Skip to content

(DOCSP-1271, DOCS-10405): Updated Production Notes. #3233

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Mar 5, 2018
Merged

(DOCSP-1271, DOCS-10405): Updated Production Notes. #3233

Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
e068d58
(DOCSP-1271, DOCS-10405): Updated Production Notes.
Feb 14, 2018
bfe8d1f
Updated per @dalyd and @steveren reviews.
Feb 21, 2018
58d1cb8
Updated per @dalyd review.
Mar 5, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
73 changes: 63 additions & 10 deletions source/administration/production-notes.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -559,6 +559,43 @@ 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`` at least ``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 ``2.6.32-303``
or later, setting this value to ``0`` could disable swapping. Set this
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't understand this qualification. Why not just say "kernel version 2.6.32-303 or later"? Are there some versions between 2.6.32-303 and 3.5 to which this doesn't apply?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I clarified.

to ``1``.
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The section title says "at least 1", so maybe we should say that here as well.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Fixed.


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
Expand Down Expand Up @@ -740,20 +777,36 @@ 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)`
`````````````````````````````````````````````````````````````````````

- When available, 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>`_.

- Use provisioned IOPS for the storage, with separate devices for
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

As long as you're using the :abbr: directive for other abbreviations around here, might as well add it for IOPS too.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Fixed.

journal and data. Do not use the ephemeral storage available on some
instance types as their performance changes moment to moment.

- Disable hyperthreading,
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The suggestions coming from the perf team here are specifically aimed at recommendations for getting reproducible performance tests. They are not aimed at getting maximum performance. As such, they aren't for every body. If a user cares about consistency of performance over raw performance (for benchmarking, or just predictability), they should do this. If they care about performance more than performance reproducibility, they should not pin to one socket and should not disable hyperthreading.

To some extents that applies to the ephemeral storage too. I don't know if ephemeral storage is better or worse for someone just concerned about performance, but if someone is wants reproducibility they should use the provisioned IOPS.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I clarified this.

:abbr:`DVFS (dynamic voltage and frequency scaling)`,
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Are you using the DVFS abbreviation somewhere?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It is staged here. I was looking for "frequency scaling" and only came across this explanation, which was in sync with what was discussed. Did I miss something?

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The staging view helped. I see now.

Do you want more details on some of these. There are linux command line options for some of the stuff, although they are on the default linux ami now. We have notes on the DVFS stuff also.

For c states the linux boot option is processor.max_cstate=1 or sometimes intel_idle.max_cstate=1 depending on kernel version. I found this in my notes which helped me at the time:
https://gist.github.com/wmealing/2dd2b543c4d3cff6cab7 and https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/processor_state_control.html
We tested with c3 and c4 instances. The c and p state controls only worked on the c4 generation, but the c3 ended up being lower noise.

There's also an idle=poll setting to similar effect. That is baked into the basic ami image now and we're using it.

:abbr:`CPU (central processing unit)` power saving modes.

.. seealso::

- `Amazon blog post on disabling Hyper-Threading <https://aws.amazon.com/blogs/compute/disabling-intel-hyper-threading-technology-on-amazon-linux/>`_.

- `Amazon documentation on Processor State Control <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/processor_state_control.html>`_

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:

Expand Down