OPTIONS

sh.status()

Definition

sh.status()

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 Description
verbose 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 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 Wed Dec 10 2014 12:00:16 GMT+1100 (AEDT) by
          Pixl.local:27017:1418172757:16807:Balancer:282475249
      Collections with active migrations:
          test.t2 started at Wed Dec 10 2014 11:54:51 GMT+1100 (AEDT)
      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> }
   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.

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 lists the process that holds the balancer lock, and the date and time that the process obtained the lock.

If there is an active balancer lock, currently-running also reports the state of the balancer.

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.shard-key

The shard-key displays the shard key specification document.

sh.status.databases.chunks

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

sh.status.databases.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.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).