeyRange() →