Hi Kelven, > 2) Serialize VM operations > Currently, state transition handling always happens at in-place context, for > example, when management server receives hypervisor VM state report, the > handling of the report is processed within the context, even if there may be > another thread that is handling user request on the same VM. Although we try > to coordinate by checking the state of the VM, by simplify failing it with > concurrent-access exception. > In the new design, we will try to serialize activities to the same VM through > job facility, since there always be one active operation is in executing, the > state transition logic can be simplified. Take the VM migrating case, as it > involves with two hosts, in previous model, with VM state report from > different hosts, we have to handle it carefully as the host report may come > at un-predicted order.
It is my understanding that by serializing the operations - we fix the issue with concurrent tasks for the same object. How would this affect the end user performance, assuming 10 users execute 10 tasks on 10 different VMs, would they all go in the queue and wait for their turn? Thanks ilya > -----Original Message----- > From: Kelven Yang [mailto:kelven.y...@citrix.com] > Sent: Friday, May 03, 2013 10:37 PM > To: dev@cloudstack.apache.org > Subject: [PROPOSAL] VMSync improvement to better co-operate with > external managers for features like HA/DRS and FT > > I would like to propose an improvement effort on VMSync. This is to help > build better interaction with external virtualization manager (i.e., vCenter) > for features like native HA, DRS and FT. > > https://cwiki.apache.org/confluence/display/CLOUDSTACK/FS+- > +VMSync+improvement > > Since it is a low-level change and hard to describe it in short, only > high-level > principals are detailed in FS. > > Please review the first draft of FS and provide your comments and feedback. > > Kelven
