[pve-devel] Pve Load Balance...

[Thomas Lamprecht]

Hi,

On 03/01/2017 10:55 PM, Andreas Steinel wrote:
> Hi Gilberto,
>
> ah yes, now it's clear.
>
> Yes, this would be a good thing, but it is very hard to do that in
> terms of "finding a metric". There is memory pressure, cpu load and
> possible local storage (for non-shared-storage migrations), but should
> be doable. I think you can file a feature request to get this
> implemented.

It is somewhat on our radar, but yes as you said the metric finding is a 
problem which could be not  easy to get right.
We thought about starting with static loads manually assigned to each 
VM/CT, and a capacity for the hosts, this would balance the load of to 
get started VMs over the cluster.

If this will get advanced I'd add some dynamic metric aggregation.
For the metrics, I'd say CPU and Memory and eventually Network load 
could be possible inputs in our control loop.
The main problems/pitfalls would be:
* the cluster acts as a non linear system, not the easiest to control 
(automatically) :)
* never ever update control loop faster than your systems (cluster, or 
local nodes) sample and delay time
   (Totzeit, in German not sure if I got  the correct translation), this 
would just make the system unstable sooner or later.
* the worst case delay time would be (highly) probably the one of a 
migration, during that time we may even generate more load (i.e. on a 
network metric) dependent of the cluster/node setup
* as our delay time is quite huge we need to look at reducing 
oscillation, it should be nonexistent.
* the very very different setups in which Proxmox VE gets deployed

So as a result of this local storage is not an ideal metric, imo.
It act as an PT2 element so we increase delay time further (we need to 
read and copy all disks), a better solution for this is to move this 
property to storage technology, i.e. use Ceph, Sheepdog, GlusterFS, etc..

Anyway, nothing fixed planned, I thought just a little about it and we 
consider it in general.

cheers,
Thomas

>
> Best
> Andreas
>
> On Wed, Mar 1, 2017 at 10:35 PM, Gilberto Nunes
> <gilberto.nunes32 at gmail.com> wrote:
>> Hello Andreas...
>>
>> Perhaps I don't make myself clear...
>>
>> With Load Balance I mean when in a node cluster there is a high load, a VM
>> could to automatic migrated to other node with less load... Something like
>> that...
>> Sorry if I messed up the concepts...
>> Perhaps you can enlight me.
>>
>> Regards
>>
>> 2017-03-01 18:25 GMT-03:00 Andreas Steinel <a.steinel at gmail.com>:
>>
>>> Hi Gilberto,
>>>
>>> What do you want to load balance? PVE is a IaaS architecture and
>>> normally you would implement balancing on a SaaS architecture, so one
>>> layer higher (towards the application).
>>>
>>> Best,
>>> Andreas
>>>
>>> On Wed, Mar 1, 2017 at 12:31 PM, Gilberto Nunes
>>> <gilberto.nunes32 at gmail.com> wrote:
>>>> Hello friends
>>>>
>>>> Is there any plan to implement Load Balance in next releases of Proxmox
>>> VE??
>>>> I think this is could be a nice feature to add in main stream version....
>>>>
>>>> What about?
>>>>
>>>> --
>>>> Obrigado
>>>>
>>>> Cordialmente
>>>>
>>>>
>>>> Gilberto Ferreira
>>>>
>>>> Consultoria em Servidores e Serviços Linux | Virtualização Proxmox |
>>>> Zentyal Server | Zimbra Mail Server
>>>>
>>>> (47) 3025-5907
>>>> (47) 99676-7530
>>>>
>>>> Skype: konnectati
>>>>
>>>>
>>>> www.konnectati.com.br
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>>
>>
>> --
>> Obrigado
>>
>> Cordialmente
>>
>>
>> Gilberto Ferreira
>>
>> Consultoria em Servidores e Serviços Linux | Virtualização Proxmox |
>> Zentyal Server | Zimbra Mail Server
>>
>> (47) 3025-5907
>> (47) 99676-7530
>>
>> Skype: konnectati
>>
>>
>> www.konnectati.com.br
>> _______________________________________________
>> pve-devel mailing list
>> pve-devel at pve.proxmox.com
>> http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
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