[PLUG] help with /proc/cpuinfo

[VY]

Hi Aaron

Thanks for confirming.  I do not yet know how to troubleshoot in a Xen env
but now that you
dissected the data with me (which no one on our team has so far), I
understand the situation now.

There's no much I can do, and we do not have another place to migrate this
image.
Oh well....

thanks again!

-v


On Thu, Apr 25, 2019 at 1:05 PM Aaron Burt <aaron at bavariati.org> wrote:

> On 2019-04-25 10:54, VY wrote:
> > Yes, I love to learn as well.
> >
> > This is the output to lscpu:
> >   Architecture:          x86_64
> [...]
> > Hypervisor vendor:     Xen
> > Virtualization type:   full
>
> Ah-hah.  You're in a VM, and I'll bet you have a "noisy neighbor."
>
> > The load average is:
> > load average: 464.68, 415.14, 416.96
> > which does not make sense at all.
>
> Loadavg is just how many processes are waiting to use the CPU.
>
> > The rest of TOP:
> >   Cpu(s): 51.3%us, 16.0%sy,  0.0%ni, 32.0%id,  0.0%wa,  0.0%hi,
> > 0.4%si,
> > 0.2%st
> >
> > If I hit 1, it affects all 4 CPUs.
>
> All good.  Very much looks like a "noisy neighbor" problem, which is
> when another VM on the hypervisor is hogging all the CPU (or RAM) and
> leaving you with no compute resources.  From your VM's perspective, it's
> going at the rated clock speed, but time is going by REALLY FAST.
>
> > Can you elaborate on why
> >  >    apicid : 25
> >>   initial apicid : 25
> >
> > 25 is a weird number?   From an earlier thread, is this simply a
> > logical
> > ID?
>
> Eh, sort of.  There should only be a couple APICs in the system.  And
> usually it'll be pretty consistent.
>   But since it's a VM all bets are off.
>
> > All the other systems are reporting this number as 4 and all of them
> > are
> > having reasonable load.
>
> They're on a different hypervisor machine, and probably a different
> version of the hypervisor software.
>
> > I do not have root access nor sudo.  I want to try and find out why
> > the load is so high before I escalate and argue for more privilege.
> > When I brought this up to the responsible team, I was given a probable
> > cause -- There are other activities hosting this VM server and they are
> > causing this issue.
>
> So they already told you that you have a noisy neighbor.  All right
> then.  Don't use that VM and get by on the 3 you have, or ask the team
> to migrate your slow VM to a different hypervisor machine, or ask for a
> new VM on a less loaded hypervisor machine.  But unless the noisy
> neighbor calms down it sounds like your one sad VM isn't getting any
> better.
>
> Is this a customer-facing service?  If so, you should point this out to
> your hosting team.
>
> Good luck,
>    Aaron
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