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sh.status()

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  • Definition
  • Compatibility
  • Output Examples
  • Output Fields
sh.status()

When run on a mongos instance, prints a formatted report of the sharding configuration and the information regarding existing chunks in a sharded cluster. The default behavior suppresses the detailed chunk information if the total number of chunks is greater than or equal to 20.

The sh.status() method has the following parameter:

Parameter
Type
Description

verbose

boolean

Optional. Determines the level of verbosity.

If true, the method displays:

  • Full details of the chunk distribution across shards even if you have 20 or more chunks, as well as the number of chunks on each shard.

  • Details of active mongos instances.

If false, the method displays:

  • Full details of the chunk distribution across shards only if you have less than 20 chunks. If you have 20 or more chunks, the method instead returns a too many chunks to print ... message, showing only the number of chunks on each shard.

  • Only the version and number of active mongos instances.

The default verbose value is false.

Tip

See also:

This method is available in deployments hosted in the following environments:

  • MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

Important

This command is not supported in M0, M2, and M5 clusters. For more information, see Unsupported Commands.

The Sharding Version section displays information on the config database:

--- Sharding Status ---
sharding version: {
"_id" : <num>,
"minCompatibleVersion" : <num>,
"currentVersion" : <num>,
"clusterId" : <ObjectId>
}

The Shards section lists information on the shard(s). For each shard, the section displays the name, host, and the associated tags, if any.

shards:
{ "_id" : <shard name1>, "host" : <string>, "tags" : [ <string> ... ], "state" : <num> }
{ "_id" : <shard name2>, "host" : <string>, "tags" : [ <string> ... ], "state" : <num> }
...

The Active mongos Instances section displays, by default, information on the version and count of mongos instances that have been active within the last 60 seconds:

active mongoses:
<version> : <num>

If the method is run with the verbose parameter to true, the Active mongos Instances section displays additional information:

active mongoses:
{ "_id" : "<hostname:port>", "advisoryHostFQDNs" : [ "<name>" ], "mongoVersion" : <string>, "ping" : <ISODate>, "up" : <long>, "waiting" : <boolean> }

The Autosplit displays information on whether autosplit is enabled:

autosplit:
Currently enabled: <yes|no>

The Balancer section lists information about the state of the balancer. This provides insight into current balancer operation and can be useful when troubleshooting an unbalanced sharded cluster.

balancer:
Currently enabled: yes
Currently running: yes
Collections with active migrations:
config.system.sessions started at Fri May 15 2020 17:38:12 GMT-0400 (EDT)
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
416 : Success
1 : Failed with error 'aborted', from shardA to shardB

The Databases section lists information on the database(s). It displays the database name and the primary shard for each database.

databases:
{ "_id" : <dbname1>, "primary" : <string>, "version": <document> }
{ "_id" : <dbname2>, "primary" : <string>, "version": <document> }
...

The Sharded Collection section provides information on the sharding details for sharded collection(s). For each sharded collection, the section displays the shard key, the number of chunks per shard(s), the distribution of chunks across shards [1], and the tag information, if any, for shard key range(s).

<dbname>.<collection>
shard key: { <shard key> : <1 or hashed> }
unique: <boolean>
balancing: <boolean>
chunks:
<shard name1> <number of chunks>
<shard name2> <number of chunks>
...
{ <shard key>: <min range1> } -->> { <shard key> : <max range1> } on : <shard name> <last modified timestamp>
{ <shard key>: <min range2> } -->> { <shard key> : <max range2> } on : <shard name> <last modified timestamp>
...
tag: <tag1> { <shard key> : <min range1> } -->> { <shard key> : <max range1> }
...
sh.status.sharding-version._id

The _id is an identifier for the version details.

sh.status.sharding-version.minCompatibleVersion

The minCompatibleVersion is the minimum compatible version of the config server.

In MongoDB versions earlier than 6.2, this field is included in the config.version collection, but in mongosh 2.0.0 and later, the field is not returned in the sh.status() output. Starting in MongoDB 6.2, this field is removed and not returned in any mongosh version or other client application. Instead, to obtain version information, see the feature compatibility version (fcv).

sh.status.sharding-version.currentVersion

The currentVersion is the current version of the config server.

In MongoDB versions earlier than 6.2, this field is included in the config.version collection, but in mongosh 2.0.0 and later, the field is not returned in the sh.status() output. Starting in MongoDB 6.2, this field is removed and not returned in any mongosh version or other client application. Instead, to obtain version information, see the feature compatibility version (fcv).

sh.status.sharding-version.clusterId

The clusterId is the identification for the sharded cluster.

sh.status.active-mongoses

If verbose is false, sh.status.active-mongoses lists the version and count of the active mongos instances. Active mongos instances are mongos instances that have been pinged within the last 60 seconds.

