[Freeswitch-users] KVM vs. XEN virtualization
Giovanni Maruzzelli
gmaruzz at gmail.com
Mon Apr 6 21:09:09 MSD 2015
sent from my mobile,
Giovanni Maruzzelli
cell: +39 347 266 56 18
On Apr 6, 2015 5:31 PM, "Anthony Minessale" <anthony.minessale at gmail.com>
wrote:
>
> Depending on the host and guest OS the timing will be a product of
several thing.
> If some of the features FS tries to detect are emulated, it can be a
problem.
>
> The primary thing FS looks for is a kernel with timerfd support.
> This should be the most accurate. If the guest OS supports timerfd but
its using emulated hardware, it might not work as well as it should.
>
> So on something like openvz, you might have support for timerfd in your
debian 7/8 instance but the host kernel has no support at all.
Tony, in my understanding in OpenVZ you have one only kernel, and true
timerfd.
Each OpenVZ "container" is just a glorified jail, no emulation at all. A
kernel namespace. But processes run directly on real kernel, real IRQs,
real timerfd.
Seems to me I never heard of FreeSWITCH problems with OpenVZ.
Please correct me if I'm wrong.
-giovanni
> So in theory kvm would be preferred since it actually boots the guest
kernel and you have a chance for it to hit the real timer hardware.
>
> If no timerfd is present, it reverts to the single thread ms precision
thread with conditional broadcast for timing.
> You can also manually configure a combo of one timerfd timer and shared
broadcast.
>
> This param in switch.conf.xml helps to tune a few behavior you might want
to compare results on.
>
> enable-softtimer-timerfd
>
> true|fd-per-timer --- Use one fd for each timer instance (default)
>
> false --- Don't use timerfd at all
>
> broadcast --- Use one timerfd and share it with conditional
broadcasts
>
> This is one reason we do not support virtualization as its too variable
to provide definitive policies to make things work every time.
>
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>
> On Mon, Apr 6, 2015 at 10:17 AM, Stanislav Sinyagin <ssinyagin at gmail.com>
wrote:
>>
>> I didn't yet have time to learn this utility - how do we interpret the
results?
>>
>> On Apr 6, 2015 4:39 PM, "Errol Samuels" <ewsamuels at gmail.com> wrote:
>>>
>>> Ok Sergey,
>>>
>>> Here it goes:
>>>
>>> Test 1
>>> ====
>>> VM: Digital Ocean KVM at AMS3 / 2 Cores / 2GB Ram / 40GB SSD
>>> OS: Debian Wheezy 7.8 64 bit / Linux 3.2.0-4-amd64 x86_64
>>>
>>> policy: fifo: loadavg: 6.22 1.53 0.58 1/164 31050 : 195
Max: 42869
>>> T:12 (31021) P:80 I:125 C: 238830 Min: 2 Act: 18 Avg: 196
Max: 42846
>>> T: 0 (31009) P:80 I:125 C: 239000 Min: 2 Act: 12 Avg: 190
Max: 42845
>>> T: 1 (31010) P:80 I:125 C: 239002 Min: 2 Act: 18 Avg: 196
Max: 42866
>>> T: 2 (31011) P:80 I:125 C: 239004 Min: 3 Act: 10 Avg: 191
Max: 42890
>>> T: 3 (31012) P:80 I:125 C: 239004 Min: 3 Act: 8 Avg: 197
Max: 42876
>>> T: 4 (31013) P:80 I:125 C: 239005 Min: 2 Act: 27 Avg: 194
Max: 42846
>>> T: 5 (31014) P:80 I:125 C: 239008 Min: 2 Act: 26 Avg: 196
Max: 42872
>>> T: 6 (31015) P:80 I:125 C: 239013 Min: 2 Act: 12 Avg: 196
Max: 42843
