Comments inline. 

Thanks,
Prachi

-----Original Message-----
From: Sangeetha Hariharan [mailto:sangeetha.hariha...@citrix.com] 
Sent: Monday, April 01, 2013 5:45 PM
To: cloudstack-...@incubator.apache.org
Subject: RE: [DISCUSS] Affinity / Anti-affinity Rules

Had the following questions after going over the spec - 
https://cwiki.apache.org/confluence/display/CLOUDSTACK/FS+-+Affinity-Anti-affinity+groups
 :

1.In the API changes section - For all the API calls listed can we include if 
the parameters are optional/Required?

2.Can new DB changes introduced by this feature be included  ?

[Prachi] Will update FS with this info.

3.CreateAffinityGroup API: 
Using this API can admin/domain admin user be able to create an affinity group 
for other accounts to use ? Or can it be created only for its own consumption?

[Prachi] No, affinity groups can be created and used by individual account 
only. Affinity groups are a way for the user to specify her/his deployment 
preference, so the visibility/usage is limited to the account only.

4.ListAffinityGroups API:
Will admin/domain admin user be able to list the affinity groups of the other 
regular users ?

[Prachi] No, same as above.

5.DeleteAffinityGroup API:
Can this API  be used to delete an Affinity Group / Can it be used to only to 
remove an existing VM from an affinity group? 
Why is there a need to pass AccountName and DomainId for this API call ? Is 
Affinity Group Id not enough to uniquely identify this entity ?

[Prachi] It is for deleting groups of an account. The API also takes in the 
user-friendly group name too, in which case the account info is needed.
To delete VM's association to the group, updateVMAffinityGroup API will serve 
the purpose.

6. Will Affinity rules apply when we stop and start the Vms? Will it be applied 
when CloudStack performs HA ? 

[Prachi] Yes. 

7.When User tries to migrate/live migrate the VM , will the action to migrate a 
VM to a host that does not satisfy the affinity rule fail ?

[Prachi] When root Admin lists hosts available for live migration, CS will 
indicate the hosts that do not fit the affinity rules as 'Not Suitable'. If 
admin still goes ahead and migrates to such a host, migration will proceed.

8.DeployVirtualMachine API:  It is mentioned in the FS that  affinitygroupids 
OR affinitygroupnames need to be passed. If both are passed will the API fail ?

[Prachi] yes

9.Is there any difference in implementation for this feature between a Basic 
Zone and Advanced zone ?  

[Prachi] Nope

10. In cases where there is a mismatch between service offering (host tag and 
storage tag) and anti-affinity group that the Vm is being deployed with , will 
the error message provided to the user be informative enough to know why the 
deployment failure happened (due to service offerings vs anti-affinity group) 
to take corrective actions?

[Prachi] No, it will still throw out the generic InsufficentCapacity error - 
and this is correct, since the underlying error is still not enough compute or 
storage capacity in the datacenter to _match_ your needs.
The logs will however show that the affinity rules + tags are being applied - 
causing no match found.

11. When a VM is in "Stopped" state , will it continue to be  part of the 
affinity group ?  Or will its association with the affinity group be released 
immediately, so that new Vms deployed as part of this anti-affinity group can 
use the host on which the Vm was running before it was stopped.  

[Prachi] Good point. The association with affinity group is maintained. We 
never remove it unless user removes. But yes, it makes sense to avoid deploying 
new VMs in the same group, on that host. So host-anti-affinity should also 
consider last_host_id of the VM's that are in stopped state.

Thanks
Sangeetha

-----Original Message-----
From: Chiradeep Vittal [mailto:chiradeep.vit...@citrix.com] 
Sent: Friday, March 01, 2013 2:12 PM
To: cloudstack-...@incubator.apache.org
Cc: Manan Shah; Alex Huang
Subject: Re: [DISCUSS] Affinity / Anti-affinity Rules



On 3/1/13 7:14 AM, "Chip Childers" <chip.child...@sungard.com> wrote:

>On Thu, Feb 28, 2013 at 03:18:51PM -0800, Prachi Damle wrote:
>> So far per the scope of the feature, Affinity groups is an entity 
>>created by an individual account and can be used, listed only by that 
>>account.
>> 
>> Wanted to know if we see any use case where one would need to create 
>>domain-level affinity groups that  all accounts in that domain can 
>>access? I can see that this may not be useful, since users would want 
>>to have VM placement preferences exclusive to their accounts and not 
>>shared with other accounts.
>> 
>> Any thoughts?
>
>I spent time thinking about this, and I'm not sure I see a use-case for 
>it.  Others might though...
Me neither

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