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sh.status()

Definition

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.

See also

db.printShardingStatus()

Output Examples

The Sharding Version section displays information on the config database:

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--- 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.

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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:

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active mongoses:
  <version> : <num>

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

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

The Autosplit displays information on whether autosplit is enabled:

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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.

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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). For each database, the section displays the name, whether the database has sharding enabled, and the primary shard for the database.

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

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<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> }
   ...

Output Fields

Sharding Version

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.

sh.status.sharding-version.currentVersion

The currentVersion is the current version of the config server.

sh.status.sharding-version.clusterId

The clusterId is the identification for the sharded cluster.

Active mongos Instances

New in version 3.2.

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 ping’ed within the last 60 seconds.

If verbose is true, returns for each active mongos instance:

• Its hostname and port.
• An array of the instance’s fully qualified domain names (FQDNs).
• Its MongoDB version.
• Its most recent ping date and time.
• Its uptime since the last ping.
• Its waiting status.

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active mongoses:

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

Autosplit

sh.status.active-mongoses

sh.status.active-mongoses indicates whether autosplit is currently enabled.

Note

Starting in MongoDB 4.2:

• The balancerStart command and the mongo shell helper methods sh.startBalancer() and sh.setBalancerState(true) also enable auto-splitting for the sharded cluster.

  To disable auto-splitting when the balancer is enabled, you can use sh.disableAutoSplit().

• The balancerStop command and the mongo shell helper methods sh.stopBalancer() and sh.setBalancerState(false) also disable auto-splitting for the sharded cluster.

  To enable auto-splitting when the balancer is disabled, you can use sh.enableAutoSplit().

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

Shards

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

New in version 3.4.

The state displays:

• 0 if the shard is not shard aware.
• 1 if the shard is shard aware.

Balancer

Note

Starting in MongoDB 4.2:

• The balancerStart command and the mongo shell helper methods sh.startBalancer() and sh.setBalancerState(true) also enable auto-splitting for the sharded cluster.

  To disable auto-splitting when the balancer is enabled, you can use sh.disableAutoSplit().

• The balancerStop command and the mongo shell helper methods sh.stopBalancer() and sh.setBalancerState(false) also disable auto-splitting for the sharded cluster.

  To enable auto-splitting when the balancer is disabled, you can use sh.enableAutoSplit().

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.

Databases

sh.status.databases._id

The _id displays the name of the database.

sh.status.databases.partitioned

The partitioned displays whether the database has sharding enabled. If true, the database has sharding enabled.

sh.status.databases.primary

The primary displays the primary shard for the database.

sh.status.databases.version

New in version 4.0: Only available for featureCompatibilityVersion 4.0 or greater.

The version displays the version information for the database:

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

where:

• uuid is the database identifier.
• lastMod is the database version.

Sharded Collection

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).

New in version 3.2.

sh.status.databases.balancing

The balancing displays whether balancing is enabled (true) or disabled (false) for the collection.

New in version 3.2.

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.

See also

sh.balancerCollectionStatus()

[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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