>>> T: 7 (31016) P:80 I:125 C: 239013 Min: 2 Act: 19 Avg: 194
Max: 42848
>>> T: 8 (31017) P:80 I:125 C: 239013 Min: 2 Act: 14 Avg: 190
Max: 42856
>>> T: 9 (31018) P:80 I:125 C: 239014 Min: 2 Act: 14 Avg: 197
Max: 42865
>>> T:10 (31019) P:80 I:125 C: 239016 Min: 2 Act: 9 Avg: 197
Max: 42868
>>>
>>>
>>> Test 2
>>> ====
>>> VM: Linode (Xen) London / 8 Cores (E5-2670 0 @ 2.60GHz) / 4GB Ram
>>> OS: Ubuntu 12.04.4 LTS / Linux 3.18.5-x86_64-linode52 x86_64
>>>
>>> policy: fifo: loadavg: 6.50 1.56 0.55 15/246 30752 97
Max: 1030
>>> T:16 (30726) P:80 I:125 C: 239853 Min: 5 Act: 77 Avg: 97
Max: 1066
>>> T: 0 (30710) P:80 I:125 C: 239946 Min: 5 Act: 63 Avg: 98
Max: 1245
>>> T: 1 (30711) P:80 I:125 C: 239946 Min: 5 Act: 67 Avg: 98
Max: 1091
>>> T: 2 (30712) P:80 I:125 C: 239945 Min: 5 Act: 119 Avg: 97
Max: 1351
>>> T: 3 (30713) P:80 I:125 C: 239945 Min: 5 Act: 99 Avg: 98
Max: 932
>>> T: 4 (30714) P:80 I:125 C: 239945 Min: 5 Act: 35 Avg: 98
Max: 1413
>>> T: 5 (30715) P:80 I:125 C: 239945 Min: 5 Act: 35 Avg: 98
Max: 1407
>>> T: 6 (30716) P:80 I:125 C: 239944 Min: 5 Act: 110 Avg: 97
Max: 1173
>>> T: 7 (30717) P:80 I:125 C: 239947 Min: 5 Act: 85 Avg: 99
Max: 1144
>>> T: 8 (30718) P:80 I:125 C: 239948 Min: 4 Act: 69 Avg: 99
Max: 916
>>> T: 9 (30719) P:80 I:125 C: 239947 Min: 4 Act: 40 Avg: 97
Max: 916
>>> T:10 (30720) P:80 I:125 C: 239948 Min: 5 Act: 61 Avg: 97
Max: 1024
>>> T:11 (30721) P:80 I:125 C: 239946 Min: 6 Act: 84 Avg: 98
Max: 2082
>>> T:12 (30722) P:80 I:125 C: 239947 Min: 4 Act: 40 Avg: 98
Max: 2142
>>> T:13 (30723) P:80 I:125 C: 239946 Min: 5 Act: 49 Avg: 98
Max: 1986
>>> T:14 (30724) P:80 I:125 C: 239946 Min: 4 Act: 113 Avg: 99
Max: 2061
>>>
>>> This is with system defaults.
>>>
>>> regards,
>>>
>>> Errol
>>>
>>>
>>>
>>>
>>> On Mon, Apr 6, 2015 at 1:27 PM, Sergey Safarov <s.safarov at gmail.com>
wrote:
>>>>
>>>> Errol can you test VM timer with utility
https://rt.wiki.kernel.org/index.php/Cyclictest
>>>>
>>>> My VM currently have folowing results
>>>>
>>>> [root at fs1 ~]# date && /tmp/rt-tests/cyclictest -t42 -p 80 -d 0 -n -i
125 -l 240000 && date
>>>> Sun Apr 5 07:01:31 GMT 2015
>>>> # /dev/cpu_dma_latency set to 0us
>>>> policy: fifo: loadavg: 2.38 0.93 0.50 1/194 1574
>>>>
>>>> T: 0 ( 1531) P:80 I:125 C: 240000 Min: 2 Act: 12 Avg: 16
Max: 1302
>>>> T: 1 ( 1532) P:80 I:125 C: 240000 Min: 2 Act: 15 Avg: 14
Max: 2895
>>>> T: 2 ( 1533) P:80 I:125 C: 240000 Min: 3 Act: 10 Avg: 12
Max: 2888
>>>> T: 3 ( 1534) P:80 I:125 C: 240000 Min: 1 Act: 16 Avg: 13
Max: 1333
>>>> T: 4 ( 1535) P:80 I:125 C: 240000 Min: 2 Act: 20 Avg: 14
Max: 2962
>>>> T: 5 ( 1536) P:80 I:125 C: 240000 Min: 1 Act: 12 Avg: 14
Max: 2946
>>>> T: 6 ( 1537) P:80 I:125 C: 240000 Min: 2 Act: 10 Avg: 13
Max: 1363
>>>> T: 7 ( 1538) P:80 I:125 C: 240000 Min: 2 Act: 12 Avg: 13
Max: 1344
>>>> T: 8 ( 1539) P:80 I:125 C: 240000 Min: 3 Act: 12 Avg: 16
Max: 1408
>>>> T: 9 ( 1540) P:80 I:125 C: 240000 Min: 1 Act: 8 Avg: 13
Max: 2882
>>>> T:10 ( 1541) P:80 I:125 C: 239974 Min: 2 Act: 12 Avg: 13
Max: 2908
>>>>
>>>>
>>>> On Mon, Apr 6, 2015 at 11:15 AM, Errol Samuels <ewsamuels at gmail.com>
wrote:
>>>>>
>>>>> Good job and Thanks for sharing!
