John No need for apologies, if we are all in agreement, should I create feature request and issue tracker?
Thanks ilya > -----Original Message----- > From: John Burwell [mailto:jburw...@basho.com] > Sent: Thursday, May 30, 2013 2:42 PM > To: dev@cloudstack.apache.org > Subject: Re: [DISCUSS] How to best do time sync. (WAS: [VOTE] Release > Apache CloudStack 4.1.0 (fifth round)) > > Ilya and Chip, > > I stand duly corrected. Sorry for diverting the conversation. > > -John > > On May 30, 2013, at 2:22 PM, "Musayev, Ilya" <imusa...@webmd.net> > wrote: > > > I forgot to mention, with option 1, you should have the least issues > > regardless of what hypervisor technology you use - even if you go with > > HyperV :) > > > > And I think Chiradeep is right, it should be Zone based, since this is when > SSVM and CPVM gets created. > > > >> -----Original Message----- > >> From: Musayev, Ilya [mailto:imusa...@webmd.net] > >> Sent: Thursday, May 30, 2013 2:14 PM > >> To: dev@cloudstack.apache.org > >> Subject: RE: [DISCUSS] How to best do time sync. (WAS: [VOTE] Release > >> Apache CloudStack 4.1.0 (fifth round)) > >> > >> John, > >> > >> For vmware, you have 2 options, clock sync will work with native NTP > >> daemon using local ntp servers in your datacenter or use vmware tools > >> native time keeping technique. > >> > >> We have over 2500 VMs, and while we have vmware tools installed on > >> all vms, we choose to use native linux NTPD for time sync VS vmware > >> hypervisor provided time sync. In past, vmware tools time sync was > >> buggy and not recommended, so we decided to keep it simple and make > >> use of existing ntp servers. As of now, inherent issues maybe, if you > >> go through major upgrade of Vsphere, if you change vmware hardware > >> version, if you don't update the tools - you have 3 places where time > >> keeping may break (though I hope vmware dev team consider all that - > >> it is still a possibility) > >> > >> I propose we make this optional when cluster is configured. > >> > >> For example, we have a check box that says > >> 1) use local NTP servers for time keeping (if selected) > >> NTP SERVER1 > >> NTP SERVER2 > >> 2) use native hypervisor vm tools for time sync (be it vmware,kvm, > >> xen or whatever else it may be) > >> > >> We let user make his own decision on how to go about this issue, and > >> user would know best what's applicable for his environment VS us, > >> making decisions on their behalf. > >> > >> For vmware, we have have to submit 3 more arguments into "vm.details" > >> attribute with an option for timesync=vmtools ot timesync=ntp > >> If timesync=ntp, get values of ntpserver1 and ntpserver2, > >> configure local ntp.conf file to use with native linux ntpd daemon > >> If timesync=tools, use vm tools provided time keeping technique > >> > >> Feedback is welcome, > >> > >> Thanks > >> -ilya > >> > >> > >>> -----Original Message----- > >>> From: John Burwell [mailto:jburw...@basho.com] > >>> Sent: Thursday, May 30, 2013 1:44 PM > >>> To: dev@cloudstack.apache.org > >>> Subject: Re: [DISCUSS] How to best do time sync. (WAS: [VOTE] > >>> Release Apache CloudStack 4.1.0 (fifth round)) > >>> > >>> IIya, > >>> > >>> I can't speak to KVM, but on VMWare, clock sync won't work without > tools. > >>> It's not an option. > >>> > >>> Thanks, > >>> -John > >>> > >>> > >>> On Thu, May 30, 2013 at 1:30 PM, Musayev, Ilya > <imusa...@webmd.net> > >>> wrote: > >>> > >>>> I'd say Cluster setting. > >>>> > >>>> We should let users pick if they want to use hypervisor tools based > >>>> sync or local/external NTP servers. > >>>> > >>>> I'm all for local/external NTP servers, as I know how those never > >>>> gave me issues in past (especially when you go through hypervisors > >>>> upgrades and vm tools upgrades). > >>>> > >>>> > >>>> > >>>>> -----Original Message----- > >>>>> From: John Burwell [mailto:jburw...