[ubuntu-cloud] A Basic Eucalyptus Network

[Chase Adams]

Neil Soman wrote:
> On Thu, Jun 18, 2009 at 8:03 AM, Chase Adams<chase at curvedinfinity.com> wrote:
>   
>> Hello,
>> I'm new to enterprise level networks, and I'm helping my workplace (a
>> very small company) buy new server equipment. We don't really need a
>> cloud or any system larger than a single server, but some people in the
>> company want something fancy so we look good to potential clients (we
>> sell a web-based service to the government).
>>
>> So, my question is in order to run -- say --- three eucalyptus nodes on
>> a subnet in STATIC mode, what would be the minimum hardware required? In
>> my personal readings, it seems like I'd need the three nodes, the
>> command server, a load balancer, router, and switch. Is that right?
>>
>> If that's right, the part I've never touched is the HTTP load balancer.
>> How does an HTTP request end up getting tossed around through a
>> eucalyptus system? When the VMs boot up, claim a physical network
>> interface, and get assigned an IP, how does the load balancer know? --
>> I'm aware that in STATIC mode letting the load balancer "know" isn't
>> necessary, but it seems strange with DHCP or having multiple eucalyptus
>> users. It makes me believe I'm missing some feature eucalyptus has. --
>> Does the eucalyptus control server forward HTTP requests or something?
>>     
>
> If you have 3 nodes in your setup, you don't need to worry about load
> balancers or anything else. The only point of contact for users and
> user requests is the cloud controller/front end. Communication between
> various components of the system is via standard web services
> security, but global state is maintained at the front end. The user
> doesn't have to worry about individual components and how they
> interact (unless, of course, you are interested in
> developing/extending eucalyptus). You need one cloud controller, one
> cluster controller and one or more nodes. In your setup, you can
> install "eucalyptus-cloud" and "eucalyptus-cc" on a single machine and
> "eucalyptus-nc" on your nodes.
>
> Here is an overview of various networking modes, what features they do
> (or more importantly, do not, provide) and how to set them up.
>
> http://open.eucalyptus.com/wiki/EucalyptusNetworking_v1.5
>
> Hope that helps.
> neil
>   
Thanks for the reply Neil,

So if I install the cloud and cluster controllers on the same computer, 
that server will act as a proxy for http traffic? In other  words, I can 
pretend like the controller is just one big computer? I don't believe 
this is mentioned in the documentation.

On an aside, say my existing web app saves files to the filesystem. Will 
it be necessary to configure Walrus/s3fs for the directories the web app 
uses? If an application does create a new file on one of the VMs (silly 
devs), what behavior will happen? Will the file persist on that 
particular VM but not on other ones? If that VM restarts, will it lose 
the file?

Thanks again,
Chase