(DOCS-12986): Add FAQ item for connection memory allocation (#1650)

* (DOCS-12986): Add FAQ item for connection memory allocation

* move faq item

* move faq item

* fix numeric formatting

* wording

* updates per review

* formatting

* remove extra bullet

* updates

* wording

* wording

* tweak

* wording

* wording

* wording

* incorporate edit from Alek

Author: jeff-allen-mongo

source/administration/connection-pool-overview.txt

@@ -74,6 +74,8 @@ cluster. The availability of connections to individual nodes within a
 sharded cluster affects latency. Operations must wait for a connection
 to be established.
 
+.. _connection-pool-settings:
+
 Connection Pool Configuration Settings
 --------------------------------------
 

source/faq/storage.txt

@@ -71,6 +71,33 @@ To what size should I set the WiredTiger internal cache?
 
 .. include:: /includes/extracts/wt-configure-cache.rst
 
+How much memory does MongoDB allocate per connection?
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Each connection uses up to 1 megabyte of RAM.
+
+To optimize memory use for connections, ensure that you:
+
+- Monitor the number of open connections to your deployment. Too many
+  open connections result in excessive use of RAM and reduce available
+  memory for the :term:`working set`.
+  
+- Close :ref:`connection pools <connection-pool-overview>` when they are
+  no longer needed. A connection pool is a cache of open, ready-to-use
+  database connections maintained by the driver. Closing unneeded pools
+  makes additional memory resources available.
+
+- Manage the size of your connection pool. The :urioption:`maxPoolSize`
+  connection string option specifies the maximum number of open
+  connections in the pool. By default, you can have up to 100 open
+  connections in the pool. Lowering the ``maxPoolSize`` reduces the
+  maximum amount of RAM used for connections.
+
+  .. tip::
+
+     To configure your connection pool, see
+     :ref:`connection-pool-settings`.
+
 How frequently does WiredTiger write to disk?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~