If verbose is true, sh.status.active-mongoses returns a document for each active mongos instance containing the following fields:

Field
Data Type
Description

_id

String

The hostname and port where the mongos is running. The _id is formatted as <hostname>:<port>.

advisoryHostFQDNs

Array of strings

Array of the mongos's fully qualified domain names (FQDNs).

created

Date

When the mongos was started.

New in version 5.2.

mongoVersion

String

Version of MongoDB that the mongos is running.

ping

Date

mongos instances send pings to the config server every 30 seconds. This field indicates the last ping time.

up

NumberLong

Number of seconds the mongos has been up as of the last ping.

waiting

Boolean

This field is always true and is only included for backward compatibility.

active mongoses:
{
"_id" : "<hostname:port>",
"advisoryHostFQDNs" : [ "<name>" ],
"created" : <ISODate>,
"mongoVersion" : <string>,
"ping" : <ISODate>,
"up" : <long>,
"waiting" : <boolean>
}
...
sh.status.autosplit

sh.status.autosplit indicates whether autosplit is currently enabled.

Note

Starting in MongoDB 6.0.3, automatic chunk splitting is not performed. This is because of balancing policy improvements. Auto-splitting commands still exist, but do not perform an operation.

In MongoDB versions earlier than 6.1:

The mongo methods sh.enableBalancing(namespace) and sh.disableBalancing(namespace) have no affect on the auto-splitting.

sh.status.shards._id

The _id displays the name of the shard.

sh.status.shards.host

The host displays the host location of the shard.

sh.status.shards.tags

The tags displays all the tags for the shard. The field only displays if the shard has tags.

sh.status.shards.state

The state displays:

  • 0 if the shard is not shard aware.

  • 1 if the shard is shard aware.

Note

Starting in MongoDB 6.0.3, automatic chunk splitting is not performed. This is because of balancing policy improvements. Auto-splitting commands still exist, but do not perform an operation.

In MongoDB versions earlier than 6.1:

The mongo methods sh.enableBalancing(namespace) and sh.disableBalancing(namespace) have no affect on the auto-splitting.

sh.status.balancer.currently-enabled

currently-enabled indicates if the balancer is currently enabled on the sharded cluster.

sh.status.balancer.currently-running

currently-running indicates whether the balancer is currently running, and therefore currently balancing the cluster.

sh.status.balancer.collections-with-active-migrations

collections-with-active-migrations lists the names of any collections with active migrations, and specifies when the migration began. If there are no active migrations, this field will not appear in the sh.status() output.

sh.status.balancer.failed-balancer-rounds-in-last-5-attempts

failed-balancer-rounds-in-last-5-attempts displays the number of balancer rounds that failed, from among the last five attempted rounds. A balancer round will fail when a chunk migration fails.

sh.status.balancer.last-reported-error

last-reported-error lists the most recent balancer error message. If there have been no errors, this field will not appear in the sh.status() output.

sh.status.balancer.time-of-reported-error

time-of-reported-error provides the date and time of the most recently-reported error.

sh.status.balancer.migration-results-for-the-last-24-hours

migration-results-for-the-last-24-hours displays the number of migrations in the last 24 hours, and the error messages from failed migrations . If there have been no recent migrations, migration-results-for-the-last-24-hours displays No recent migrations.

migration-results-for-the-last-24-hours includes all migrations, including those not initiated by the balancer.

sh.status.databases._id

The _id displays the name of the database.

sh.status.databases.primary

The primary displays the primary shard for the database.

sh.status.databases.version

The version displays the version information for the database:

{ "uuid" : UUID("cc250b66-8638-49f7-a2e8-c6f1220b9d7a"), "lastMod" : 1 }

where:

  • uuid is the database identifier.

  • lastMod is the database version.

sh.status.databases.<collection>.shard-key

The shard-key displays the shard key specification document.

sh.status.databases.<collection>.unique

The unique displays whether MongoDB enforces uniqueness on the shard key values (i.e. whether the underlying shard key index is unique).

sh.status.databases.<collection>.balancing

Displays whether the balancer can balance the collection. If the balancer is enabled and this status returns true, the balancer includes this collection in balancing operations. If the status returns false, it indicates that the balancer does not balance data in this collection.

sh.status.databases.<collection>.chunks

The chunks lists all the shards and the number of chunks that reside on each shard.

sh.status.databases.<collection>.chunk-details

The chunk-details lists the details of the chunks [1]:

  • The range of shard key values that define the chunk,

  • The shard where the chunk resides, and

  • The last modified timestamp for the chunk.

sh.status.databases.<collection>.tag

The tag lists the details of the tags associated with a range of shard key values.

[1](1, 2) The sharded collection section, by default, displays the chunk information if the total number of chunks is less than 20. To display the information when you have 20 or more chunks, call the sh.status() methods with the verbose parameter set to true, i.e. sh.status(true).

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