[ovirt-devel] Killing XMLRPC on master

[Martin Sivak]

> If we subscribe to engine response queue we receive all the traffic. At the
> moment there is no way
> to define verbs we listen to. This functionality is only for events.

Can't we create a new topic /engine/<verb> for each verb and configure
vdsm to listen for /engine/*? That would duplicate what we have now,
but MOM would be able to subscribe more selectively.

Martin


On Wed, Jun 22, 2016 at 11:24 AM, Piotr Kliczewski <pkliczew at redhat.com> wrote:
>
>
> On Wed, Jun 22, 2016 at 10:39 AM, Michal Skrivanek
> <michal.skrivanek at redhat.com> wrote:
>>
>>
>> On 20 Jun 2016, at 18:41, Piotr Kliczewski <pkliczew at redhat.com> wrote:
>>
>>
>>
>> On Mon, Jun 20, 2016 at 6:22 PM, Nir Soffer <nsoffer at redhat.com> wrote:
>>>
>>> On Mon, Jun 20, 2016 at 11:33 AM, Martin Sivak <msivak at redhat.com> wrote:
>>> >> 1. Mom is still using xmlrpc
>>> >>
>>> >> Mom must move to jsonrpc.
>>> >> Martin: can you update on progress of this work?
>>> >
>>> > We would like to avoid going through VDSM completely, except from the
>>> > broker part. Is it possible now to "parasitically" listen to vdsm
>>> > events and engine commands without having to go through VDSM API?
>>>
>>> Sounds like a good plan.
>>
>>
>> bypassing vdsm for mom things is a good idea, but we need to make sure
>> we’re not killing the rest of the system
>>
>>>
>>> Piotr, how far are we from letting mom listen to engine queue so it get
>>> engine
>>> events/responses for certain verbs?
>>
>>
>> We can do it now for both events and responses. We need to remember that
>> we would
>> receive anything that the engine is receiving. We could do better but that
>> it would take
>> more time.
>>
>>
>> so it would receive all responses for only the defined verbs?
>> It would wok well for getAllVmStats
>>
>
> If we subscribe to engine response queue we receive all the traffic. At the
> moment there is no way
> to define verbs we listen to. This functionality is only for events.
>
>>
>>
>>>
>>>
>>> > You can drop XML RPC,. vdsm does not depend on MOM working anymore.
>>> > Just the balloon and ksm stats will be missing from data that are
>>> > being sent to the engine.
>>
>>
>> and a lot of things stops working then;)
>>
>
> Maybe we can disable [1] it before dropping it. We can slowly fix master and
> if needed we can enable it for
> specific envs.
>
> [1] https://gerrit.ovirt.org/#/c/59172/
>>>
>>>
>>> Balloon and ksm stats are sent today from mom to vdsm, and reported by
>>> vdsm to engine?
>>>
>>> If vdsm is only a middleman  and does not use this info, best to send
>>> it directly
>>> to engine via the stomp broker part of vdsm.
>>>
>>> Piotr, how far are we from having engine listening for mom events using
>>> the
>>> vdsm broker?
>>
>>
>> I don’t think we should move any monitoring pulled from libvirt into mom -
>> it would need another expensive and problematic call
>>
>>
>> It can be used now but the engine needs to know to listen for them. We
>> would
>> need to implement engine subscriber (one class).
>>
>>>
>>>
>>> > There also were some issues with eventfd in the json library, I assume
>>> > those are fixed now.
>>>
>>> They should be fixed here:
>>> https://gerrit.ovirt.org/57942
>>>
>>> But suffering from these issue show that the api was not use properly,
>>> you should create one client and reuse it for the entire life of the
>>> application.
>>>
>>>
>>> Nir
>>>
>>> >
>>> > Martin
>>> >
>>> > On Sun, Jun 19, 2016 at 1:02 PM, Nir Soffer <nsoffer at redhat.com> wrote:
>>> >> Hi all,
>>> >>
>>> >> We are still wasting time on maintaining both xmlrpc and jsonrpc. If
>>> >> we kill
>>> >> xmlrpc, we can greatly simplify the code base, making it easier to
>>> >> mainain
>>> >> and add new features.
>>> >>
>>> >> I suggest to kill xmlrpc in 4.1, and disable it *now* on master.
>>> >>
>>> >> Currently the we have 3 issues:
>>> >>
>>> >> 1. Mom is still using xmlrpc
>>> >>
>>> >> Mom must move to jsonrpc.
>>> >> Martin: can you update on progress of this work?
>>> >>
>>> >> 2. sos plugin using vdsClient
>>> >>
>>> >> Need to port it to use jsonrpc library, or jsonrpc client
>>> >>
>>> >> New jsonrpc client:  https://gerrit.ovirt.org/35181
>>> >>
>>> >> 3. Engine is using xmlrpc server for ovf upload/download
>>> >>
>>> >> We must support current engine in 4.1, so we cannot remove
>>> >> upload/download feature in this version, but we can remove the
>>> >> xmlrpc support in this server.
>>> >>
>>> >> Currently we abuse the xmlrpc server, supporting PUT and GET for
>>> >> upload and download (XMLRPC is using only POST). We can disable
>>> >> POST requests in protocoldetector, and not register anything with
>>> >> the xmlrpc server.
>>> >>
>>> >> Thoughts?
>>> >>
>>> >> Nir
>>
>>
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>