DOCSP-48388 break up faq

config/redirects

@@ -10,6 +10,7 @@ raw: ${prefix}/stable -> ${base}/current/
 [*-master]: ${prefix}/${version}/fundamentals/versioned-api/ -> ${base}/${version}/fundamentals/stable-api/
 [*-master]: ${prefix}/${version}/fundamentals/connection/lambda/ -> ${base}/${version}/fundamentals/connection/
 [*-master]: ${prefix}/${version}/fundamentals/csfle -> ${base}/${version}/fundamentals/encrypt-fields/
+[*-master]: ${prefix}/${version}/faq/ -> ${base}/${version}/
 
 [*-v5.0]: ${prefix}/${version}/quick-start/connect-to-mongodb/ -> ${base}/${version}/quick-start/
 [*-v5.0]: ${prefix}/${version}/quick-start/create-a-connection-string/ -> ${base}/${version}/quick-start/

source/connect/connection-options.txt

@@ -91,9 +91,9 @@ string, see :manual:`Connection Strings </reference/connection-string/>` in the
    * - **connectTimeoutMS**
      - non-negative integer
      - ``30000``
-     - Specifies the amount of time, in milliseconds, to wait to establish a single TCP
+     - Specifies the amount of time in milliseconds to wait to establish a single TCP
        socket connection to the server before raising an error. Specifying
-       ``0`` disables the connection timeout.
+       ``0``  means your application will use the operating system's default socket timeout value.
 
    * - **directConnection**
      - boolean
@@ -255,8 +255,9 @@ string, see :manual:`Connection Strings </reference/connection-string/>` in the
    * - **socketTimeoutMS**
      - non-negative integer
      - ``0``
-     - Specifies the amount of time, in milliseconds, spent attempting to send or receive on a
-       socket before timing out. Specifying ``0`` means no timeout.
+     - Specifies the amount of time in milliseconds spent attempting to send or receive
+       on a socket before timing out. Specifying ``0`` means your application will use the
+       operating system's default socket timeout value.
 
    * - **srvMaxHosts**
      - non-negative integer
@@ -343,6 +344,114 @@ string, see :manual:`Connection Strings </reference/connection-string/>` in the
        no compression, ``1`` signifies the fastest speed, and ``9`` signifies
        the best compression. See :ref:`node-network-compression` for more information.
 
+Connection Time Out Options
+---------------------------
+
+.. list-table::
+   :widths: 22 78
+   :header-rows: 1
+
+   * - Setting
+     - Description
+
+   * - **connectTimeoutMS**
+     - ``connectTimeoutMS`` is a :ref:`connection option
+       <node-connection-options>` that sets the time, in milliseconds,
+       for an individual connection from your connection pool to
+       establish a TCP connection to the {+mdb-server+} before
+       timing out. To modify the allowed time for 
+       `MongoClient.connect <{+api+}/classes/MongoClient.html#connect>`__ to establish a  
+       connection to a {+mdb-server+}, use the ``serverSelectionTimeoutMS`` option instead.
+
+       **Default:** 30000
+
+   * - **socketTimeoutMS**
+     - ``socketTimeoutMS`` specifies the amount of time the driver waits
+       for an inactive socket before closing it. The default value is to
+       never time out the socket. This option applies only to sockets that
+       have already been connected.
+
+   * - **maxTimeMS**
+     - `maxTimeMS <{+api+}/classes/FindCursor.html#maxTimeMS>`__
+       specifies the maximum amount of time that the server 
+       waits for an operation to complete after it has reached the
+       server. If an operation runs over the specified time limit, it
+       returns a timeout error. You can pass ``maxTimeMS`` only to an
+       individual operation or to a cursor.
+
+To specify the optional settings for your ``MongoClient``, declare one or
+more available settings in the ``options`` object of the constructor as
+follows:
+
+.. code-block:: javascript
+
+   const client = new MongoClient(uri, {
+     connectTimeoutMS: <integer value>,
+     socketTimeoutMS: <integer value>
+   });
+
+To see all the available settings, see the
+`MongoClientOptions <{+api+}/interfaces/MongoClientOptions.html>`__
+API Documentation.
+
+To specify ``maxTimeMS``, chain the ``maxTimeMS()`` method with a
+timeout specification to an operation that returns a ``Cursor``:
+
+.. code-block:: javascript
+
+   const cursor = myColl.find({}).maxTimeMS(50);
+
+Close Sockets After Connection
+------------------------------
+
+If you experience unexpected network behavior or if a MongoDB process
+fails with an error, you might not receive confirmation that the
+driver correctly closed the corresponding socket.
+
+To make sure that the driver correctly closes the socket in these cases,
+set the ``socketTimeoutMS`` option. When a MongoDB process times out, the driver
+will close the socket. We recommend that you select a value
+for ``socketTimeoutMS`` that is two to three times longer than the
+expected duration of the slowest operation that your application executes.
+
+Prevent Long-Running Operations From Slowing Down the Server
+------------------------------------------------------------
+
+You can prevent long-running operations from slowing down the server by
+specifying a timeout value. You can chain the ``maxTimeMS()`` method to
+an operation that returns a ``Cursor`` to set a timeout on a specific action.
+
+The following example shows how you can chain the ``maxTimeMS()`` method
+to an operation that returns a ``Cursor``:
+
+.. literalinclude:: /code-snippets/faq/maxTimeMS-example.js
+  :language: javascript
+
+.. _node-faq-keepalive:
+
+keepAlive Connection Option
+---------------------------
+
+The ``keepAlive`` connection option specifies whether to enable
+:wikipedia:`Transmission Control Protocol (TCP) keepalives
+<Keepalive#TCP_keepalive>` on a TCP socket. If you enable keepalives,
+the driver checks whether the connection is active by sending periodic pings
+to your MongoDB deployment. This functionality works only if your
+operating system supports the ``SO_KEEPALIVE`` socket option.
+
+The ``keepAliveInitialDelay`` option specifies the number of
+milliseconds that the driver waits before initiating a keepalive.
+
+The 5.3 driver version release deprecated these options. Starting in
+version 6.0 of the driver, the ``keepAlive`` option is permanently set
+to ``true``, and the ``keepAliveInitialDelay`` is set to 300000
+milliseconds (300 seconds).
+
+.. warning::
+
+   If your firewall ignores or drops the keepalive messages, you might
+   not be able to identify dropped connections.
+
 Additional Information
 ----------------------
 

