f6451c96b1
Cleaning up the ha-guide for minor errors and restructure of content. Some bugs have been filed to draw attention to the TODOs inline. Change-Id: Id6cdff494db905826ae87be3e38d587e9829d6da
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2.6 KiB
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62 lines
2.6 KiB
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=============================================
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Hardware considerations for high availability
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=============================================
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When you use high availability, consider the hardware requirements needed
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for your application.
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Hardware setup
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~~~~~~~~~~~~~~
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The following are the standard hardware requirements:
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- Provider networks: See the *Overview -> Networking Option 1: Provider
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networks* section of the
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`Install Tutorials and Guides <http://docs.openstack.org/project-install-guide/newton>`_
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depending on your distribution.
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- Self-service networks: See the *Overview -> Networking Option 2:
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Self-service networks* section of the
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`Install Tutorials and Guides <http://docs.openstack.org/project-install-guide/newton>`_
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depending on your distribution.
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OpenStack does not require a significant amount of resources and the following
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minimum requirements should support a proof-of-concept high availability
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environment with core services and several instances:
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+-------------------+------------------+----------+-----------+------+
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| Node type | Processor Cores | Memory | Storage | NIC |
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+===================+==================+==========+===========+======+
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| controller node | 4 | 12 GB | 120 GB | 2 |
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+-------------------+------------------+----------+-----------+------+
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| compute node | 8+ | 12+ GB | 120+ GB | 2 |
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+-------------------+------------------+----------+-----------+------+
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We recommended that the maximum latency between any two controller
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nodes is 2 milliseconds. Although the cluster software can be tuned to
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operate at higher latencies, some vendors insist on this value before
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agreeing to support the installation.
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You can use the `ping` command to find the latency between two servers.
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Virtualized hardware
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~~~~~~~~~~~~~~~~~~~~
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For demonstrations and studying, you can set up a test environment on virtual
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machines (VMs). This has the following benefits:
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- One physical server can support multiple nodes,
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each of which supports almost any number of network interfaces.
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- You can take periodic snap shots throughout the installation process
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and roll back to a working configuration in the event of a problem.
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However, running an OpenStack environment on VMs degrades the performance of
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your instances, particularly if your hypervisor or processor lacks
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support for hardware acceleration of nested VMs.
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.. note::
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When installing highly available OpenStack on VMs,
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be sure that your hypervisor permits promiscuous mode
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and disables MAC address filtering on the external network.
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