sh.status()¶

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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. If `true`, the method displays details of the document distribution across chunks when you have 20 or more chunks.

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 mongos Version and Count section displays information on the version and count of active mongos instances:

active mongoses:
  <version> : <num>

The Autosplit displays information on whether autosplit is enabled:

autosplit:
  Currently enabled: <yes|no>

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

New in version 3.0.0: 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
          Balancer lock taken at Fri Nov 11 2016 14:23:24 GMT-0500 (EST) by ConfigServer:Balancer
      Collections with active migrations:
          chat.messages started at Fri Nov 11 2016 14:24:12 GMT-0500 (EST)
      Failed balancer rounds in last 5 attempts:  1
      Last reported error:  tag ranges not valid for: test.t2
      Time of Reported error:  Wed Dec 10 2014 12:00:33 GMT+1100 (AEDT)
      Migration Results for the last 24 hours:
          96 : Success
          15 : Failed with error 'ns not found, should be impossible', from
          shard01 to shard02

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.

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

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 documents across chunks [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.

`mongos` Version and Count¶

sh.status.active-mongoses¶: sh.status.active-mongoses lists the version and count of the mongos instances.

Autosplit¶

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

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.

Balancer¶

New in version 3.0.0: sh.status() added the balancer field.

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.

If the balancer is running, currently-running prints information on the "balancer" lock.

Changed in version Starting: in 3.4

The primary of the CSRS config server holds the "balancer" lock, using a process id named "ConfigServer", which is never released.

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.

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.

sh.status.databases.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.

[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)`.

← sh.startBalancer() sh.stopBalancer() →