I was searching for this document which used to be on docs.cloudstack.org but couldn't find it. Thanks for pointing this one.
On 28/02/13 1:12 PM, "Mice Xia" <mice_...@tcloudcomputing.com> wrote: >There is a document describing HA in details, you can check it on: >http://people.apache.org/~mice/CloudStackHighAvailability.pdf > >this document is a little outdated, but the concepts and overall workflow >still apply. > >Regards >Mice > >-----Original Message----- >From: Kelceydamage@bbits [mailto:kel...@bbits.ca] >Sent: Thursday, February 28, 2013 3:24 PM >To: cloudstack-dev@incubator.apache.org >Cc: cloudstack-dev@incubator.apache.org >Subject: Re: HA question > >I could get one started. > >I've saved this thread, and I'll try to get some stuff up in the next >couple days. > >Sent from my iPhone > >On Feb 27, 2013, at 10:57 PM, Nitin Mehta <nitin.me...@citrix.com> wrote: > >> Kelcey - Would you be willing to put a HA wiki ? I promise to >> volunteer :) with whatever I know >> >> On 28/02/13 12:16 PM, "Kelceydamage@bbits" <kel...@bbits.ca> wrote: >> >>> This is turning out to be a great discussion to have. Now I get that >>> CloudStack HA is purely handled by the management/orchestration >>> engine and only if VM is tagged(which I knew). But what is good to >>> find out is that it does not involve underlying hypervisor specific >>> HA modules(except perhaps VMware). Incidentally VMwares HA mechanism >>> is also called storage >>> heartbeat(5.x+) but it uses hypervisor modules as well. >>> >>> I do agree with Ahmad that it might be worth looking into expanding >>> our HA suite to support hypervisor specific HA modules as an override >>> to the default CS HA. >>> >>> There has not been too many HA discussions on the mailing list, and >>> by the looks of it we were all under slightly different impressions. >>> >>> Thanks again for the good discussion. >>> >>> Sent from my iPhone >>> >>> On Feb 27, 2013, at 9:48 PM, Ahmad Emneina <aemne...@gmail.com> wrote: >>> >>>> I would imagine it's best to leverage on the underlying hypervisors' >>>> HA mechanisms, configured oud-of-band of cloudstack. I find >>>> cloudstacks implementation a little laggy compared to the paid for >>>>variety. >>>> CloudStack >>>> does a well enough job to figure out which host the vm eventually >>>> lands on. >>>> >>>> >>>> On Wed, Feb 27, 2013 at 9:37 PM, Mice Xia >>>> <mice_...@tcloudcomputing.com>wrote: >>>> >>>>> Currently for xenserver/KVM, Cloudstack uses 'storage heartbeat' to >>>>> detect whether it should start HA, i.e. agent resides on >>>>> xenserver/KVM periodically writes a timestamp on shared storage, if >>>>> host network pingTimeOut happens, Cloudstack will investigate if >>>>> 'storage heartbeat' >>>>> timeout and if that's the case HA job will be launched for HA >>>>> enabled VMs on the host. >>>>> >>>>> It's a simplified procedure, HA implementation involves delta sync/ >>>>> investigators and fencers. >>>>> >>>>> -Mice >>>>> >>>>> -----Original Message----- >>>>> From: Sanjeev Neelarapu [mailto:sanjeev.neelar...@citrix.com] >>>>> Sent: Thursday, February 28, 2013 1:21 PM >>>>> To: cloudstack-dev@incubator.apache.org; kdam...@apache.org >>>>> Subject: RE: HA question >>>>> >>>>> Hi Hari, >>>>> >>>>> AFAIK, in CloudStack if a host crashes CloudStack would detect the >>>>> host as down after pingTimeout interval. >>>>> CloudStack does not reduce the available capacity because the host >>>>> capacity values are not removed from op_host_capacity table. It >>>>> assumes the host down is a temporary issue. >>>>> >>>>> Thanks, >>>>> Sanjeev >>>>> >>>>> -----Original Message----- >>>>> From: Hari Kannan [mailto:hari.kan...@citrix.com] >>>>> Sent: Thursday, February 28, 2013 10:36 AM >>>>> To: kdam...@apache.org; cloudstack-dev@incubator.apache.org >>>>> Subject: RE: HA question >>>>> >>>>> Hi Kelcey, >>>>> >>>>> At the risk of stating the obvious, I just wish to re-iterate my >>>>> earlier point - with CloudStack, HA is for VM, not for host. That >>>>> is different than VMware's HA in someways - in VMware, if a cluster >>>>> is HA, when any host crashes, all VMs on that host will be >>>>> restarted on a different host. >>>>> With >>>>> cloudstack, only VMs that are HA enabled will be restarted. >>>>> >>>>> At least, that is the way I understand this.. >>>>> >>>>> I also wonder what happens in CloudStack if a host crashes (assume >>>>> there were no VMs on it) - would CloudStack detect this host is >>>>> down and reduce the available capacity? >>>>> >>>>> Hari >>>>> >>>>> -----Original Message----- >>>>> From: Kelcey Damage (BT) [mailto:kel...