On 1/16/13 3:28 PM, "Prachi Damle" <prachi.da...@citrix.com> wrote:
>Yes, applying the affinity/anti-affinity rules can be done at the Planner >during allocation. So the rules will apply anytime (first deploy, >stop-start, migrate, HA) the planner gets invoked. We could introduce a >separate planner for processing affinity. > >Chiradeep, >Question about hypervisor affinity: Doesn't template selection guarantee >hypervisor affinity already? User has to select a template for deployVM >always. [chiradeep] Not really, the user creates anti-affinity group "webvms" and deploys 3 Centos 5.6 VHD templates in that group. Each vm will then end up on a separate host. >-----Original Message----- >From: Chip Childers [mailto:chip.child...@sungard.com] >Sent: Monday, January 07, 2013 6:30 AM >To: cloudstack-dev@incubator.apache.org >Subject: Re: [DISCUSS] Affinity / Anti-affinity Rules > >On Mon, Jan 7, 2013 at 1:22 AM, Chris Sears <chris.x.se...@sungard.com> >wrote: >> Greetings, >> >> I understand the motivation for a feature like this, but I'm concerned >> that the concepts of affinity and anti-affinity might not be >> appropriate cloud-level abstractions to expose to end users. Also, it >> might be difficult to effectively automate decisions about fault and >> performance domains, both of which would vary greatly between >>deployments. >> >> Using anti-affinity rules to make sure HA-related VMs aren't placed on >> the same host seems like the most critical use case. What if we >> narrowed the scope of the feature to just address that issue? Building >> on Chiradeep's idea, VMs could have an anti-affinity group attribute. >> VMs in the same anti-affinity group must be placed on different hosts. >> For the first implementation, the guarantee would only apply to initial >>provisioning. > >It could actually apply any time a planner is used to select a host >(which I think also includes CloudStack "HA"). > >> @Manan, would that be sufficient? >> >> Regards >> >> - Chris >> >> >> On Fri, Jan 4, 2013 at 6:50 PM, Prachi Damle >><prachi.da...@citrix.com>wrote: >> >>> Yes, requirements seem vague. What parameters define >>> affinity/anti-affinity? >>> >>> Requirements mention >>> >> For each VM, users should be able to provide both (Affinity VMs >>> >> and >>> Anti-affinity VMs) lists concurrently. For example, VM-A can have >>> affinity with VMs B & C and anti-affinity with VMs D & E at the same >>>time. >>> >> When configuring Affinity / anti-affinity for a VM, users should >>> >> be >>> allowed to provide a list of affinity / anti-affinity VMs (via API) >>> or select affinity /anti-affinity VMs from a list (via UI) >>> >>> When user specifies VM-A can have affinity with VMs B & C does that >>> mean they should be placed on same pod or same hypervisor(cluster or >>> host) by the allocation logic? >>> >>> -Prachi >>> -----Original Message----- >>> From: Chiradeep Vittal [mailto:chiradeep.vit...@citrix.com] >>> Sent: Thursday, January 03, 2013 6:06 PM >>> To: CloudStack DeveloperList >>> Subject: Re: [DISCUSS] Affinity / Anti-affinity Rules >>> >>> Actually the proposal is quite vague. >>> What does affinity mean to the end-user? >>> What guarantees are being asked for? >>> - the vms are on the same hypervisor (affinity) >>> - the vms are not on the same hypervisor (anti) >>> - the vms are interconnected by a high-speed interconnect (affinity) >>> - the vms are in different failure domains (host/cluster/pod) >>> >>> I find the concept of affinity groups useful. >>> A possible workflow would be >>> 1. Create an affinity group of type 'Foo' >>> 1a. Group type indicates the guarantee 2. Create a VM in the group >>> >>> VMs can only leave groups on vm destruction. >>> >>> But without the specific type of guarantee, it is hard to discuss >>> this proposal. >>> >>> On 1/3/13 4:23 PM, "Manan Shah" <manan.s...@citrix.com> wrote: >>> >>> >Hi, >>> > >>> >I would like to propose a new feature for enabling Affinity / >>> >Anti-affinity rules in CS 4.1. I have created a JIRA ticket and >>> >provided the requirements at the following location. Please provide >>> >feedback on the requirements. >>> > >>> >JIRA Ticket: https://issues.apache.org/jira/browse/CLOUDSTACK-739 >>> >Requirements: >>> >https://cwiki.apache.org/confluence/display/CLOUDSTACK/Affinity+-+An >>> >ti- >>> >aff >>> >i >>> >nity+rules >>> > >>> > >>> >Regards, >>> >Manan Shah >>> > >>> >>> >>>
