[ovirt-users] ovirt-ha-agent cpu usage

[Simone Tiraboschi]

On Fri, Oct 7, 2016 at 4:02 PM, Michal Skrivanek <
michal.skrivanek at redhat.com> wrote:

>
> On 7 Oct 2016, at 15:28, Simone Tiraboschi <stirabos at redhat.com> wrote:
>
>
>
> On Fri, Oct 7, 2016 at 3:25 PM, Michal Skrivanek <
> michal.skrivanek at redhat.com> wrote:
>
>>
>> On 7 Oct 2016, at 14:59, Nir Soffer <nsoffer at redhat.com> wrote:
>>
>> On Fri, Oct 7, 2016 at 3:52 PM, Michal Skrivanek <
>> michal.skrivanek at redhat.com> wrote:
>>
>>>
>>> On 7 Oct 2016, at 14:42, Nir Soffer <nsoffer at redhat.com> wrote:
>>>
>>> On Wed, Oct 5, 2016 at 1:33 PM, Simone Tiraboschi <stirabos at redhat.com>
>>> wrote:
>>>
>>>>
>>>>
>>>> On Wed, Oct 5, 2016 at 10:34 AM, Nir Soffer <nsoffer at redhat.com> wrote:
>>>>
>>>>> On Wed, Oct 5, 2016 at 10:24 AM, Simone Tiraboschi <
>>>>> stirabos at redhat.com> wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> On Wed, Oct 5, 2016 at 9:17 AM, gregor <gregor_forum at catrix.at>
>>>>>> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> did you found a solution or cause for this high CPU usage?
>>>>>>> I have installed the self hosted engine on another server and there
>>>>>>> is
>>>>>>> no VM running but ovirt-ha-agent uses heavily the CPU.
>>>>>>>
>>>>>>
>>>>>> Yes, it's due to the fact that ovirt-ha-agent periodically reconnects
>>>>>> over json rpc and this is CPU intensive since the client has to parse the
>>>>>> yaml API specification each time it connects.
>>>>>>
>>>>>
>>> wasn’t it suppose to be fixed to reuse the connection? Like all the
>>> other clients (vdsm migration code:-)
>>>
>>
>> This is orthogonal issue.
>>
>>
>> Yes it is. And that’s the issue;-)
>> Both are wrong, but by “fixing” the schema validation only you lose the
>> motivation to fix the meaningless wasteful reconnect
>>
>
> Yes, we are going to fix that too ( https://bugzilla.redhat.com/
> show_bug.cgi?id=1349829 )
>
>
> that’s great! Also al the other vdsClient uses?:-)
>

https://gerrit.ovirt.org/#/c/62729/


> What is that periodic one call anyway? Is there only one? Maybe we don’t
> need it so much.
>

Currently ovirt-ha-agent is periodically reconnecting the hosted-engine
storage domain and checking its status. This is already on jsonrpc.
In 4.1 all the monitoring will be moved to jsonrpc.


>
> but it would require also https://bugzilla.redhat.com/
> show_bug.cgi?id=1376843 to be fixed.
>
>
> This is less good. Well, worst case you can reconnect yourself, all you
> need is a notification when the existing connection breaks
>
>
>
>>
>>
>>
>>> Does schema validation matter then if there would be only one connection
>>> at the start up?
>>>
>>
>> Loading once does not help command line tools like vdsClient,
>> hosted-engine and
>> vdsm-tool.
>>
>>
>> none of the other tools is using json-rpc.
>>
>
> hosted-engine-setup is, and sooner or later we'll have to migrate also the
> remaining tools since xmlrpc has been deprecated with 4.0
>
>
> ok. though setup is a one-time action so it’s not an issue there
>
>
>
>>
>>
>> Nir
>>
>>
>>>
>>>
>>>>> Simone, reusing the connection is good idea anyway, but what you
>>>>> describe is
>>>>> a bug in the client library. The library does *not* need to load and
>>>>> parse the
>>>>> schema at all for sending requests to vdsm.
>>>>>
>>>>> The schema is only needed if you want to verify request parameters,
>>>>> or provide online help, these are not needed in a client library.
>>>>>
>>>>> Please file an infra bug about it.
>>>>>
>>>>
>>>> Done, https://bugzilla.redhat.com/show_bug.cgi?id=1381899
>>>>
>>>
>>> Here is a patch that should eliminate most most of the problem:
>>> https://gerrit.ovirt.org/65230
>>>
>>> Would be nice if it can be tested on the system showing this problem.
>>>
>>> Cheers,
>>> Nir
>>> _______________________________________________
>>> Users mailing list
>>> Users at ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>>>
>>>
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