[ovirt-users] Delay difference between queries (Python vs REST)

[Yaniv Kaul]

On Tue, Jan 17, 2017 at 6:03 PM, Juan Hernández <jhernand at redhat.com> wrote:

> On 01/17/2017 04:59 PM, Nicolas Ecarnot wrote:
> > Le 17/01/2017 à 16:26, Juan Hernández a écrit :
> >> On 01/17/2017 03:56 PM, Nicolas Ecarnot wrote:
> >>> Hello,
> >>>
> >>> On a 3.6.5 DC, I'm trying to figure out how many VMs there are, using
> >>> two methods :
> >>>
> >>> _*Python SDK :*_
> >>>
> >>> *from ovirtsdk.xml import params
> >>> from ovirtsdk.api import API
> >>> api = API(url='https://engine.fqdn/ovirt-engine/api',
> >>> username='admin at internal', password='xxx', insecure=True)
> >>> print len(api.vms.list())*
> >>>
> >>> time ./getMvm.py
> >>> 62
> >>>
> >>> real    0m23.016s
> >>> user    0m22.288s
> >>> sys    0m0.054s
> >>>
> >>>
> >>> _*REST :*_
> >>>
> >>> *time curl -H "Version: 3" -H "Prefer: persistent-auth" -H "Filter:
> >>> false" -H "Accept: application/xml" -H "Content-Type: application/xml"
> >>> -k -u 'admin at internal:xxx' https://***engine.fqdn*/ovirt-
> engine/api/vms*
> >>>
> >>> (Then grep or anything that would get the values from the xml
> returned.)
> >>>
> >>> real    0m0.383s
> >>> user    0m0.036s
> >>> sys    0m0.038s
> >>>
> >>>
> >>> I am a beginner in both methods, but I would prefer play with Python.
> >>> I'm very surprised to have to wait more than 20 seconds to get an
> >>> answer.
> >>> Looking at the engine log, I see that the authentication part is
> >>> finished after say 3 seconds, then 20 seconds with absolutely no error
> >>> message, no CPU load, no RAM burst, no nothing.
> >>> On the SPM, exactly triple null nothing nada niet void is obviously
> >>> explaining such a delay.
> >>>
> >>> I'm wondering if this super hyper sluggishness is somewhat related to
> >>> the GUI global slowness I'm experiencing like other users since we left
> >>> 3.2.x, and I would love that some oVirt ninja uses the comparison above
> >>> to tell what parts in oVirt is used or not that could explain such a
> >>> difference (database, access to SPM, LVM, network access, whatever...)
> >>>
> >>> --
> >>> Nicolas ECARNOT
> >>>
> >>
> >> The performance problem is inside version 3 of the Python SDK. That is
> >> one of the reasons that we had to do a new version of the Python SDK for
> >> version 4 of the engine. If you are using version 4 of the engine then
> >> you can use version 4 of the SDK:
> >>
> >>   https://github.com/oVirt/ovirt-engine-sdk/tree/master/sdk
> >>
> >> https://github.com/oVirt/ovirt-engine-sdk/blob/master/
> sdk/examples/list_vms.py
> >>
> >>
> >> It should be much faster. Would be nice if you can repeat your test and
> >> report the results.
> >>
> >
> > Hello Juan,
> >
> > Indeed, you were right. I tried the same from a recent server with a
> > recent SDK, and I let you have a look :
> >
> > # rpm -q python-ovirt-engine-sdk4
> > python-ovirt-engine-sdk4-4.0.1-1.el7.centos.x86_64
> >
> > # time ./getMvm.py
> > 62
> >
> > real    0m1.004s
> > user    0m0.234s
> > sys    0m0.031s
> >
> > And repeating the same test gives a very decent average, so thank you.
> >
>
> Twenty times faster, approx, good to know. Thanks. By the way, if you
> want even better performance, then make sure to disable debug and enable
> compression:
>
>   connection = sdk.Connection(
>     ...
>     debug=False,
>     compress=True,
>   )
>

Shouldn't it be the default?
Y.


>
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