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Configuring Multi-Host High Availability

asked 2013-06-03 03:57:52 -0500

henrik16 gravatar image

updated 2013-06-11 13:14:02 -0500

smaffulli gravatar image

I would like to have my compute nodes with Public IP address access replacing the network node ... I can find this in this guide but I can't understand what I really need to do... note that I only want to do the HA Option 1: Multi-host to eliminate the network host as a single point of failure.

I have installed the services in my two compute nodes and have the eth0 with a public IP but I can't understand the part of the bridge (br100). I can't understand how to configure my /etc/network/interfaces file because in my course I haven't study that in depth.

Can anyone explain me and give me tips to configure this right? Note that I only want to configure the HA for network... and note too that I have already Installed the services on both compute nodes and Configured the eth0 with a public IP

Now I need to setup the br100 but I can't understand how to do that. Is there a step-by-step guide I can read?

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Here's some information about Linux network bridging.

annegentle gravatar imageannegentle ( 2013-06-11 09:56:57 -0500 )edit

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answered 2013-06-03 09:38:36 -0500

annegentle gravatar image

updated 2013-06-05 07:48:57 -0500

I'll try to address multiple questions: What do I need ? Each of your compute nodes needs to run the services listed on that page, nova-compute, nova-network, and nova-api-metadata or nova-api, depending on whether you want each compute node to accept API requests. You must set multi_host to true in nova.conf and when creating networks.

Is that correct to grizzly version? I believe the page is still correct for Grizzly.

Can I give up of network node when finish? Yes, you are distributing the network work after doing the Option 1 on that page. You are running nova-network rather than any quantum services for Networking.

How can I see if my compute host is an endpoint? I don't think you'd configure Identity to list each compute node as an API endpoint. I think you'd configure your cloud controller to be the API endpoint, and the multi host option ensures the requests are distributed.

What are API requests? Each OpenStack service provides a REST API. The API requests in this case are for creating a new server for example, or for any number of actions you can request to change the state of a server.

But my eth1 should have a bridge and also two ip addresses? I can't understand the meaning of fixedrange in that guide. Fixedrange is a CIDR notation range of IP addresses assigned automatically to each compute node. Hence in the diagram you see the IP addresses being allocated from that designated subnet.

In Flat Mode, a network administrator specifies a subnet. The IP addresses for VM instances are grabbed from the subnet, and then injected into the image on launch. Each instance receives a fixed IP address from the pool of available addresses. A system administrator may create the Linux networking bridge (typically named br100, although this configurable) on the systems running the nova-network service. All instances of the system are attached to the same bridge, configured manually by the network administrator.

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Hi annegentle and thank you for your answer ! So what are API requests? For what reason should I accept or not accept them? I think you answer all my questions!

henrik16 gravatar imagehenrik16 ( 2013-06-04 03:40:57 -0500 )edit

I can't understand when I need to create and change my network interfaces... So I have eth0 with public address ok. But my eth1 should have a bridge and also two ip addresses? I can't understand the meaning of fixed_range in that guide because in the diagram it has and below it has

henrik16 gravatar imagehenrik16 ( 2013-06-04 04:27:28 -0500 )edit ... help :( I'm really noob in this ...

henrik16 gravatar imagehenrik16 ( 2013-06-04 04:27:46 -0500 )edit

Pretty sure I can't help you further as I'm not a network admin. :) But hopefully you can get further along in your understanding. I'd also recommend reading

annegentle gravatar imageannegentle ( 2013-06-05 07:49:51 -0500 )edit

I have updated my question and now I think that is more explicity and completly... so now if anyone can help me I will be thankful !

henrik16 gravatar imagehenrik16 ( 2013-06-11 09:26:13 -0500 )edit

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Asked: 2013-06-03 03:57:52 -0500

Seen: 520 times

Last updated: Jun 11 '13