![Doug Hellmann](/assets/img/avatar_default.png)
Change-Id: I39cabc18e40eee968309b63de3d74e3e828645d9 Signed-off-by: Doug Hellmann <doug@doughellmann.com>
62 lines
2.5 KiB
ReStructuredText
62 lines
2.5 KiB
ReStructuredText
=============================================
|
|
Hardware considerations for high availability
|
|
=============================================
|
|
|
|
When you use high availability, consider the hardware requirements needed
|
|
for your application.
|
|
|
|
Hardware setup
|
|
~~~~~~~~~~~~~~
|
|
|
|
The following are the standard hardware requirements:
|
|
|
|
- Provider networks: See the *Overview -> Networking Option 1: Provider
|
|
networks* section of the
|
|
`Install Tutorials and Guides <https://docs.openstack.org/ocata/install>`_
|
|
depending on your distribution.
|
|
- Self-service networks: See the *Overview -> Networking Option 2:
|
|
Self-service networks* section of the
|
|
`Install Tutorials and Guides <https://docs.openstack.org/ocata/install>`_
|
|
depending on your distribution.
|
|
|
|
OpenStack does not require a significant amount of resources and the following
|
|
minimum requirements should support a proof-of-concept high availability
|
|
environment with core services and several instances:
|
|
|
|
+-------------------+------------------+----------+-----------+------+
|
|
| Node type | Processor Cores | Memory | Storage | NIC |
|
|
+===================+==================+==========+===========+======+
|
|
| controller node | 4 | 12 GB | 120 GB | 2 |
|
|
+-------------------+------------------+----------+-----------+------+
|
|
| compute node | 8+ | 12+ GB | 120+ GB | 2 |
|
|
+-------------------+------------------+----------+-----------+------+
|
|
|
|
We recommended that the maximum latency between any two controller
|
|
nodes is 2 milliseconds. Although the cluster software can be tuned to
|
|
operate at higher latencies, some vendors insist on this value before
|
|
agreeing to support the installation.
|
|
|
|
You can use the `ping` command to find the latency between two servers.
|
|
|
|
Virtualized hardware
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
For demonstrations and studying, you can set up a test environment on virtual
|
|
machines (VMs). This has the following benefits:
|
|
|
|
- One physical server can support multiple nodes,
|
|
each of which supports almost any number of network interfaces.
|
|
|
|
- You can take periodic snap shots throughout the installation process
|
|
and roll back to a working configuration in the event of a problem.
|
|
|
|
However, running an OpenStack environment on VMs degrades the performance of
|
|
your instances, particularly if your hypervisor or processor lacks
|
|
support for hardware acceleration of nested VMs.
|
|
|
|
.. note::
|
|
|
|
When installing highly available OpenStack on VMs,
|
|
be sure that your hypervisor permits promiscuous mode
|
|
and disables MAC address filtering on the external network.
|