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Re: [DISCUSS] deployment planner improvement


I agree, it is affecting all hypervisor... I basically had to migrate a bunch of vm manually to re-balance a cluster after an upgrade or even after re-adding new host to a cluster.

Personally, I think Cloudstack should be able to handles this <auto-re balancing> of resource, example: having a piece of code somewhere that can run every hours or on demand to re-calculate and re-balance resources across hosts within a cluster...

Even the deployment planner is not really relevant here: this process will basically balance new VM creation through different clusters of a POD, not between hosts within a cluster and it's also becoming a nightmare when you start to do cross-cluster migration...

Sum of all : The deployment strategies planner should be re-worked a bit...

+1 on #scoopcreep ;)

Marcus ( mjutras@xxxxxxxxxxxx )

On 2018-09-07 6:01 AM, Paul Angus wrote:
I think that this affects all hypervisors as CloudStack's deployment strategies are generally sub-optimal to say the least.
 From what our devs have told me, a large part of the problem is that capacity/usage and suitability due to tags is calculated by multiple parts of the code independently, there is no central method, which will give a consistent answer.

In Trillian we take a micro-management approach and have a custom module which will return the least used cluster, the least used host or the least used host in a given cluster.  With that info we place VMs on a specific hosts - keeping virtualised hypervisors in the same cluster (least used) so that processor types match, and all other VMs on the least used hosts.

For cross-cluster migrations (VMs and/or storage) I think that most times people want to move from cluster A to the least used (cluster/storage) in cluster B - making them choose which host/pool is actually unhelpful.

#scopecreep - sorry Pierre-Luc

Kind regards,

Paul Angus

paul.angus@xxxxxxxxxxxxx
www.shapeblue.com
Amadeus House, Floral Street, London  WC2E 9DPUK
@shapeblue

-----Original Message-----
From: Will Stevens <wstevens@xxxxxxxxxxxx>
Sent: 06 September 2018 19:45
To: dev@xxxxxxxxxxxxxxxxxxxxx; Marc-Andre Jutras <mjutras@xxxxxxxxxxxx>
Subject: Re: [DISCUSS] deployment planner improvement

If I remember correctly, we see similar issues on VMware.  Marcus, have you seen similar behavior on VMware?  I think I remember us having to manually vMotion a lot of VMs very often...

*Will Stevens*
Chief Technology Officer
c 514.826.0190

<https://goo.gl/NYZ8KK>


On Thu, Sep 6, 2018 at 2:34 PM Pierre-Luc Dion <pdion@xxxxxxxxxxxx> wrote:

Hi,

I'm working with a University in Montreal and we are looking at
working together to improve the deployment planner. Mainly for post
VM.CREATE tasks.
Because  what we observed with cloudstack, in our case with XenServer,
overtime, a cluster will become unbalanced in therm of workload, vm HA
will move VMs all over the the cluster which cause hotspot inside a cluster.
Also, when performing maintenance  xenmotion of VM spread them in the
cluster but does not consider host usage and at the end of a
maintenance it require manual operation to repopulate VMs on the last
host updated.  OS preference not taken into account  except for VM.CREATE.

So,
I'd like to work on improving VMs dispersion during and post outage
and maintenances. when a cluster resources are added or removed.

Would you have any more requirement, we will document a feature spec
in the wiki which I believe it's still a requirement ?

Does using KVM have similar issues over time?

I don't think it would make sense to cloudstack to automatically take
decision on moving VMs but for now create report of recommended action
to do and provide steps to do them. tbd.

Cheers,

PL