source/connect/connection-options/connection-pools.txt

@@ -27,4 +27,115 @@ gets a connection from the pool, performs operations, and returns the connection
 to the pool for reuse.
 
 Connection pools help reduce application latency and the number of times new connections
-are created by {+driver-short+}.
+are created by {+driver-short+}.
+
+.. _node-faq-connection-pool:
+
+Connection Pool Overview
+-------------------------
+
+Every ``MongoClient`` instance has a built-in connection pool for each server
+in your MongoDB topology. Connection pools open sockets on demand to
+support concurrent requests to MongoDB in your application.
+
+The maximum size of each connection pool is set by the ``maxPoolSize`` option, which
+defaults to ``100``. If the number of in-use connections to a server reaches
+the value of ``maxPoolSize``, the next request to that server will wait
+until a connection becomes available.
+
+In addition to the sockets needed to support your application's requests,
+each ``MongoClient`` instance opens two more sockets per server
+in your MongoDB topology for monitoring the server's state.
+For example, a client connected to a three-node replica set opens six
+monitoring sockets. If the application uses the default setting for
+``maxPoolSize`` and only queries the primary (default) node, then
+there can be at most ``106`` total connections in the connection pool. If the
+application uses a :ref:`read preference <read-preference>` to query the
+secondary nodes, those connection pools grow and there can be
+``306`` total connections.
+
+To support high numbers of concurrent MongoDB requests
+within one process, you can increase ``maxPoolSize``.
+
+Connection pools are rate-limited. The ``maxConnecting`` option
+determines the number of connections that the pool can create in
+parallel at any time. For example, if the value of ``maxConnecting`` is
+``2``, the third request that attempts to concurrently check out a
+connection succeeds only when one the following cases occurs:
+
+- The connection pool finishes creating a connection and there are fewer
+  than ``maxPoolSize`` connections in the pool.
+- An existing connection is checked back into the pool.
+- The driver's ability to reuse existing connections improves due to
+  rate-limits on connection creation.
+
+You can set the minimum number of concurrent connections to
+each server with the ``minPoolSize`` option, which defaults to ``0``.
+The driver initializes the connection pool with this number of sockets. If
+sockets are closed, causing the total number
+of sockets (both in use and idle) to drop below the minimum, more
+sockets are opened until the minimum is reached.
+
+You can set the maximum number of milliseconds that a connection can
+remain idle in the pool by setting the ``maxIdleTimeMS`` option.
+Once a connection has been idle for ``maxIdleTimeMS``, the connection
+pool removes and replaces it. This option defaults to ``0`` (no limit).
+
+The following default configuration for a ``MongoClient`` works for most
+applications:
+
+.. code-block:: js
+
+   const client = new MongoClient("<connection string>");
+
+``MongoClient`` supports multiple concurrent requests. For each process,
+create a client and reuse it for all operations in a process. This
+practice is more efficient than creating a client for each request.
+
+The driver does not limit the number of requests that
+can wait for sockets to become available, and it is the application's
+responsibility to limit the size of its pool to bound queuing
+during a load spike. Requests wait for the amount of time specified in
+the ``waitQueueTimeoutMS`` option, which defaults to ``0`` (no limit).
+
+A request that waits more than the length of time defined by
+``waitQueueTimeoutMS`` for a socket raises a connection error. Use this
+option if it is more important to bound the duration of operations
+during a load spike than it is to complete every operation.
+
+When ``MongoClient.close()`` is called by any request, the driver
+closes all idle sockets and closes all sockets that are in
+use as they are returned to the pool. Calling ``MongoClient.close()``
+closes only inactive sockets and does not directly terminate
+any ongoing operations. The driver closes any in-use sockets only when
+the associated operations complete. However, the ``MongoClient.close()``
+method does close existing sessions and transactions, which might indirectly
+affect the behavior of ongoing operations and open cursors.
+
+Avoid Socket Timeouts
+---------------------
+
+Having a large connection pool does not always reduce reconnection
+requests. Consider the following example:
+
+An application has a connection pool size of 5 sockets and has the
+``socketTimeoutMS`` option set to 5000 milliseconds. Operations occur,
+on average, every 3000 milliseconds, and reconnection requests are
+frequent. Each socket times out after 5000 milliseconds, which means
+that all sockets must do something during those 5000 milliseconds to
+avoid closing.
+
+One message every 3000 milliseconds is not enough to keep the sockets
+active, so several of the sockets will time out after 5000 milliseconds.
+To avoid excessive socket timeouts, reduce the number of connections
+that the driver can maintain in the connection pool by specifying the
+``maxPoolSize`` option.
+
+To specify the optional ``maxPoolSize`` setting for your ``MongoClient``, declare
+it in the ``options`` object of the constructor as follows:
+
+.. code-block:: javascript
+
+   const client = new MongoClient(uri, {
+     maxPoolSize: <integer value>,
+   });