Mailing List Archive

Re: [Xen-devel] Re: FT for XCP
On Mon, Sep 26, 2011 at 8:58 AM, R J <torushikeshj@gmail.com> wrote:

> Hello Mike,
>
> Thank you for suggestion. I would love to incorporate remus in xapi if
> thats possible.
>

Great. That would be certainly welcome. [I am not a fan of ocaml ;)]

Remus as its inbuilt logic of detecting checkpoint failure and taking
> decisions accordingly.
>
> I think there is remus support for xen 3.4
>
>
What matters is the toolstack.
a. I am not sure if the xe toolstack uses libxenguest (tools/libxc) and
if it does, then it should have the basic remus support already.

b. I am also not sure if it is recent enough to include all the remus bug
fixes that went in over the last 6 months.

What do you suggest as my next step ?
>
>
Most of the remus code is python based and completely self contained. It
just needs
the domU's info (disk paths & vifs) as an s-expression. There is only one
api call to
Xend- to obtain the domU's s-expression.

1. A quick and dirty way would be to change this single api call to xapi
equivalent
and obtain the s-expression, then you should have Remus running.

2. Another approach would be to re-write the toolstack code in ocaml - which
might
be easy. But make sure that ocaml can make netlink api calls.

shriram

> Regards,
> Rushikesh
>
>
>
>
> On Mon, Sep 26, 2011 at 12:38 PM, Mike McClurg <mike.mcclurg@citrix.com>wrote:
>
>> On 09/25/2011 09:11 PM, R J wrote:
>>
>> Hello List,
>>
>> I have a proposal and wont mind to implement my self but need a helping
>> hand to start on.
>> I want to implement the aggressive FT feature in XCP. The best way I could
>> imagine is the use of feature *Live Migration*
>>
>> Steps
>> 1. Enable the FT of a particular VM using xe commands and adding as a
>> param to that VM e.g. xe vm-param-set FT=true uuid=XYZ
>> 2. If the FT = true detected by xenstore then xapi will initiate a live
>> migrate of that VM to any of available host.
>> 3. A parallel "network ping"/"xapi heartbit" from/to that host could be
>> initialized for each FT VM.
>> 4. Live migrate will run forever until its disabled by FT = false or one
>> of the host is down. e.g. the process will loop at 99.99% migration state
>> 5. If there is a packet drop of x packets the VM Migrate procedure will
>> mark the VM Migration as Complete and will switch the devices forcefully.
>> -- this could result in some data loss but I dont have any alternative to
>> this.
>> -- The specific x packets can be set by XCP but we cant rely for default
>> XCP Errors
>> 6. If there is a successful migration due to host down then we will again
>> start from step2
>>
>> Above steps I have assumed to my knowledge, we can discuss the problems in
>> it.
>>
>> Apologies if I'm being too naive.
>>
>> Regards,
>> Rushikesh
>>
>> This sounds like Remus (http://nss.cs.ubc.ca/remus/). Are you proposing
>> to implement Remus support in xapi?
>>
>> Mike
>>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
>
Re: [Xen-devel] Re: FT for XCP [ In reply to ]
Thanks Shriram,

I thought of using the native VM migrate code but in that case I may end up
with corruption either in NW, DIsk or Mem.
The remus page is not updated. http://nss.cs.ubc.ca/remus/hg/ I hope this
project is not stopped.

I'm still learning xen-3.4.2/tools path so hopefully I'll get some direction
which can save from corruption.

Regards,
R J



On Wed, Sep 28, 2011 at 9:38 PM, Shriram Rajagopalan <rshriram@cs.ubc.ca>wrote:

>
>
> On Mon, Sep 26, 2011 at 8:58 AM, R J <torushikeshj@gmail.com> wrote:
>
>> Hello Mike,
>>
>> Thank you for suggestion. I would love to incorporate remus in xapi if
>> thats possible.
>>
>
> Great. That would be certainly welcome. [I am not a fan of ocaml ;)]
>
> Remus as its inbuilt logic of detecting checkpoint failure and taking
>> decisions accordingly.
>>
>> I think there is remus support for xen 3.4
>>
>>
> What matters is the toolstack.
> a. I am not sure if the xe toolstack uses libxenguest (tools/libxc) and
> if it does, then it should have the basic remus support already.
>
> b. I am also not sure if it is recent enough to include all the remus bug
> fixes that went in over the last 6 months.
>
> What do you suggest as my next step ?
>>
>>
> Most of the remus code is python based and completely self contained. It
> just needs
> the domU's info (disk paths & vifs) as an s-expression. There is only one
> api call to
> Xend- to obtain the domU's s-expression.
>
> 1. A quick and dirty way would be to change this single api call to xapi
> equivalent
> and obtain the s-expression, then you should have Remus running.
>
> 2. Another approach would be to re-write the toolstack code in ocaml -
> which might
> be easy. But make sure that ocaml can make netlink api calls.
>
> shriram
>
>> Regards,
>> Rushikesh
>>
>>
>>
>>
>> On Mon, Sep 26, 2011 at 12:38 PM, Mike McClurg <mike.mcclurg@citrix.com>wrote:
>>
>>> On 09/25/2011 09:11 PM, R J wrote:
>>>
>>> Hello List,
>>>
>>> I have a proposal and wont mind to implement my self but need a helping
>>> hand to start on.
>>> I want to implement the aggressive FT feature in XCP. The best way I
>>> could imagine is the use of feature *Live Migration*
>>>
>>> Steps
>>> 1. Enable the FT of a particular VM using xe commands and adding as a
>>> param to that VM e.g. xe vm-param-set FT=true uuid=XYZ
>>> 2. If the FT = true detected by xenstore then xapi will initiate a live
>>> migrate of that VM to any of available host.
>>> 3. A parallel "network ping"/"xapi heartbit" from/to that host could be
>>> initialized for each FT VM.
>>> 4. Live migrate will run forever until its disabled by FT = false or one
>>> of the host is down. e.g. the process will loop at 99.99% migration state
>>> 5. If there is a packet drop of x packets the VM Migrate procedure will
>>> mark the VM Migration as Complete and will switch the devices forcefully.
>>> -- this could result in some data loss but I dont have any alternative to
>>> this.
>>> -- The specific x packets can be set by XCP but we cant rely for default
>>> XCP Errors
>>> 6. If there is a successful migration due to host down then we will again
>>> start from step2
>>>
>>> Above steps I have assumed to my knowledge, we can discuss the problems
>>> in it.
>>>
>>> Apologies if I'm being too naive.
>>>
>>> Regards,
>>> Rushikesh
>>>
>>> This sounds like Remus (http://nss.cs.ubc.ca/remus/). Are you proposing
>>> to implement Remus support in xapi?
>>>
>>> Mike
>>>
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>>
>>
>
Re: [Xen-devel] Re: FT for XCP [ In reply to ]
On Sun, Oct 09, 2011 at 01:16:46AM +0530, R J wrote:
> Thanks Shriram,
>
> I thought of using the native VM migrate code but in that case I may end
> up with corruption either in NW, DIsk or Mem.
> The remus page is not updated. [1]http://nss.cs.ubc.ca/remus/hg/ I hope
> this project is not stopped.
>