>>>>>
>>>>>> KVM at digitalocean.com, Debian 7 64bit, FreeSWITCH 1.4.15: bad
precision
>>>>>
>>>>>
>>>>> As someone who has been using KVM for a few years and has just
migrated about 20 VMs across to Digital Ocean about 6 weeks ago I admit I
am a little concerned about this finding.
>>>>>
>>>>> Just out of curiosity can you tell me the specs of the VM that you
tested with and which DO Datacenter? I am using NYC3 so perhaps and I will
do some tests as soon as I have some time.
>>>>>
>>>>> With regards to Xen was this at Linode or inhouse?
>>>>>
>>>>> Thanks
>>>>>
>>>>> Errol
>>>>>
>>>>>
>>>>>
>>>>> On Sun, Apr 5, 2015 at 1:37 AM, Stanislav Sinyagin <
ssinyagin at gmail.com> wrote:
>>>>>>
>>>>>> here we go:
>>>>>>
https://txlab.wordpress.com/2015/04/05/testing-rtp-clock-precision-on-a-virtual-machine/
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Sat, Apr 4, 2015 at 4:26 PM, Stanislav Sinyagin <
ssinyagin at gmail.com> wrote:
>>>>>> > On Sat, Apr 4, 2015 at 1:03 PM, Regis M <
regis.freeswitch.org at tornad.net> wrote:
>>>>>> >> How do you check wavs together in audacity ?
>>>>>> >
>>>>>> > you just open two WAV files, align their starting position, and
>>>>>> > visually check the waves. If there's a problem, you would see that
>>>>>> > after few seconds, the waves are not aligned any more.
>>>>>> >
>>>>>> >> Can you send me 2 samples wav (send... and recorded) so I could
see the 20ms
>>>>>> >> diff that you exposed...
>>>>>> >>
>>>>>> >> Is there a way to automate the result checking, so it could help
to monitor
>>>>>> >> itsp quality
>>>>>> >
>>>>>> > Here
>>>>>> > https://github.com/openpreserve/scape-xcorrsound/issues/17
>>>>>> > this is a link to a tool which compares two sound files at the wave
>>>>>> > level. You can also see the sound samples in the ticket.
>>>>>> > The problem is, that currently this tool does not detect such
slipping frames.
>>>>>> >
>>>>>> > I will also write a detailed article with examples, during the
weekend.
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>> >>
>>>>>> >>
>>>>>> >> 2015-04-04 12:53 GMT+02:00 Stanislav Sinyagin <ssinyagin at gmail.com
>:
>>>>>> >>>
>>>>>> >>> Important is to send the media through two independent carriers
- then you
>>>>>> >>> can be sure that your clock is compared against a high quality
one.
>>>>>> >>>
>>>>>> >>> On Apr 4, 2015 12:46 PM, "Regis M" <
regis.freeswitch.org at tornad.net>
>>>>>> >>> wrote:
>>>>>> >>>>
>>>>>> >>>> Hi,
>>>>>> >>>>
>>>>>> >>>> It's a very interresting test and conclusion.