@basho.com] > >>>>> Sent: Thursday, May 30, 2013 1:02 PM > >>>>> To: dev@cloudstack.apache.org > >>>>> Subject: Re: [DISCUSS] How to best do time sync. (WAS: [VOTE] > >>>>> Release Apache CloudStack 4.1.0 (fifth round)) > >>>>> > >>>>> Ilya, > >>>>> > >>>>> One very important note is that NTP is only used for Xen. For KVM > >>>>> and VMWare, time sync is accomplished through kernel > >>>>> drivers/system daemons with NTP configured in the hypervisor > >> configuration. > >>>>> Therefore, this > >>>> model > >>>>> would need to be conditional based on the hypervisor type -- > >>>>> possibly a cluster-level setting? > >>>>> > >>>>> Thanks, > >>>>> -John > >>>>> > >>>>> On May 30, 2013, at 12:58 PM, "Musayev, Ilya" > >> <imusa...@webmd.net> > >>>>> wrote: > >>>>> > >>>>>> Thanks Chip. > >>>>>> > >>>>>> I've posted this response under CLOUDSTACK-2492.. curious what > >>>>>> others > >>>>> may think about a long term solution to this problem.. > >>>>>> > >>>>>> -------------- > >>>>>> I think we should make the whole NTP schema more modular and > >>> robust. > >>>>>> > >>>>>> For example, in my experience working for several companies, not > >>>>>> even once have we used vmware tools time sync - due to known > bugs > >>>>>> and issues. Instead we would prefer to use local NTP server or > >>>>>> external pool.ntp.org > >>>>>> > >>>>>> There are two way we can address this: > >>>>>> > >>>>>> Quick solution (quick means not ideal): > >>>>>> Capture the NTP servers defined on MS and feed it as arguments to > >>>>>> system vms On initial start of the system vm, check if you can > >>>>>> access ntp servers defined on MS vm, if not, check if you can > >>>>>> access pool.ntp.org servers - if none defined - use hypervisor > >>>>>> tools sync > >>>>>> > >>>>>> Long term solution: > >>>>>> When adding zones, define NTP servers in UI to be used with > >>>>>> system VMs > >>>>> or bypass NTP servers and allow vm-tools time sync with hypervisor. > >>>>>> > >>>>>> Thoughts? > >>>>>> > >>>>>> Thanks > >>>>>> ilya > >>>>>> > >>>>>>> -----Original Message----- > >>>>>>> From: Chip Childers [mailto:chip.child...@sungard.com] > >>>>>>> Sent: Wednesday, May 29, 2013 2:30 PM > >>>>>>> To: dev@cloudstack.apache.org > >>>>>>> Subject: [DISCUSS] How to best do time sync. (WAS: [VOTE] > >>>>>>> Release Apache CloudStack 4.1.0 (fifth round)) > >>>>>>> > >>>>>>> Ilya, > >>>>>>> > >>>>>>> I'm breaking off a new thread for this discussion. If you want > >>>>>>> to discuss the design options presented in the jira, this would > >>>>>>> be a good thread for that. ;-) > >>>>>>> > >>>>>>> -chip > >>>>>>> > >>>>>>> On Wed, May 29, 2013 at 06:24:27PM +0000, Musayev, Ilya wrote: > >>>>>>>> John, > >>>>>>>> > >>>>>>>> I clearly see your concern, please review my response under > >>>>>>>> CLOUDSTACK- > >>>>>>> 2492. > >>>>>>>> > >>>>>>>> Thanks > >>>>>>>> ilya > >>>>>>>> > >>>>>>>>> -----Original Message----- > >>>>>>>>> From: John Burwell [mailto:jburw...@basho.com] > >>>>>>>>> Sent: Wednesday, May 29, 2013 10:10 AM > >>>>>>>>> To: dev@cloudstack.apache.org > >>>>>>>>> Subject: Re: [VOTE] Release Apache CloudStack 4.1.0 (fifth > >>>>>>>>> round) > >>>>>>>>> > >>>>>>>>> -0. I don't believe we should be shipping a release with > >>>>>>>>> known clock sync issues (see CLOUDSTACK- > >>>>>>>>> 2492<https://issues.apache.org/jira/browse/CLOUDSTACK- > >> 2492>). > >>>>>>>>> Since the community voted to go forward, I will not cast a -1. > >>>>>>>>> However, I feel it is important to highlight operational > >>>>>>>>> issues that, in my view, a system such as CloudStack should > >>>>>>>>> never knowingly > >>>>>>> ship. > >>>>>>>>> > >>>>>>>>> -John > > > >
