sh.status()

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Definition

Output Examples
Output Fields

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`.

Tip

Output Examples

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>, "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).

<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

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	As of MongoDB 3.4, this field is always `true` and is only present for backward compatibility.

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

Autosplit

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

Note

Starting in MongoDB 6.1, automatic chunk splitting is not performed. This is because of balancing policy improvements. Auto-splitting commands still exist, but do not perform an operation. For details, see Balancing Policy Changes.

In MongoDB versions earlier than 6.1:

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

The state displays:

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

Balancer

Note

In MongoDB versions earlier than 6.1:

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: Starting in MongoDB 6.0 and feature compatibility version (fCV) 6.0, the partitioned flag only maintains backward compatibility with previous versions. By default, all databases are enabled for sharding regardless of the partitioned value.

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.

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).

sh.status.databases.<collection>.balancing: The balancing displays whether balancing is enabled (true) or disabled (false) for the 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.

sh.status()

Definition

Tip

See also:

Output Examples

Output Fields

Sharding Version

Active `mongos` Instances

Autosplit

Note

Shards

Balancer

Note

Databases

Sharded Collection

Tip

See also:

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Definition

Tip

See also:

Output Examples

Output Fields

Sharding Version

Active mongos Instances

Autosplit

Note

Shards

Balancer

Note

Databases

Sharded Collection

Tip

See also:

sh.status()

Active `mongos` Instances