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- sh.updateZoneKeyRange()
sh.updateZoneKeyRange()¶
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Definition¶
-
sh.
updateZoneKeyRange
(namespace, minimum, maximum, zone)¶ New in version 3.4.
Associates a range of shard key values with a zone.
sh.updateZoneKeyRange()
takes the following arguments:Parameter Type Description namespace
string The namespace of the sharded collection associate with the
zone
.The collection must be sharded for the operation to succeed.
minimum
document The inclusive lower bound of the range of shard key values.
Specify each field of the shard key in the form of
<fieldname> : <value>
. The value must be of the same BSON type or types as the shard key.maximum
document The exclusive upper bound of the range of shard key values.
Specify each field of the shard key in the form of
<fieldname> : <value>
. The value must be of the same BSON type or types as the shard key.zone
string The name of the zone to associate with the range of shard key values bounded by minimum
andmaximum
.Only issue
sh.updateZoneKeyRange()
when connected to amongos
instance.
Behavior¶
You cannot create a range of shard key values whose lower and upper boundaries
overlap with an existing range for the sharded collection. For example, given
an existing range of 1
to 10
, you cannot create a new range of 5
to 20
, as the new range would overlap with the existing range.
A zone can have multiple ranges of data associated with it, but a range can at most be associated with a single zone.
See the zone manual page for more information on zones in sharded clusters.
Balancer¶
After associating a range to a zone, the balancer must first run in order to migrate any chunks whose ranges are covered by the zone to shards inside of that zone. Until balancing completes, some chunks may reside on the wrong shard given the configured zones for the sharded cluster. See Balancer for more information.
See the sharded cluster balancer manual page for more information on how migrations work in a sharded cluster.
Bounds¶
Zone ranges are always inclusive of the lower boundary and exclusive of the upper boundary.
Dropped Collections¶
If you add a zone range to a collection using sh.updateZoneKeyRange()
and
then later drop the collection or its database, MongoDB does not remove the
zone association. If you later create a new collection with the same name, the
old zone association applies to the new collection.
Security¶
For sharded clusters running with authentication, you must authenticate as either:
a user whose privileges include the specified actions on various collections in the
config
database:or, alternatively,
a user whose privileges include
enableSharding
on the cluster resource (available starting in version 3.6.16).
The clusterAdmin
or clusterManager
built-in roles have
the appropriate permissions for issuing sh.updateZoneKeyRange()
. See
the documentation page for Role-Based Access Control
for more information.
Example¶
Given a sharded collection exampledb.collection
with a shard key of { a
: 1 }
, the following operation creates a range with a lower bound of 1
and an upper bound of 10
on the alpha
zone:
The following operation removes the previously created range by passing
null
to the zone
field.
The min
and max
must match exactly the bounds of the target range.
The following operation attempts to remove the previously created range, but
specifies { a : 0 }
as the min
bound:
While the range of { a : 0 }
and { a : 10 }
encompasses the existing
range, it is not an exact match and therefore updateZoneKeyRange
does not remove anything.
Compound Shard Key¶
Given a sharded collection exampledb.collection
with a shard key of { a
: 1, b : 1 }
, the following operation creates a range covering the lower
bound of { a: 1, b : 1 }
and an upper bound of { a : 10, b : 10}
and associates it
with the alpha
zone:
See also