(DOCSP-1271, DOCS-10405): Updated Production Notes.

source/administration/production-notes.txt

@@ -559,6 +559,44 @@ possible, use XFS as it generally performs better with MongoDB.
    *on directories*. For example, HGFS and Virtual Box's shared
    folders do *not* support this operation.
 
+Set ``vm.swappiness`` to ``1``
+``````````````````````````````
+
+“Swappiness” is a Linux kernel setting that influences the behavior of
+the Virtual Memory manager when it needs to allocate a swap, ranging
+from ``0`` to ``100``, inclusive. 
+
+- A setting of ``0`` tells the kernel to swap only to avoid
+  out-of-memory problems. 
+
+- A setting of ``100`` tells it to swap aggressively to disk.
+
+If your host runs kernel versions ``3.5`` or later, or 
+:abbr:`RHEL (Red Hat Enterprise Linux)` / CentOS kernel ``2.6.32-303`` 
+or later, setting this value to ``0`` could disable swapping. Set this 
+to ``1``.
+
+To see what the current swappiness level is, run:
+
+.. code-block:: sh
+
+   example@example:$ cat /proc/sys/vm/swappiness
+
+   60
+
+To change swappiness while the system is running, run: 
+
+.. code-block:: sh
+
+   example@example:$ sysctl vm.swappiness=1
+
+To change swappiness permanently, edit the ``/etc/sysctl.conf`` file in
+your preferred text editor and change this value:
+
+.. code-block:: ini
+
+   vm.swappiness = 1
+
 .. _linux-recommended-configuration:
 
 Recommended Configuration
@@ -740,20 +778,52 @@ accommodate Windows' commitment rules during peak database use.
 MongoDB on Virtual Environments
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-This section describes considerations when running MongoDB in some of the
-more common virtual environments.
+This section describes considerations when running MongoDB in some of 
+the more common virtual environments.
 
 For all platforms, consider :ref:`virtualized-disks-scheduling`.
 
-EC2
-```
+:abbr:`AWS (Amazon Web Services)` :abbr:`EC2 (Elastic Compute Cloud)`
+`````````````````````````````````````````````````````````````````````
+
+There are two performance configurations to consider:
+
+- Reproducible performance for performance testing or benchmarking, and
+- Raw maximum performance
+
+To tune performance on :abbr:`EC2 (Elastic Compute Cloud)` for either 
+configuration, you should:
+
+- Enable :abbr:`AWS (Amazon Web Services)`
+  `Enhanced Networking <http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking.html#enabling_enhanced_networking>`_ 
+  for your instance. Not all instance types support Enhanced Networking. 
+
+  To learn more about Enhanced Networking, see to the 
+  `AWS documentation <http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking.html#enabling_enhanced_networking>`_.
+
+If you are concerned more about reproducible performance on 
+:abbr:`EC2 (Elastic Compute Cloud)`, you should also:
+
+- Use provisioned :abbr:`IOPS (Input/Output Operations Per Second)` 
+  for the storage, with separate devices for journal and data. Do not 
+  use the ephemeral (:abbr:`SSD (Solid State Disk)`) storage available 
+  on most instance types as their performance changes moment to moment.
+  (The ``i`` series is a notable exception, but very expensive.)
+
+- Disable :abbr:`DVFS (dynamic voltage and frequency scaling)` and
+  :abbr:`CPU (central processing unit)` power saving modes.
+
+  .. seealso::
+
+     `Amazon documentation on Processor State Control <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/processor_state_control.html>`_
+
+- Disable hyperthreading.
+
+  .. seealso::
+
+     `Amazon blog post on disabling Hyper-Threading <https://aws.amazon.com/blogs/compute/disabling-intel-hyper-threading-technology-on-amazon-linux/>`_.
 
-When available, enable AWS's `Enhanced Networking
-<http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking.html#enabling_enhanced_networking>`_
-for your instance. Not all instance types support Enhanced Networking.
-Refer to the `AWS documentation
-<http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking.html#enabling_enhanced_networking>`_
-for more information.
+- Use ``numactl`` to bind memory locality to a single socket.
 
 .. _windows-azure-production-notes: