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Posted to dev@cloudstack.apache.org by "Kelcey Damage (BT)" <ke...@backbonetechnology.com> on 2013/02/28 04:59:39 UTC
RE: HA question
Hi,
I can’t remember, do we enable HA on a per host basis, or on a per cluster basis?
Thanks.
http://www.backbone.gr/media/backbone_symbol1.pngKelcey Damage
Infrastructure Systems Architect
<http://www.backbonetechnology.com/> www.backbonetechnology.com
-------------------------------------------------------------------------
<ma...@backbonetechnology.com> kelcey@backbonetechnology.com
address: 55 East 7th Ave, Vancouver, BC, V5T 1M4
tel: +1 604 713 8560 ext:114
fax: +1 604 605 0964
skype: kelcey.damage
RE: HA question
Posted by Sateesh Chodapuneedi <sa...@citrix.com>.
> -----Original Message-----
> From: Hari Kannan [mailto:hari.kannan@citrix.com]
> Sent: 28 February 2013 10:36
> To: kdamage@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.
Yes, wanted to add more here...
VMware provides granular options at level of VM to override the cluster lelvel setting.
That means even if a host in a HA enabled cluster, crashes, only those VMs that are
marked for HA would be taken care. Apart from that it is also possible to override
other HA parameters like priority etc.
Regards,
Sateesh
>
> 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:kelcey@backbonetechnology.com] On Behalf
> Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
> >> >>-------------------------------------------------------------------
> >> >>-
> >> >>-----
> >>
> >>>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
> >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
> >> >>
> >> >
> >> >
>
RE: HA question
Posted by kd...@apache.org.
I have set up a placeholder @
https://cwiki.apache.org/confluence/display/CLOUDSTACK/CloudStack+HA
I will start and compile data here and then format as time goes on,
everybody feel to deposit chunks of data and I will parse through and sort.
Also I am not familiar with how to add this to our index page, can I get
some assistance on that?
Thanks
-Kelcey
>-----Original Message-----
>From: Kelceydamage@bbits [mailto:kelcey@bbits.ca]
>Sent: Thursday, February 28, 2013 9:58 AM
>To: cloudstack-dev@incubator.apache.org
>Cc: cloudstack-dev@incubator.apache.org; aemneina@gmail.com
>Subject: Re: HA question
>
>I guess this would have to be tested on other hypervisors as well.
>
>Unfortunately I get a lot of XS answers, and very few others.
>
>Thanks for the tip Clayton I'll add this to the wiki section once it's up.
>
>Sent from my iPhone
>
>On Feb 28, 2013, at 9:27 AM, Clayton Weise <cw...@iswest.net> 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.
>>
>> I haven't had a chance to test it myself to any large degree but from
some
>conversations I have had with CloudPlatform support (the paid product), we
>had an incident that ran us into a very similar situation. Due to a bug in
>XenServer 6.0.0 we went through the upgrade process to 6.0.2 and during
>that process some of the VMs got moved to other hosts and we lost track of
>things. To my delight, CloudStack picked up on this and updated itself as
to
>the host where the VM was now residing.
>>
>> What this means to me is that if some _other_ mechanism outside of CS
>were to move VMs around within a cluster (for example, due to a host
failure)
>CS would eventually query XAPI and find out where the VM resides and
>update the CS database. Now, like I said, I haven't tested this but in
theory
>this means that if you enabled HA on your hypervisor directly and
instructed
>CS to not do HA, if there was a host failure your hypervisor would take
over
>the HA process and CS would eventually update itself to recognize the re-
>arranging of VMs in the cluster... in theory.
Re: HA question
Posted by "Kelceydamage@bbits" <ke...@bbits.ca>.
I guess this would have to be tested on other hypervisors as well.
Unfortunately I get a lot of XS answers, and very few others.
Thanks for the tip Clayton I'll add this to the wiki section once it's up.
Sent from my iPhone
On Feb 28, 2013, at 9:27 AM, Clayton Weise <cw...@iswest.net> 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.
>
> I haven't had a chance to test it myself to any large degree but from some conversations I have had with CloudPlatform support (the paid product), we had an incident that ran us into a very similar situation. Due to a bug in XenServer 6.0.0 we went through the upgrade process to 6.0.2 and during that process some of the VMs got moved to other hosts and we lost track of things. To my delight, CloudStack picked up on this and updated itself as to the host where the VM was now residing.
>
> What this means to me is that if some _other_ mechanism outside of CS were to move VMs around within a cluster (for example, due to a host failure) CS would eventually query XAPI and find out where the VM resides and update the CS database. Now, like I said, I haven't tested this but in theory this means that if you enabled HA on your hypervisor directly and instructed CS to not do HA, if there was a host failure your hypervisor would take over the HA process and CS would eventually update itself to recognize the re-arranging of VMs in the cluster... in theory.
RE: HA question
Posted by Clayton Weise <cw...@iswest.net>.
> 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.
I haven't had a chance to test it myself to any large degree but from some conversations I have had with CloudPlatform support (the paid product), we had an incident that ran us into a very similar situation. Due to a bug in XenServer 6.0.0 we went through the upgrade process to 6.0.2 and during that process some of the VMs got moved to other hosts and we lost track of things. To my delight, CloudStack picked up on this and updated itself as to the host where the VM was now residing.
What this means to me is that if some _other_ mechanism outside of CS were to move VMs around within a cluster (for example, due to a host failure) CS would eventually query XAPI and find out where the VM resides and update the CS database. Now, like I said, I haven't tested this but in theory this means that if you enabled HA on your hypervisor directly and instructed CS to not do HA, if there was a host failure your hypervisor would take over the HA process and CS would eventually update itself to recognize the re-arranging of VMs in the cluster... in theory.
Re: HA question
Posted by "Kelceydamage@bbits" <ke...@bbits.ca>.
Cool, more fuel to get a proper section on HA.
Sent from my iPhone
On Feb 27, 2013, at 11:51 PM, Nitin Mehta <Ni...@citrix.com> wrote:
> 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" <mi...@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:kelcey@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 <Ni...@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" <ke...@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 <ae...@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
>>>>> <mi...@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.neelarapu@citrix.com]
>>>>>> Sent: Thursday, February 28, 2013 1:21 PM
>>>>>> To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
>>>>>> Sent: Thursday, February 28, 2013 10:36 AM
>>>>>> To: kdamage@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:kelcey@backbonetechnology.com] On
>>>>>> Behalf Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>>>>>>>>>> ---------------------------------------------------------------
>>>>>>>>>> ----
>>>>>>>>>> -
>>>>>>>>>> -----
>>>>>>>>
>>>>>>>>> kelcey@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
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>
>
Re: HA question
Posted by Nitin Mehta <Ni...@citrix.com>.
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" <mi...@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:kelcey@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 <Ni...@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" <ke...@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 <ae...@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
>>>> <mi...@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.neelarapu@citrix.com]
>>>>> Sent: Thursday, February 28, 2013 1:21 PM
>>>>> To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
>>>>> Sent: Thursday, February 28, 2013 10:36 AM
>>>>> To: kdamage@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:kelcey@backbonetechnology.com] On
>>>>> Behalf Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>>>>>>>>> ---------------------------------------------------------------
>>>>>>>>> ----
>>>>>>>>> -
>>>>>>>>> -----
>>>>>>>
>>>>>>>> kelcey@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
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>
>>>>>
>>>>>
>>
RE: HA question
Posted by Mice Xia <mi...@tcloudcomputing.com>.
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:kelcey@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 <Ni...@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" <ke...@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 <ae...@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
>>> <mi...@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.neelarapu@citrix.com]
>>>> Sent: Thursday, February 28, 2013 1:21 PM
>>>> To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
>>>> Sent: Thursday, February 28, 2013 10:36 AM
>>>> To: kdamage@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:kelcey@backbonetechnology.com] On
>>>> Behalf Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>>>>>>>> ---------------------------------------------------------------
>>>>>>>> ----
>>>>>>>> -
>>>>>>>> -----
>>>>>>
>>>>>>> kelcey@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
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>
>>>>
>>>>
>
Re: HA question
Posted by "Kelceydamage@bbits" <ke...@bbits.ca>.
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 <Ni...@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" <ke...@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 <ae...@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
>>> <mi...@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.neelarapu@citrix.com]
>>>> Sent: Thursday, February 28, 2013 1:21 PM
>>>> To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
>>>> Sent: Thursday, February 28, 2013 10:36 AM
>>>> To: kdamage@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:kelcey@backbonetechnology.com] On
>>>> Behalf
>>>> Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>>>>>>>> -------------------------------------------------------------------
>>>>>>>> -
>>>>>>>> -----
>>>>>>
>>>>>>> kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
>>>>> 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
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>
>>>>
>>>>
>
Re: HA question
Posted by Nitin Mehta <Ni...@citrix.com>.
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" <ke...@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 <ae...@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
>><mi...@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.neelarapu@citrix.com]
>>> Sent: Thursday, February 28, 2013 1:21 PM
>>> To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
>>> Sent: Thursday, February 28, 2013 10:36 AM
>>> To: kdamage@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:kelcey@backbonetechnology.com] On
>>>Behalf
>>> Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>>>>>>> -------------------------------------------------------------------
>>>>>>> -
>>>>>>> -----
>>>>>
>>>>>> kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
>>>> 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
>>>>>>>
>>>>>>
>>>>>>
>>>
>>>
>>>
Re: HA question
Posted by "Kelceydamage@bbits" <ke...@bbits.ca>.
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 <ae...@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 <mi...@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.neelarapu@citrix.com]
>> Sent: Thursday, February 28, 2013 1:21 PM
>> To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
>> Sent: Thursday, February 28, 2013 10:36 AM
>> To: kdamage@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:kelcey@backbonetechnology.com] On Behalf
>> Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>>>>>> -------------------------------------------------------------------
>>>>>> -
>>>>>> -----
>>>>
>>>>> kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
>>> 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
>>>>>>
>>>>>
>>>>>
>>
>>
>>
Re: HA question
Posted by Ahmad Emneina <ae...@gmail.com>.
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 <mi...@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.neelarapu@citrix.com]
> Sent: Thursday, February 28, 2013 1:21 PM
> To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
> Sent: Thursday, February 28, 2013 10:36 AM
> To: kdamage@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:kelcey@backbonetechnology.com] On Behalf
> Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
> >> >>-------------------------------------------------------------------
> >> >>-
> >> >>-----
> >>
> >>>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
> >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
> >> >>
> >> >
> >> >
>
>
>
RE: HA question
Posted by Mice Xia <mi...@tcloudcomputing.com>.
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.neelarapu@citrix.com]
Sent: Thursday, February 28, 2013 1:21 PM
To: cloudstack-dev@incubator.apache.org; kdamage@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.kannan@citrix.com]
Sent: Thursday, February 28, 2013 10:36 AM
To: kdamage@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:kelcey@backbonetechnology.com] On Behalf Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>> >>-------------------------------------------------------------------
>> >>-
>> >>-----
>>
>>>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
>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
>> >>
>> >
>> >
RE: HA question
Posted by Sanjeev Neelarapu <sa...@citrix.com>.
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.kannan@citrix.com]
Sent: Thursday, February 28, 2013 10:36 AM
To: kdamage@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:kelcey@backbonetechnology.com] On Behalf Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>> >>-------------------------------------------------------------------
>> >>-
>> >>-----
>>
>>>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
>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
>> >>
>> >
>> >
RE: HA question
Posted by Hari Kannan <ha...@citrix.com>.