>>>>>> >>>>
>>>>>> >>>> I will try to build a similar environnement on my freeswitch to
check
>>>>>> >>>> some system :)
>>>>>> >>>>
>>>>>> >>>> thanks
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>> 2015-04-04 2:16 GMT+02:00 Stanislav Sinyagin <
ssinyagin at gmail.com>:
>>>>>> >>>>>
>>>>>> >>>>> hi,
>>>>>> >>>>>
>>>>>> >>>>> Here are some test results which might be interesting:
>>>>>> >>>>>
>>>>>> >>>>> I've set up a test FreeSWITCH server at digitalocean (they use
KVM),
>>>>>> >>>>> and originated test calls to some ITSP accounts. Each call
played a
>>>>>> >>>>> test sound file (voice samples from ITU:
>>>>>> >>>>>
http://www.itu.int/net/itu-t/sigdb/genaudio/AudioForm-g.aspx?val=1000050
>>>>>> >>>>> ), and on the receiving end another FreeSWITCH server was
recording
>>>>>> >>>>> the received session. The receiving server was on a XEN VM.
Both
>>>>>> >>>>> servers talked G711 to their corresponding ITSP accounts.
>>>>>> >>>>>
>>>>>> >>>>> Then I compared the source audio and received audio in
Audacity editor.
>>>>>> >>>>>
>>>>>> >>>>> The tests showed that the received voice wave shifts 20ms from
the
>>>>>> >>>>> original sound every few seconds, randomly back and forward.
This
>>>>>> >>>>> skewing was always present, regardless of ITSP and time of day.
>>>>>> >>>>>
>>>>>> >>>>> Then I moved the sending server to a XEN VM, and the waves
appeared
>>>>>> >>>>> almost perfectly synchronized (there was a 5ms skew in one
test, and I
>>>>>> >>>>> guess it's related to transcoding buffer, as the sound was
obviously
>>>>>> >>>>> transcoded).
>>>>>> >>>>>
>>>>>> >>>>> The effect was always visible with a 30-second sample, and I
also made
>>>>>> >>>>> additional tests with 2-minute samples.
>>>>>> >>>>>
>>>>>> >>>>> It would also be interesting to test this from a VmWare VM. If
someone
>>>>>> >>>>> wants to run such a test, feel free to contact me directly.
>>>>>> >>>>>
>>>>>> >>>>>
>>>>>> >>>>> cheers,
>>>>>> >>>>> stan
>>>>>> >>>>>
>>>>>> >>>>>
>>>>>> >>>>>
_________________________________________________________________________
>>>>>> >>>>> Professional FreeSWITCH Consulting Services:
>>>>>> >>>>> consulting at freeswitch.org
>>>>>> >>>>> http://www.freeswitchsolutions.com
>>>>>> >>>>>
>>>>>> >>>>> Official FreeSWITCH Sites
>>>>>> >>>>> http://www.freeswitch.org
>>>>>> >>>>> http://confluence.freeswitch.org
>>>>>> >>>>> http://www.cluecon.com
>>>>>> >>>>>
>>>>>> >>>>> FreeSWITCH-users mailing list
>>>>>> >>>>> FreeSWITCH-users at lists.freeswitch.org
>>>>>> >>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>>>>> >>>>> UNSUBSCRIBE:
http://lists.freeswitch.org/mailman/options/freeswitch-users
>>>>>> >>>>> http://www.freeswitch.org
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>>
_________________________________________________________________________
>>>>>> >>>> Professional FreeSWITCH Consulting Services:
>>>>>> >>>> consulting at freeswitch.org
>>>>>> >>>> http://www.freeswitchsolutions.com
>>>>>> >>>>
>>>>>> >>>> Official FreeSWITCH Sites
>>>>>> >>>> http://www.freeswitch.org
>>>>>> >>>> http://confluence.freeswitch.org
>>>>>> >>>> http://www.cluecon.com
>>>>>> >>>>
>>>>>> >>>> FreeSWITCH-users mailing list
>>>>>> >>>> FreeSWITCH-users at lists.freeswitch.org
>>>>>> >>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>>>>> >>>> UNSUBSCRIBE:
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>>>>>> >>>> http://www.freeswitch.org
>>>>>> >>>
>>>>>> >>>
>>>>>> >>>
_________________________________________________________________________
>>>>>> >>> Professional FreeSWITCH Consulting Services:
>>>>>> >>> consulting at freeswitch.org
>>>>>> >>> http://www.freeswitchsolutions.com
>>>>>> >>>
>>>>>> >>> Official FreeSWITCH Sites
>>>>>> >>> http://www.freeswitch.org