There's also: http://wiki.xen.org/xenwiki/Remus

-- Pasi

> I'm still learning xen-3.4.2/tools path so hopefully I'll get some
> direction which can save from corruption.
>
> Regards,
> R J
>
> On Wed, Sep 28, 2011 at 9:38 PM, Shriram Rajagopalan
> <[2]rshriram@cs.ubc.ca> wrote:
>
> On Mon, Sep 26, 2011 at 8:58 AM, R J <[3]torushikeshj@gmail.com> wrote:
>
> Hello Mike,
>
> Thank you for suggestion. I would love to incorporate remus in xapi if
> thats possible.
>
> Great. That would be certainly welcome. [I am not a fan of ocaml ;)]
>
> Remus as its inbuilt logic of detecting checkpoint failure and taking
> decisions accordingly.
>
> I think there is remus support for xen 3.4
>
> What matters is the toolstack.
> a. I am not sure if the xe toolstack uses libxenguest (tools/libxc) and
> if it does, then it should have the basic remus support already.
>
> b. I am also not sure if it is recent enough to include all the remus
> bug
> fixes that went in over the last 6 months.
>
> What do you suggest as my next step ?
>
> Most of the remus code is python based and completely self contained. It
> just needs
> the domU's info (disk paths & vifs) as an s-expression. There is only
> one api call to
> Xend- to obtain the domU's s-expression.
>
> 1. A quick and dirty way would be to change this single api call to xapi
> equivalent
> and obtain the s-expression, then you should have Remus running.
>
> 2. Another approach would be to re-write the toolstack code in ocaml -
> which might
> be easy. But make sure that ocaml can make netlink api calls.
>
> shriram
>
> Regards,
> Rushikesh
>
> On Mon, Sep 26, 2011 at 12:38 PM, Mike McClurg
> <[4]mike.mcclurg@citrix.com> wrote:
>
> On 09/25/2011 09:11 PM, R J wrote:
>
> Hello List,
>
> I have a proposal and wont mind to implement my self but need a
> helping hand to start on.
> I want to implement the aggressive FT feature in XCP. The best way
> I could imagine is the use of feature *Live Migration*
>
> Steps
> 1. Enable the FT of a particular VM using xe commands and adding
> as a param to that VM e.g. xe vm-param-set FT=true uuid=XYZ
> 2. If the FT = true detected by xenstore then xapi will initiate a
> live migrate of that VM to any of available host.
> 3. A parallel "network ping"/"xapi heartbit" from/to that host
> could be initialized for each FT VM.
> 4. Live migrate will run forever until its disabled by FT = false
> or one of the host is down. e.g. the process will loop at 99.99%
> migration state
> 5. If there is a packet drop of x packets the VM Migrate procedure
> will mark the VM Migration as Complete and will switch the devices
> forcefully.
> -- this could result in some data loss but I dont have any
> alternative to this.
> -- The specific x packets can be set by XCP but we cant rely for
> default XCP Errors
> 6. If there is a successful migration due to host down then we
> will again start from step2
>
> Above steps I have assumed to my knowledge, we can discuss the
> problems in it.
>
> Apologies if I'm being too naive.
>
> Regards,
> Rushikesh
>
> This sounds like Remus ([5]http://nss.cs.ubc.ca/remus/). Are you
> proposing to implement Remus support in xapi?
> Mike
>
> _______________________________________________
> Xen-devel mailing list
> [6]Xen-devel@lists.xensource.com
> [7]http://lists.xensource.com/xen-devel
>
> References
>
> Visible links
> 1. http://nss.cs.ubc.ca/remus/hg/
> 2. mailto:rshriram@cs.ubc.ca
> 3. mailto:torushikeshj@gmail.com
> 4. mailto:mike.mcclurg@citrix.com
> 5. http://nss.cs.ubc.ca/remus/
> 6. mailto:Xen-devel@lists.xensource.com
> 7. http://lists.xensource.com/xen-devel

> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel


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