Brandon, can you please explain further (1) bellow? -----Original Message----- From: Brandon Logan [mailto:brandon.lo...@rackspace.com] Sent: Tuesday, November 25, 2014 12:23 AM To: openstack-dev@lists.openstack.org Subject: Re: [openstack-dev] [neutron][lbaas] Shared Objects in LBaaS - Use Cases that led us to adopt this.
My impression is that the statuses of each entity will be shown on a detailed info request of a loadbalancer. The root level objects would not have any statuses. For example a user makes a GET request to /loadbalancers/{lb_id} and the status of every child of that load balancer is show in a "status_tree" json object. For example: {"name": "loadbalancer1", "status_tree": {"listeners": [{"name": "listener1", "operating_status": "ACTIVE", "default_pool": {"name": "pool1", "status": "ACTIVE", "members": [{"ip_address": "10.0.0.1", "status": "OFFLINE"}]}} Sam, correct me if I am wrong. I generally like this idea. I do have a few reservations with this: 1) Creating and updating a load balancer requires a full tree configuration with the current extension/plugin logic in neutron. Since updates will require a full tree, it means the user would have to know the full tree configuration just to simply update a name. Solving this would require nested child resources in the URL, which the current neutron extension/plugin does not allow. Maybe the new one will. 2) The status_tree can get quite large depending on the number of listeners and pools being used. This is a minor issue really as it will make horizon's (or any other UI tool's) job easier to show statuses. Thanks, Brandon On Mon, 2014-11-24 at 12:43 -0800, Stephen Balukoff wrote: > Hi Samuel, > > > We've actually been avoiding having a deeper discussion about status > in Neutron LBaaS since this can get pretty hairy as the back-end > implementations get more complicated. I suspect managing that is > probably one of the bigger reasons we have disagreements around object > sharing. Perhaps it's time we discussed representing state "correctly" > (whatever that means), instead of a round-a-bout discussion about > object sharing (which, I think, is really just avoiding this issue)? > > > Do you have a proposal about how status should be represented > (possibly including a description of the state machine) if we collapse > everything down to be logical objects except the loadbalancer object? > (From what you're proposing, I suspect it might be too general to, for > example, represent the UP/DOWN status of members of a given pool.) > > > Also, from an haproxy perspective, sharing pools within a single > listener actually isn't a problem. That is to say, having the same > L7Policy pointing at the same pool is OK, so I personally don't have a > problem allowing sharing of objects within the scope of parent > objects. What do the rest of y'all think? > > > Stephen > > > > On Sat, Nov 22, 2014 at 11:06 PM, Samuel Bercovici > <samu...@radware.com> wrote: > Hi Stephen, > > > > 1. The issue is that if we do 1:1 and allow status/state > to proliferate throughout all objects we will then get an > issue to fix it later, hence even if we do not do sharing, I > would still like to have all objects besides LB be treated as > logical. > > 2. The 3rd use case bellow will not be reasonable without > pool sharing between different policies. Specifying different > pools which are the same for each policy make it non-started > to me. > > > > -Sam. > > > > > > > > From: Stephen Balukoff [mailto:sbaluk...@bluebox.net] > Sent: Friday, November 21, 2014 10:26 PM > To: OpenStack Development Mailing List (not for usage > questions) > Subject: Re: [openstack-dev] [neutron][lbaas] Shared Objects > in LBaaS - Use Cases that led us to adopt this. > > > > I think the idea was to implement 1:1 initially to reduce the > amount of code and operational complexity we'd have to deal > with in initial revisions of LBaaS v2. Many to many can be > simulated in this scenario, though it does shift the burden of > maintenance to the end user. It does greatly simplify the > initial code for v2, in any case, though. > > > > > > Did we ever agree to allowing listeners to be shared among > load balancers? I think that still might be a N:1 > relationship even in our latest models. > > > > > There's also the difficulty introduced by supporting different > flavors: Since flavors are essentially an association between > a load balancer object and a driver (with parameters), once > flavors are introduced, any sub-objects of a given load > balancer objects must necessarily be purely logical until they > are associated with a load balancer. I know there was talk of > forcing these objects to be sub-objects of a load balancer > which can't be accessed independently of the load balancer > (which would have much the