DOCS-4483

source/administration/production-notes.txt

@@ -459,6 +459,38 @@ MongoDB's performance and ease of use. For more information, see
 `this blog post
 <http://www.mongodb.com/blog/post/provisioned-iops-aws-marketplace-significantly-boosts-mongodb-performance-ease-use>`_.
 
+Azure
+`````
+For all MongoDB deployments using Azure, you **must** mount volume
+that hosts the :program:`mongod` instance's :setting:`~storage.dbPath`
+with the *Host Cache Preference* ``READ/WRITE``.
+
+This applies to all Azure deployments, using any guest operating
+system.
+
+If your volumes have inappropriate cache settings, MongoDB may
+eventually shut down with the following error:
+
+.. code-block:: none
+
+   [DataFileSync] FlushViewOfFile for <data file> failed with error 1 ...
+   [DataFileSync] Fatal Assertion 16387
+
+These shut downs do not produce data loss if when
+:setting:`storage.journal.enabled` is set to ``true``. You can safely
+restart :program:`mongod` at any time following this event.
+
+The performance characteristics of MongoDB may change with
+``READ/WRITE`` caching enabled.
+
+The TCP keepalive on the Azure load balancer is 240 seconds by
+default, which can cause it to silently drop connections if the TCP
+keepalive on your Azure systems is greater than this value.  You
+should set ``tcp_keepalive_time`` to 120 to ameliorate this problem.
+
+.. include:: /includes/fact-tcp-keepalive-linux.rst
+.. include:: /includes/fact-tcp-keepalive-windows.rst
+
 VMWare
 ``````
 

source/faq/diagnostics.txt

@@ -38,52 +38,21 @@ TCP keep alive value, which Linux systems store as the
 ``tcp_keepalive_time`` value. A common keep alive period is ``7200``
 seconds (2 hours); however, different distributions and OS X may have
 different settings. For MongoDB, you will have better experiences with
-shorter keepalive periods, on the order of ``300`` seconds (five minutes).
+shorter keepalive periods, on the order of ``120`` seconds (two minutes).
 
-On Linux systems you can use the following operation to check the
-value of ``tcp_keepalive_time``:
-
-.. code-block:: sh
-
-   cat /proc/sys/net/ipv4/tcp_keepalive_time
-
-You can change the ``tcp_keepalive_time`` value with the following
-operation:
-
-.. code-block:: sh
-
-   echo 300 > /proc/sys/net/ipv4/tcp_keepalive_time
+.. include:: /includes/fact-tcp-keepalive.rst
 
 The new ``tcp_keepalive_time`` value takes effect without requiring
 you to restart the :program:`mongod` or :program:`mongos`
 servers. When you reboot or restart your system you will need to set
 the new ``tcp_keepalive_time`` value, or see your operating system's
 documentation for setting the TCP keepalive value persistently.
 
-For OS X systems, issue the following command to view the keep alive
-setting:
-
-.. code-block:: sh
-
-   sysctl net.inet.tcp.keepinit
-
-To set a shorter keep alive period use the following invocation:
-
-.. code-block:: sh
-
-   sysctl -w net.inet.tcp.keepinit=300
-
 If your replica set or sharded cluster experiences keepalive-related
 issues, you must alter the ``tcp_keepalive_time`` value on all machines
 hosting MongoDB processes. This includes all machines hosting
 :program:`mongos` or :program:`mongod` servers.
 
-Windows users should consider the `Windows Server Technet Article on
-KeepAliveTime configuration
-<http://technet.microsoft.com/en-us/library/dd349797.aspx#BKMK_2>`_
-for more information on setting keep alive for MongoDB deployments on
-Windows systems.
-
 What tools are available for monitoring MongoDB?
 ------------------------------------------------
 

source/includes/fact-tcp-keepalive-linux.rst

@@ -0,0 +1,14 @@
+On Linux systems you can use the following operation to check the
+value of ``tcp_keepalive_time``:
+
+.. code-block:: sh
+
+   cat /proc/sys/net/ipv4/tcp_keepalive_time
+
+The value is measured in seconds. You can change the
+``tcp_keepalive_time`` value with the following operation:
+
+.. code-block:: sh
+
+   echo <value> > /proc/sys/net/ipv4/tcp_keepalive_time
+

source/includes/fact-tcp-keepalive-osx.rst

@@ -0,0 +1,13 @@
+For OS X systems, issue the following command to view the keep alive
+setting:
+
+.. code-block:: sh
+
+   sysctl net.inet.tcp.keepinit
+
+To set a shorter keep alive period use the following invocation:
+
+.. code-block:: sh
+
+   sysctl -w net.inet.tcp.keepinit=<value>
+

source/includes/fact-tcp-keepalive-windows.rst

@@ -0,0 +1,22 @@
+For Windows systems, issue the following command to view the keep alive
+setting:
+
+.. code-block:: powershell
+
+   reg query HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters /v KeepAliveTime
+
+The registry value is not present by default. The system default used
+if the value is absent, is 7200000 *milliseconds*, or ``0x6ddd00`` in
+hexadecimal. To set a shorter keep alive period use the following
+invocation in an Administrator :guilabel:`Command Prompt`, where
+``<value>`` is expressed in hexadecimal (e.g. ``0x0124c0`` is 120000):
+
+.. code-block:: powershell
+
+   reg add HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ /v KeepAliveTime /d <value>
+
+Windows users should consider the `Windows Server Technet Article on
+KeepAliveTime
+<https://technet.microsoft.com/en-us/library/cc957549.aspx>`_
+for more information on setting keep alive for MongoDB deployments on
+Windows systems.

source/includes/fact-tcp-keepalive.rst

@@ -0,0 +1,3 @@
+.. include:: /includes/fact-tcp-keepalive-linux.rst
+.. include:: /includes/fact-tcp-keepalive-osx.rst
+.. include:: /includes/fact-tcp-keepalive-windows.rst