>>>>>> >>> http://confluence.freeswitch.org
>>>>>> >>> http://www.cluecon.com
>>>>>> >>>
>>>>>> >>> FreeSWITCH-users mailing list
>>>>>> >>> FreeSWITCH-users at lists.freeswitch.org
>>>>>> >>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>>>>> >>> UNSUBSCRIBE:
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>>>>>> >>> http://www.freeswitch.org
>>>>>> >>
>>>>>> >>
>>>>>> >>
>>>>>> >>
_________________________________________________________________________
>>>>>> >> Professional FreeSWITCH Consulting Services:
>>>>>> >> consulting at freeswitch.org
>>>>>> >> http://www.freeswitchsolutions.com
>>>>>> >>
>>>>>> >> Official FreeSWITCH Sites
>>>>>> >> http://www.freeswitch.org
>>>>>> >> http://confluence.freeswitch.org
>>>>>> >> http://www.cluecon.com
>>>>>> >>
>>>>>> >> FreeSWITCH-users mailing list
>>>>>> >> FreeSWITCH-users at lists.freeswitch.org
>>>>>> >> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>>>>> >> UNSUBSCRIBE:
http://lists.freeswitch.org/mailman/options/freeswitch-users
>>>>>> >> http://www.freeswitch.org
>>>>>>
>>>>>>
_________________________________________________________________________
>>>>>> Professional FreeSWITCH Consulting Services:
>>>>>> consulting at freeswitch.org
>>>>>> http://www.freeswitchsolutions.com
>>>>>>
>>>>>> Official FreeSWITCH Sites
>>>>>> http://www.freeswitch.org
>>>>>> http://confluence.freeswitch.org
>>>>>> http://www.cluecon.com
>>>>>>
>>>>>> FreeSWITCH-users mailing list
>>>>>> FreeSWITCH-users at lists.freeswitch.org
>>>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>>>>> UNSUBSCRIBE:
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>>>>>> http://www.freeswitch.org
>>>>>
>>>>>
>>>>>
>>>>>
_________________________________________________________________________
>>>>> Professional FreeSWITCH Consulting Services:
>>>>> consulting at freeswitch.org
>>>>> http://www.freeswitchsolutions.com
>>>>>
>>>>> Official FreeSWITCH Sites
>>>>> http://www.freeswitch.org
>>>>> http://confluence.freeswitch.org
>>>>> http://www.cluecon.com
>>>>>
>>>>> FreeSWITCH-users mailing list
>>>>> FreeSWITCH-users at lists.freeswitch.org
>>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>>>> UNSUBSCRIBE:
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>>>>> http://www.freeswitch.org
>>>>
>>>>
>>>>
>>>>
_________________________________________________________________________
>>>> Professional FreeSWITCH Consulting Services:
>>>> consulting at freeswitch.org
>>>> http://www.freeswitchsolutions.com
>>>>
>>>> Official FreeSWITCH Sites
>>>> http://www.freeswitch.org
>>>> http://confluence.freeswitch.org
>>>> http://www.cluecon.com
>>>>
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>>>
>>>
>>>
>>>
_________________________________________________________________________
>>> Professional FreeSWITCH Consulting Services:
>>> consulting at freeswitch.org
>>> http://www.freeswitchsolutions.com
>>>
>>> Official FreeSWITCH Sites
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>>> http://confluence.freeswitch.org
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>>>
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>>
>>
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting at freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://confluence.freeswitch.org
>> http://www.cluecon.com
>>
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>
>
>
>
> --
> Anthony Minessale II ♬ @anthmfs ♬ @FreeSWITCH ♬
>
> ☞ http://freeswitch.org/ ☞ http://cluecon.com/ ☞
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>
> _________________________________________________________________________
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> http://www.freeswitchsolutions.com
>
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