Why install compute nodes and controllers on different machines?

asked 2015-07-20 19:06:10 -0600

anonymous user


updated 2015-07-21 02:48:53 -0600

Is there any official documentation justifying the installation of compute nodes and controllers on separate machines?

Why in production environments it is recommended to dedicate machines to each service? I found some documentation of hardware vendors that recommends three of each type of node (controller/network, compute and storage), but they do not clearly justify that decision.

Thank you for your time.

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answered 2015-07-21 02:58:54 -0600

updated 2015-07-23 08:20:30 -0600

In production, you are likely to want / need different kind of hardware for the different nodes:

  • For controller : IO + CPU + Network
  • For network : Network + some CPU
  • For compute : CPU + RAM (eventually some GPUs too)

Besides that you may also want some kind of redundancy for the critical nodes / services, and you may want to have a lot of compute nodes or scaling the quantity of those. The CPUs on your compute nodes are the really interesting ones, you may want to have some ARM or PowerPC VMs running. It's there that the CPU's hardware virtualization features will be needed, so you'll want the youngest generation for those nodes.

You'll have different quantities of administration work to do on the different kind of nodes, backup for example, should not even be needed for the compute nodes, because they should already be easily / automatically (re-)constructed through automation (puppet, chef, salt...), etc...

All of those may be reasons to do it the way it is documented.

It all depends on what exactly you mean by production. If you want to have a few virtualized internal services, or run a full datacenter of computationally intensive science research projects, provide on-demand WEB servers, etc...

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Asked: 2015-07-20 19:06:10 -0600

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Last updated: Jul 23 '15