cloudstack-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Alex Ough <alex.o...@sungard.com>
Subject Re: A question on vm migrations when hosts are set into a maintenance mode.
Date Wed, 13 Nov 2013 17:39:17 GMT
It sounds a little scary...

I looked at the history and found these.

8/9/ : file moved to engine by Alex Huang
9/16 : '_mgmtServer.getExecuteInSequence()' changed to
'getExecuteInSequence()' by Alex Huang


Hi Alex Huang,
I'm not sure if you're aware of this, but can you check this for me?

Thanks
Alex Ough



On Wed, Nov 13, 2013 at 11:18 AM, Marcus Sorensen <shadowsor@gmail.com>wrote:

> I'm not sure. I know in the past when I've seen files change locations
> it has also clobbered updates to that file. Someone branched, did the
> reorganization work, and merged, while in-between the original file
> changed.
>
> On Wed, Nov 13, 2013 at 9:21 AM, Alex Ough <alex.ough@sungard.com> wrote:
> > All,
> >
> > While merging my changes to 4.3 branch, I found that the option,
> > 'execute.in.sequence.hypervisor.commands' is NOT used in Start/Stop/Copy
> > commands in 'VirtualMachineManagerImpl.java' any more as below.
> >
> >
> > *StopCommand stop = new StopCommand(vm, getExecuteInSequence());*
> >
> > *protected boolean getExecuteInSequence() {*
> > *     return false;*
> > *}*
> >
> > As you see in the above, the function, 'getExecuteInSequence', just
> returns
> > false instead of getting the value from the global variable.
> >
> > And one more change is that the file has been moved to
> > 'engine/orchestration/src/com/cloud/vm' from 'server/src/com/cloud/vm'.
> >
> > Am I missing something related with this or do we stop supporting this
> > option in 4.3?
> > I'm a little confused, so please help me resolve this.
> >
> > Thanks
> > Alex Ough
> >
> >
> >
> >
> > On Tue, Nov 12, 2013 at 4:20 PM, Alex Ough <alex.ough@sungard.com>
> wrote:
> >
> >> Thanks a lot for your confirmation, Marcus.
> >> I'll create a review request unless anyone has an objection.
> >>
> >> Thanks
> >> Alex Ough
> >>
> >>
> >> On Tue, Nov 12, 2013 at 3:37 PM, Marcus Sorensen <shadowsor@gmail.com
> >wrote:
> >>
> >>>  I have done parallel KVM migrations without issue, it's "supposed to
> >>> work". Really I think it's in the same boat as parallel start/stop. It
> >>> should work, but the config option is there just in case. I think we
> >>> should add it.
> >>>
> >>> On Thu, Oct 3, 2013 at 11:41 AM, Chip Childers
> >>> <chip.childers@sungard.com> wrote:
> >>> > On Thu, Oct 03, 2013 at 11:44:46AM -0500, Alex Ough wrote:
> >>> >> I'm not sure what else commands 'MigrateCommand' actually execute
in
> >>> >> addition to 'Start/Stop/CopyCommand', but can we include
> >>> 'MigrateCommand'
> >>> >> if it consists of only those 3 commands?
> >>> >>
> >>> >> Thanks
> >>> >> Alex Ough
> >>> >
> >>> > In the case of VMware, the migrate command is executed via the
> >>> > MigrateVMTask that's part of the VMware SDK (see
> >>> >
> vmware-base/src/com/cloud/hypervisor/vmware/mo/VirtualMachineMO.java).
> >>> >
> >>> > For VMware, I know that vCenter will queue and process concurrent
> >>> > requests for migrations.  Specifically, it will throttle the
> migrations
> >>> > happening, based on it's internal concurrency constraints, but the
> task
> >>> > queue will still accept more connections.  Obviously the risk are the
> >>> > VMware layer tasks timing out if it takes too long for the task
> queue to
> >>> > complete.
> >>> >
> >>> > As for XenServer, it's happening in what appears to be a similar way
> >>> > (although the source host is the target for the migration API call).
> >>> >
> >>> > Check
> >>> >
> >>>
> plugins/hypervisors/xen/src/com/cloud/hypervisor/xen/resource/CitrixResourceBase.java.
> >>> >
> >>> > I'm not familiar enough with XenServer's concurrency model for
> >>> > migrations.  Any experts know the answer to if it can handle
> concurrency
> >>> > in a stable way?
> >>> >
> >>> > With KVM, it's obviously executing via the agent.  Similarly to
> >>> > XenServer, I'm not familiar enough to know about concurrent
> operations.
> >>> >
> >>> > So do the HV experts on the list have any opinions about XenServer
> and
> >>> > KVM migration concurrency?
> >>> >
> >>> > -chip
> >>> >
> >>> >
> >>>
> >>>
> >>
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message