@backbonetechnology.com] On >>>>> Behalf Of kdam...@apache.org >>>>> Sent: Wednesday, February 27, 2013 8:51 PM >>>>> To: cloudstack-dev@incubator.apache.org >>>>> Cc: Hari Kannan >>>>> Subject: RE: HA question >>>>> >>>>> So it's safe to conclude that HA while enabled on the host(As in >>>>> the module), must be available cluster wide(uniform cluster). This >>>>> is how VMware and others operate. >>>>> >>>>> Thanks all. >>>>> >>>>> -Kelcey >>>>> >>>>> >>>>>> -----Original Message----- >>>>>> From: Sateesh Chodapuneedi >>>>>> [mailto:sateesh.chodapune...@citrix.com] >>>>>> Sent: Wednesday, February 27, 2013 8:46 PM >>>>>> To: cloudstack-dev@incubator.apache.org >>>>>> Cc: Hari Kannan >>>>>> Subject: RE: HA question >>>>>> >>>>>> For VMware, CloudStack uses native HA provided by VMware. >>>>>> VMware provides HA at the level of cluster. >>>>>> >>>>>> Regards, >>>>>> Sateesh >>>>>> >>>>>>> -----Original Message----- >>>>>>> From: Nitin Mehta [mailto:nitin.me...@citrix.com] >>>>>>> Sent: 28 February 2013 10:13 >>>>>>> To: cloudstack-dev@incubator.apache.org >>>>>>> Cc: Hari Kannan >>>>>>> Subject: Re: HA question >>>>>>> >>>>>>> CS has its own HA logic and doesn't use the native HA of the HV >>>>>>> and so the question for enabling the HA for hosts doesn't arise. >>>>>>> This is true >>>>> for XS. >>>>>>> For Vmware and KVM, I will let the guru's speak :) >>>>>>> >>>>>>> On 28/02/13 9:55 AM, "kdam...@apache.org" <kdam...@apache.org> >>>>>> wrote: >>>>>>> >>>>>>>> Thanks that¹s awesome, but not quite the answer I was looking for. >>>>>>>> >>>>>>>> To better phrase my question, if the cluster is the basic unit >>>>>>>> of availability, when hosts are enabled for HA, must all hosts >>>>>>>> in the cluster be enabled? Or can the cluster exist with a >>>>>>>> non-uniform structure, having only some hosts enabled for HA? >>>>>>>> >>>>>>>> You partially answered it with the special reserve HA hosts, but >>>>>>>> I'm looking more in terms of general use. >>>>>>>> >>>>>>>> Thanks >>>>>>>> >>>>>>>> -kelcey >>>>>>>> >>>>>>>> >>>>>>>>> -----Original Message----- >>>>>>>>> From: Hari Kannan [mailto:hari.kan...@citrix.com] >>>>>>>>> Sent: Wednesday, February 27, 2013 8:21 PM >>>>>>>>> To: cloudstack-dev@incubator.apache.org >>>>>>>>> Subject: RE: HA question >>>>>>>>> >>>>>>>>> Hi Kelsey, >>>>>>>>> >>>>>>>>> HA is at 2 levels VMs can be marked HA. In addition, you can >>>>>>>>> mark some hosts as reserved for ³Dedicated² HA hosts. Quoting >>>>>>>>> from the manual, the dedicated HA option is set through a >>>>>>>>> special host tag when the host is created. >>>>>>>>> To allow the administrator to dedicate hosts to only HA-enabled >>>>>>>>> VMs, set the global configuration variable ha.tag to the >>>>>>>>> desired tag (for example, "ha_host"), and restart the Management >>>>>>>>>Server. >>>>>>>>> Enter the value in the Host Tags field when adding the host(s) >>>>>>>>> that you want to dedicate to HA-enabled VMs. >>>>>>>>> >>>>>>>>> Hari >>>>>>>>> >>>>>>>>> From: Kelcey Damage (BT) [mailto:kel...@backbonetechnology.com] >>>>>>>>> Sent: Wednesday, February 27, 2013 8:00 PM >>>>>>>>> To: CloudStack dev list >>>>>>>>> Subject: RE: HA question >>>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> I can¹t remember, do we enable HA on a per host basis, or on a >>>>>>>>> per cluster basis? >>>>>>>>> >>>>>>>>> Thanks. >>>>>>>>> >>>>>>>>> [cid:image001.png@01CE1524.FA0D61B0]Kelcey Damage >>>>>>>>> Infrastructure Systems Architect >>>>>>> >>>>>>>> www.backbonetechnology.com<http://www.backbonetechnology.com/> >>>>>>>>> --------------------------------------------------------------- >>>>>>>>> ---- >>>>>>>>> - >>>>>>>>> ----- >>>>>>> >>>>>>>> kel...@backbonetechnology.com<mailto:kelcey@backbonetechnology.c >>>>>>>> o >>>>>> m >>>>>>>>>> >>>>>>>>> >>>>>>>>> address: 55 East 7th Ave, Vancouver, BC, V5T 1M4 >>>>>>>>> tel: +1 604 713 8560 ext:114 >>>>>>>>> fax: +1 604 605 0964 >>>>>>>>> skype: kelcey.damage >>>>>>>>> >>>>>>>> >>>>>>>> >>>>> >>>>> >>>>> >>
