DOCS-15452-mongos-connection-pool (#1384)

Author: jason-price-mongodb

source/administration/connection-pool-overview.txt

@@ -163,7 +163,15 @@ Settings
        *Default*: ``1``. See 
        :parameter:`ShardingTaskExecutorPoolMinSize`.  
 
-       This setting only applies to sharded deployments.
+       Parameter only applies to sharded deployments.
+
+   * - :parameter:`ShardingTaskExecutorPoolMinSizeForConfigServers`
+
+     - .. include:: /includes/ShardingTaskExecutorPoolMinSizeForConfigServers-parameter.rst
+
+       *Default*: ``-1``
+
+       .. versionadded:: 4.4.16
 
    * - :parameter:`ShardingTaskExecutorPoolMaxSize` 
 
@@ -174,8 +182,16 @@ Settings
        *Default*: 2\ :sup:`64` - 1. See 
        :parameter:`ShardingTaskExecutorPoolMaxSize`.
 
-       This setting only applies to sharded deployments.
- 
+       Parameter only applies to sharded deployments.
+
+   * - :parameter:`ShardingTaskExecutorPoolMaxSizeForConfigServers`
+
+     - .. include:: /includes/ShardingTaskExecutorPoolMaxSizeForConfigServers-parameter.rst
+
+       *Default*: ``-1``
+
+       .. versionadded:: 4.4.16
+
 .. toctree::
    :titlesonly:
    :hidden:

source/includes/ShardingTaskExecutorPoolMaxSizeForConfigServers-parameter-example.rst

@@ -0,0 +1,4 @@
+.. |parameter| replace:: :parameter:`ShardingTaskExecutorPoolMaxSize`
+.. |maximum-or-minimum| replace:: maximum
+
+.. include:: /includes/ShardingTaskExecutorPoolSizeForConfigServers-parameter-example.rst

source/includes/ShardingTaskExecutorPoolMaxSizeForConfigServers-parameter.rst

@@ -0,0 +1,4 @@
+.. |parameter| replace:: :parameter:`ShardingTaskExecutorPoolMaxSize`
+.. |maximum-or-minimum| replace:: maximum
+
+.. include:: /includes/ShardingTaskExecutorPoolSizeForConfigServers-parameter.rst

source/includes/ShardingTaskExecutorPoolMinSizeForConfigServers-parameter-example.rst

@@ -0,0 +1,4 @@
+.. |parameter| replace:: :parameter:`ShardingTaskExecutorPoolMinSize`
+.. |maximum-or-minimum| replace:: minimum
+
+.. include:: /includes/ShardingTaskExecutorPoolSizeForConfigServers-parameter-example.rst

source/includes/ShardingTaskExecutorPoolMinSizeForConfigServers-parameter.rst

@@ -0,0 +1,4 @@
+.. |parameter| replace:: :parameter:`ShardingTaskExecutorPoolMinSize`
+.. |maximum-or-minimum| replace:: minimum
+
+.. include:: /includes/ShardingTaskExecutorPoolSizeForConfigServers-parameter.rst

source/includes/ShardingTaskExecutorPoolSizeForConfigServers-parameter-example.rst

@@ -0,0 +1,4 @@
+The following example sets |parameter| to ``2`` during startup, which
+sets the |maximum-or-minimum| number of outbound connections each
+TaskExecutor connection pool can open to a configuration server to
+``2``:

source/includes/ShardingTaskExecutorPoolSizeForConfigServers-parameter.rst

@@ -0,0 +1,13 @@
+Optional override for |parameter| to set the |maximum-or-minimum| number
+of outbound connections each TaskExecutor connection pool can open to a
+:ref:`configuration server <sharding-config-server>`.
+
+When set to:
+       
+- ``-1``, |parameter| is used. This is the default.
+       
+- an integer value greater than ``-1``, overrides the
+  |maximum-or-minimum| number of outbound connections each TaskExecutor
+  connection pool can open to a configuration server.
+
+Parameter only applies to sharded deployments.

source/reference/parameters.txt

@@ -2943,6 +2943,33 @@ Sharding Parameters
 
       :parameter:`ShardingTaskExecutorPoolMinSize`
 
+.. parameter:: ShardingTaskExecutorPoolMaxSizeForConfigServers
+
+   .. versionadded:: 4.4.16
+
+   Type: integer
+
+   Default: -1
+
+   |both|
+
+   .. include:: /includes/ShardingTaskExecutorPoolMaxSizeForConfigServers-parameter.rst
+
+   .. include:: /includes/ShardingTaskExecutorPoolMaxSizeForConfigServers-parameter-example.rst
+
+   .. code-block:: bash
+
+      mongos --setParameter ShardingTaskExecutorPoolMaxSizeForConfigServers=2
+
+   During runtime, you can also set the parameter with the
+   :dbcommand:`setParameter` command:
+
+   .. code-block:: javascript
+
+      db.adminCommand( { setParameter: 1, ShardingTaskExecutorPoolMaxSizeForConfigServers: 2 } )
+
+.. _sharding-pool-minsize-parameters:
+
 .. parameter:: ShardingTaskExecutorPoolMinSize
 
    Type: integer
@@ -2997,6 +3024,31 @@ Sharding Parameters
       - :parameter:`ShardingTaskExecutorPoolMaxSize`
       - :parameter:`warmMinConnectionsInShardingTaskExecutorPoolOnStartup`
 
+.. parameter:: ShardingTaskExecutorPoolMinSizeForConfigServers
+
+   .. versionadded:: 4.4.16
+
+   Type: integer
+
+   Default: -1
+
+   |both|
+
+   .. include:: /includes/ShardingTaskExecutorPoolMinSizeForConfigServers-parameter.rst
+
+   .. include:: /includes/ShardingTaskExecutorPoolMinSizeForConfigServers-parameter-example.rst
+
+   .. code-block:: bash
+
+      mongos --setParameter ShardingTaskExecutorPoolMinSizeForConfigServers=2
+
+   During runtime, you can also set the parameter with the
+   :dbcommand:`setParameter` command:
+
+   .. code-block:: javascript
+
+      db.adminCommand( { setParameter: 1, ShardingTaskExecutorPoolMinSizeForConfigServers: 2 } )
+
 .. parameter:: ShardingTaskExecutorPoolRefreshRequirementMS
 
    Type: integer