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:kelcey@backbonetechnology.com] On Behalf Of kdamage@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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>> >>-------------------------------------------------------------------
>> >>-
>> >>-----
>>
>>>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
>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
>> >>
>> >
>> >
RE: HA question
Posted by kd...@apache.org.
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.chodapuneedi@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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>> >>--------------------------------------------------------------------
>> >>-----
>>
>>>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.co
>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
>> >>
>> >
>> >
RE: HA question
Posted by Sateesh Chodapuneedi <sa...@citrix.com>.
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.Mehta@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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
> >>-------------------------------------------------------------------------
> >>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.com
> >>>
> >>
> >>address: 55 East 7th Ave, Vancouver, BC, V5T 1M4
> >>tel: +1 604 713 8560 ext:114
> >>fax: +1 604 605 0964
> >>skype: kelcey.damage
> >>
> >
> >
RE: HA question
Posted by Hari Kannan <ha...@citrix.com>.
Hi Kelsey,
Not sure I understand this question :-) There is no HA for hosts - what is being protected is the VM, not the host..
Hari
-----Original Message-----
From: Kelcey Damage (BT) [mailto:kelcey@backbonetechnology.com] On Behalf Of kdamage@apache.org
Sent: Wednesday, February 27, 2013 8:25 PM
To: cloudstack-dev@incubator.apache.org
Cc: Hari Kannan
Subject: RE: HA question
Thanks that’s 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.kannan@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 “Dedicated” 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:kelcey@backbonetechnology.com]
>Sent: Wednesday, February 27, 2013 8:00 PM
>To: CloudStack dev list
>Subject: RE: HA question
>
>Hi,
>
>I can’t 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/>
>-----------------------------------------------------------------------
>-- kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.com
>>
>
>address: 55 East 7th Ave, Vancouver, BC, V5T 1M4
>tel: +1 604 713 8560 ext:114
>fax: +1 604 605 0964
>skype: kelcey.damage
>
Re: HA question
Posted by Nitin Mehta <Ni...@citrix.com>.
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, "kdamage@apache.org" <kd...@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.kannan@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:kelcey@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/>
>>-------------------------------------------------------------------------
>>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.com
>>>
>>
>>address: 55 East 7th Ave, Vancouver, BC, V5T 1M4
>>tel: +1 604 713 8560 ext:114
>>fax: +1 604 605 0964
>>skype: kelcey.damage
>>
>
>
RE: HA question
Posted by kd...@apache.org.
Thanks that’s 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.kannan@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 “Dedicated” 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:kelcey@backbonetechnology.com]
>Sent: Wednesday, February 27, 2013 8:00 PM
>To: CloudStack dev list
>Subject: RE: HA question
>
>Hi,
>
>I can’t 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/>
>-------------------------------------------------------------------------
>kelcey@backbonetechnology.com<mailto:kelcey@backbonetechnology.com
>>
>
>address: 55 East 7th Ave, Vancouver, BC, V5T 1M4
>tel: +1 604 713 8560 ext:114
>fax: +1 604 605 0964
>skype: kelcey.damage
>
RE: HA question
Posted by Hari Kannan <ha...@citrix.com>.
Hi Kelsey,
HA is at 2 levels – VMs can be marked HA. In addition, you can mark some hosts as reserved for “Dedicated” 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:kelcey@backbonetechnology.com]
Sent: Wednesday, February 27, 2013 8:00 PM
To: CloudStack dev list
Subject: RE: HA question
Hi,
I can’t 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/>
-------------------------------------------------------------------------
kelcey@backbonetechnology.com<ma...@backbonetechnology.com>
address: 55 East 7th Ave, Vancouver, BC, V5T 1M4
tel: +1 604 713 8560 ext:114
fax: +1 604 605 0964
skype: kelcey.damage