[pve-devel] adding a vm workload scheduler feature

[Alexandre DERUMIER]

>>I assume it is hard to get this stable (just a feeling). 
yes, same for me.

>>On the other side, this would be simple 
>>to implement. Each node is responsible to move its own VMs, so you do not even 
>>need a lock. 
I was more thinking about a lock, to avoid node2 migrate vm to node1, when node1 try to migrate a vm to node3 for example.


>>My plan was to integrate this into the HA manager, but then you only have the 
>>feature for HA enabled VMs. 

Could be great to have it without HA too.


>>But the CRM code shows how to use a cluster wide lock to implement a 'master' 
>>role. 
Ok,thanks, I'll try to have a look at it.


Don't have time for now, but I'll begin to do test in January.



----- Mail original -----
De: "dietmar" <dietmar at proxmox.com>
À: "aderumier" <aderumier at odiso.com>, "pve-devel" <pve-devel at pve.proxmox.com>
Envoyé: Mardi 17 Novembre 2015 08:40:19
Objet: Re: [pve-devel] adding a vm workload scheduler feature

> What do you think about it ? 

interesting 

> 
> As we don't have master node, I don't known how to implement this: 
> 
> 1) each node try to migrate his own vms to another node with less cpu usage. 
> maybe with a global cluster lock to not have 2 nodes migrating in both way 
> at the same time ? 

I assume it is hard to get this stable (just a feeling). On the other side, this 
would be simple 
to implement. Each node is responsible to move its own VMs, so you do not even 
need a lock. 

> 2) have some kind of master service in the cluster (maybe with corosync 
> service ?), 
> which read global stats of all nodes, and through an algorithm, do the 
> migrations. 
> 
> Don't known which way is better ? 

My plan was to integrate this into the HA manager, but then you only have the 
feature 
for HA enabled VMs. 

But the CRM code shows how to use a cluster wide lock to implement a 'master' 
role.