Thank you Sina!

By unsuccessful do you mean that CS allows the operation but it gets
performed unsuccessfully (hypervisor create task fails)? Or does CS just
refuse the operation ?

Regards,
Jordan

On Thu, Mar 30, 2023 at 7:12 PM Sina Kashipazha
<[email protected]> wrote:

> Hey Jordan,
>
> It seems to be a race condition, I ran small scenario which failed. This
> was my setup:
>
> Node:
> Node84: 8GB ram available, 4GB of that allocated to the VM-1
> Node85: 8GB ram, NO VMs.{}
>
>
> The following actions run at the same time using cmk:
>
>
> Deploy 4GB ram on Node84
> Migrate VM-1 from Node84 to Node85
> Deploy 4GB (without specifying the host id)
>
>
> First Round:
> Deploy 4GB ram on Node84 -> Successful
> Migrate VM-1 from Node84 to Node85 -> Migration cancelled because Host
> does not have enough capacity for vm
> Deploy 4GB (without specifying the host id) -> Successful
>
>
> Second Round:
> Deploy 4GB ram on Node84 -> Unsuccessful, unable to create a deployment
> for VM instance
> Migrate VM-1 from Node84 to Node85 -> Successful
> Deploy 4GB (without specifying the host id) -> Successful
>
>
> Third Round:
> Deploy 4GB ram on Node84 -> Successful
> Migrate VM-1 from Node84 to Node85 -> Successful
> Deploy 4GB (without specifying the host id) -> Unsuccessful, unable to
> create a deployment for VM instance
>
>
> Fourth Round:
> Same as first round.
>
> Kind regards,
> Sina
>
> ------- Original Message -------
> On Thursday, March 30th, 2023 at 2:24 PM, jordan j <[email protected]>
> wrote:
>
>
> >
> >
> > Hey everyone,
> >
> > This week we are doing performance tests on the environment and we
> noticed
> > something weird.
> >
> > Setup:
> > - Cloudstack 4.17.2 + XCP-NG advanced network with SG.
> > - zone with 30 XCP hosts (in 30 clusters) each with 100 GB ram and 100
> cores
> > - There is one compute offering with user dispersing planner. The
> offering
> > has a local storage bound (no shared storage on servers) .
> >
> > Using terraform we tried to deploy 60 instances, 49 GB of ram each and 50
> > cores.
> > Some of them were not deployed (about 5).
> > Running the same task again and again eventually makes the failed
> instances
> > be deployed eventually.
> >
> > Wondering why this happens... looking at the logs i found out that the
> VMs
> > fail because of not enough memory on the XCPs. Error comes from XAPI and
> > not from Cloudstack which makes me conclude that Cloudstack allows the
> task
> > but for some reason the scheduler/planner does not compute the memory
> > resource properly. I wonder if there is a race condition problem where 2
> > instances are assigned the same host server and what happens is sa both
> get
> > created there is memory just for one of them.
> >
> > Tried to simulate the issue by simultaneously creating instances from the
> > GUI on a group of 2 servers but it seems GUI-created-instances even if
> > launched together are executed in order so the scheduler detects when
> there
> > is no more RAM and the rest of the processes are stopped.
> >
> > Has anyone experienced such a problem?
> >
> > Regards,
> > Jordan

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