sh.status.txt

===========
sh.status()
===========

.. default-domain:: mongodb

.. contents:: On this page
   :local:
   :backlinks: none
   :depth: 1
   :class: singlecol

Definition
----------

.. start-include-here

.. method:: sh.status()

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

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

   .. list-table::
      :header-rows: 1
      :widths: 20 20 80
   
      * - 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 :ref:`active mongos instances
            <sharding-status-mongoses>`.
                                
          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 :ref:`version and number of active mongos
            instances <sharding-status-mongoses>`.

          The default verbose value is ``false``.

   .. seealso:: :method:`db.printShardingStatus()`

.. end-include-here

Output Examples
---------------

The :ref:`sharding-status-version-fields` section displays information on the
:term:`config database`:

.. code-block:: javascript

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

The :ref:`sharding-status-shards-fields` section lists information on
the shard(s). For each shard, the section displays the name, host, and
the associated tags, if any.

.. code-block:: javascript

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

The :ref:`sharding-status-mongoses` section displays, by default,
information on the version and count of :binary:`~bin.mongos` instances
that have been active within the last 60 seconds:

.. code-block:: javascript

   active mongoses:
     <version> : <num>

If the method is run with the ``verbose`` parameter to true, the
:ref:`sharding-status-mongoses` section displays additional information:

.. code-block:: javascript

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

.. versionadded:: 3.0.0
   The :ref:`sharding-status-balancer-fields` section lists information
   about the state of the :term:`balancer`. This provides insight into
   current balancer operation and can be useful when troubleshooting an
   unbalanced sharded cluster.

   .. code-block:: none

      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 :ref:`sharding-status-databases-fields` section lists information
on the database(s). For each database, the section displays the name,
whether the database has sharding enabled, and the :term:`primary
shard` for the database.

.. code-block:: javascript

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

The :ref:`sharding-status-collection-fields` 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
[#chunk-details]_, and the tag information, if any, for shard key
range(s).

.. code-block:: javascript

   <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-status-version-fields:

Sharding Version
~~~~~~~~~~~~~~~~

.. data:: sh.status.sharding-version._id

   The :data:`~sh.status.sharding-version._id` is an identifier
   for the version details.

.. data:: sh.status.sharding-version.minCompatibleVersion

   The :data:`~sh.status.sharding-version.minCompatibleVersion` is
   the minimum compatible version of the config server.

.. data:: sh.status.sharding-version.currentVersion

   The :data:`~sh.status.sharding-version.currentVersion` is
   the current version of the config server.

.. data:: sh.status.sharding-version.clusterId

   The :data:`~sh.status.sharding-version.clusterId` is the
   identification for the sharded cluster.

.. _sharding-status-mongoses:

Active ``mongos`` Instances
~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. versionadded:: 3.2

.. data:: sh.status.active-mongoses

   If ``verbose`` is ``false``, :data:`sh.status.active-mongoses` lists
   the version and count of the active :binary:`~bin.mongos` instances.
   Active :binary:`~bin.mongos` instances are :binary:`~bin.mongos`
   instances that have been ping'ed within the last 60 seconds.

   If ``verbose`` is ``true``, returns for each active  :binary:`~bin.mongos`  instance:
   
   - Its hostname and port.
   
   - Its most recent ping date and time.
   
   - Its uptime since the last ping.
   
   - Its waiting status.

   - Its MongoDB version.
   
   .. code-block:: javascript

      active mongoses:

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

.. _sharding-status-shards-fields:

Shards
~~~~~~

.. data:: sh.status.shards._id

   The :data:`~sh.status.shards._id` displays the name of the shard.

.. data:: sh.status.shards.host

   The :data:`~sh.status.shards.host` displays the host location
   of the shard.

.. data:: sh.status.shards.tags

   The :data:`~sh.status.shards.tags` displays all the tags for
   the shard. The field only displays if the shard has tags.

.. _sharding-status-balancer-fields:

Balancer
~~~~~~~~

.. versionadded:: 3.0.0
   :method:`sh.status()` added the ``balancer`` field.

.. data:: sh.status.balancer.currently-enabled

   :data:`~sh.status.balancer.currently-enabled` indicates if the
   :term:`balancer` is currently enabled on the sharded cluster.

.. data:: sh.status.balancer.currently-running

   :data:`~sh.status.balancer.currently-running` indicates whether
   the :term:`balancer` is currently running, and therefore currently
   balancing the cluster.

   If the :term:`balancer` is running,
   :data:`~sh.status.balancer.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,
   :data:`~sh.status.balancer.currently-running` also reports the
   state of the balancer.

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

   :data:`~sh.status.balancer.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 :method:`sh.status()`
   output.

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

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

.. data:: sh.status.balancer.last-reported-error

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

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

   :data:`~sh.status.balancer.time-of-reported-error` provides
   the date and time of the most recently-reported error.

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

   :data:`~sh.status.balancer.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,
   :data:`~sh.status.balancer.migration-results-for-the-last-24-hours`
   displays ``No recent migrations``.

   :data:`~sh.status.balancer.migration-results-for-the-last-24-hours`
   includes *all* migrations, including those not initiated by the balancer.

.. _sharding-status-databases-fields:

Databases
~~~~~~~~~

.. data:: sh.status.databases._id

   The :data:`~sh.status.databases._id` displays the name of the database.

.. data:: sh.status.databases.partitioned

   The :data:`~sh.status.databases.partitioned` displays whether
   the database has sharding enabled. If ``true``, the database has
   sharding enabled.

.. data:: sh.status.databases.primary

   The :data:`~sh.status.databases.primary` displays the
   :term:`primary shard` for the database.

.. _sharding-status-collection-fields:

Sharded Collection
~~~~~~~~~~~~~~~~~~

.. data:: sh.status.databases.shard-key

   The :data:`~sh.status.databases.shard-key` displays the shard
   key specification document.

.. data:: sh.status.databases.<collection>.unique

   The :data:`~sh.status.databases.<collection>.unique` displays
   whether MongoDB enforces uniqueness on the shard key values (i.e.
   whether the underlying shard key index is unique).

   .. versionadded:: 3.2

.. data:: sh.status.databases.<collection>.balancing

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

   .. versionadded:: 3.2

.. data:: sh.status.databases.<collection>.chunks

   The :data:`~sh.status.databases.<collection>.chunks` lists all the shards
   and the number of chunks that reside on each shard.

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

   The :data:`~sh.status.databases.chunk-details` lists the details
   of the chunks [#chunk-details]_:

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

   - The shard where the chunk resides, and

   - The last modified timestamp for the chunk.

.. data:: sh.status.databases.tag

   The :data:`~sh.status.databases.tag` lists the details of
   the tags associated with a range of shard key values.

.. [#chunk-details] 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 :method:`sh.status()` methods with the ``verbose`` parameter
   set to ``true``, i.e. ``sh.status(true)``.