Open Stack

Yes, thats also an option. But we would like to get the flexibility and
features that a floating IP provides.

So, in that case, there wont be any floating IPs , openstack will assign
public IPs like it assigning private IPs , right?

On Tue, Apr 26, 2016 at 12:57 PM, gustavo panizzo (gfa) <gfa at zumbi.com.ar>
wrote:

> On Tue, Apr 26, 2016 at 12:03:03PM +0530, Jaison Peter wrote:
> > Hi all,
> >
> > I  was working in an openstack project to build a small to medium level
> > public cloud on the top of openstack. We are researching lot more about
> > scalable large openstack deployments and planning our design accordingly.
> > Initially we will be having 50+ compute nodes and planning to grow up to
> > 200 compute nodes in an year by migrating the existing clients to new
> > platform.
> >
> > I have many concerns about the scaling and right choices , since
> openstack
> > is offering lot of choices and flexibility, especially in networking
> > side.Our major challenge was choosing between simplicity and performance
> > offered by Linux bridge and features and DVR offered by OVS.  We decided
> to
> > go with OVS, though some were suggesting like OVS is slow in large
> > deployments. But the distributed L3 agents and bandwidth offered by DVR
> > inclined us towards OVS. Is it a better decision?
> >
> > But one of the major drawback we are seeing with DVR is the public IP
> > consumption. If we have 100 clients and 1 VM per client , eventually
> there
> > will be 100 tenants and 100 routers. Since its a public cloud, we have to
> > offer public IP for each VM. In DVR mode, fip name space in compute will
> be
> > consuming one public IP and if 100 VMs are running among 20 computes,
> then
> > total 20 public IPs will be used among computes. And a router SNAT name
> > space will be created for each tenant router(Total 100)  and each of it
> > will be consuming 1 public  IP and so total 100 public IPs will be
> consumed
> > by central SNAT name spaces. So total 100 + 20 = 120 public IPs will be
> > used by openstack components and  100 will be used as floating IPs (1:1
> > NAT) by VMs. So we need 220 public IPs for providing dedicated public IPs
> > for 100 VMs !! Anything wrong with our calculation?
> >
> > From our point of  view 120 IPs used by openstack components in our case
> > (providing 1:1 NAT for every VM) is wastage of IPs and no any role in
> > network traffic. Centrallized SNAT is useful , if the client is opting
> for
> > VPC like in AWS and he is not attaching floating IPs to all instances in
> > his VPC.
> >
> > So is there any option while creating DVR router to avoid creating
> central
> > SNAT name space in controller node ? So that we can save 100 public IPs
> in
> > the above scenario.
>
> I've never used DVR, so I won't speak about it but I've run private
> clouds without wasting public ip address using provider networks.
>
> most of VM's had a single vNIC attached to a private network, shared or
> private to the tenant, optionally a VM may had a second vNIC attached to
> a public shared network.
>
> first i wanted to avoid the network node as it was a SPF, also it
> limits the bandwidth available to VM, also it allowed us to use our
> existing, proven, networking gear.
>
> my 0.02$
>
>
>
> --
> 1AE0 322E B8F7 4717 BDEA BF1D 44BB 1BA7 9F6C 6333
>
> keybase: http://keybase.io/gfa
>
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