Open Stack

On 7/16/14, 2:43 PM, "Clint Byrum" <clint at fewbar.com> wrote:

>Excerpts from Mike Spreitzer's message of 2014-07-16 10:50:42 -0700:
>> Clint Byrum <clint at fewbar.com> wrote on 07/02/2014 01:54:49 PM:
>> 
>> > Excerpts from Qiming Teng's message of 2014-07-02 00:02:14 -0700:
>> > > Just some random thoughts below ...
>> > > 
>> > > On Tue, Jul 01, 2014 at 03:47:03PM -0400, Mike Spreitzer wrote:
>> > > > In AWS, an autoscaling group includes health maintenance
>> > functionality ---
>> > > > both an ability to detect basic forms of failures and an
>>abilityto 
>> react 
>> > > > properly to failures detected by itself or by a load balancer.
>>What 
>> is 
>> > > > the thinking about how to get this functionality in OpenStack?
>>Since 
>> 
>> > > 
>> > > We are prototyping a solution to this problem at IBM Research -
>>China
>> > > lab.  The idea is to leverage oslo.messaging and ceilometer events
>>for
>> > > instance (possibly other resource such as port, securitygroup ...)
>> > > failure detection and handling.
>> > > 
>> > 
>> > Hm.. perhaps you should be contributing some reviews here as you may
>> > have some real insight:
>> > 
>> > https://review.openstack.org/#/c/100012/
>> > 
>> > This sounds a lot like what we're working on for continuous
>>convergence.
>> 
>> I noticed that health checking in AWS goes beyond convergence.  In AWS
>>an 
>> ELB can be configured with a URL to ping, for application-level health
>> checking.  And an ASG can simply be *told* the health of a member by a
>> user's own external health system.  I think we should have analogous
>> functionality in OpenStack.  Does that make sense to you?  If so, do
>>you 
>> have any opinion on the right way to integrate, so that we do not have
>> three completely independent health maintenance systems?
>
>The check url is already a part of Neutron LBaaS IIRC. What may not be
>a part is notifications for when all members are reporting down (which
>might be something to trigger scale-up).

You do recall correctly, and there are currently no mechanisms for
notifying anything outside of the load balancer backend when the health
monitor/member state changes.

There is also currently no way for an external system to inject health
information about an LB or its members.

Both would be interesting additions.

doug


>
>If we don't have push checks in our auto scaling implementation then we
>don't have a proper auto scaling implementation.
>
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