same effect as what you discuss: > State / status only make sense once logical objects have an > instantiation somewhere.) However, the currently proposed API > treats most objects as root objects, which breaks this > paradigm. > > > > > > How we handle status and updates once there's an instantiation > of these logical objects is where we start getting into real > complexity. > > > > > > It seems to me there's a lot of complexity introduced when we > allow a lot of many to many relationships without a whole lot > of benefit in real-world deployment scenarios. In most cases, > objects are not going to be shared, and in those cases with > sufficiently complicated deployments in which shared objects > could be used, the user is likely to be sophisticated enough > and skilled enough to manage updating what are essentially > "copies" of objects, and would likely have an opinion about > how individual failures should be handled which wouldn't > necessarily coincide with what we developers of the system > would assume. That is to say, allowing too many many to many > relationships feels like a solution to a problem that doesn't > really exist, and introduces a lot of unnecessary complexity. > > > > > > In any case, though, I feel like we should walk before we run: > Implementing 1:1 initially is a good idea to get us rolling. > Whether we then implement 1:N or M:N after that is another > question entirely. But in any case, it seems like a bad idea > to try to start with M:N. > > > > > > Stephen > > > > > > > > On Thu, Nov 20, 2014 at 4:52 AM, Samuel Bercovici > <samu...@radware.com> wrote: > > Hi, > > Per discussion I had at OpenStack Summit/Paris with Brandon > and Doug, I would like to remind everyone why we choose to > follow a model where pools and listeners are shared (many to > many relationships). > > Use Cases: > 1. The same application is being exposed via different LB > objects. > For example: users coming from the internal "private" > organization network, have an LB1(private_VIP) --> > Listener1(TLS) -->Pool1 and user coming from the "internet", > have LB2(public_vip)-->Listener1(TLS)-->Pool1. > This may also happen to support ipv4 and ipv6: LB_v4(ipv4_VIP) > --> Listener1(TLS) -->Pool1 and LB_v6(ipv6_VIP) --> > Listener1(TLS) -->Pool1 > The operator would like to be able to manage the pool > membership in cases of updates and error in a single place. > > 2. The same group of servers is being used via different > listeners optionally also connected to different LB objects. > For example: users coming from the internal "private" > organization network, have an LB1(private_VIP) --> > Listener1(HTTP) -->Pool1 and user coming from the "internet", > have LB2(public_vip)-->Listener2(TLS)-->Pool1. > The LBs may use different flavors as LB2 needs TLS termination > and may prefer a different "stronger" flavor. > The operator would like to be able to manage the pool > membership in cases of updates and error in a single place. > > 3. The same group of servers is being used in several > different L7_Policies connected to a listener. Such listener > may be reused as in use case 1. > For example: LB1(VIP1)-->Listener_L7(TLS) > | > > +-->L7_Policy1(rules..)-->Pool1 > | > > +-->L7_Policy2(rules..)-->Pool2 > | > > +-->L7_Policy3(rules..)-->Pool1 > | > > +-->L7_Policy3(rules..)-->Reject > > > I think that the "key" issue handling correctly the > "provisioning" state and the operation state in a many to many > model. > This is an issue as we have attached status fields to each and > every object in the model. > A side effect of the above is that to understand the > "provisioning/operation" status one needs to check many > different objects. > > To remedy this, I would like to turn all objects besides the > LB to be logical objects. This means that the only place to > manage the status/state will be on the LB object. > Such status should be hierarchical so that logical object > attached to an LB, would have their status consumed out of the > LB object itself (in case of an error). > We also need to discuss how modifications of a logical object > will be "rendered" to the concrete LB objects. > You may want to revisit > > https://docs.google.com/document/d/1D-1n8nCEFurYzvEBxIRfXfffnImcIPwWSctAG-NXonY/edit#heading=h.3rvy5drl5b5r > the "Logical Model + Provisioning Status + Operation Status + Statistics" > for a somewhat more detailed explanation albeit it uses the LBaaS v1 model as > a reference. > > Regards, > -Sam. > > > > > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > > > > > -- > > Stephen Balukoff > Blue Box Group, LLC > (800)613-4305 x807 > > > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > > > -- > Stephen Balukoff > Blue Box Group, LLC > (800)613-4305 x807 > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev