[Spice-devel] spice performance tweaking

Thu Sep 15 14:54:21 UTC 2016

Hi,

I tried a virtual rhel7.3beta (server with gui) on a rhel7.3beta host.

The host was a laptop to which I setup to use my old wifi router that only
has 54Mbit so the bandwith was poor and unstable.

Without the compression options the spice display was really bad.
You could see the screen being rendered bit by bit.

I tried this with the custom rpm and did not really see an improvement.

I downgraded the spice-server and rebooted

I added the compression options:
      <image compression='glz'/>
      <jpeg compression='always'/>
      <zlib compression='always'/>
      <streaming mode='all'/>

Now the spice display was very usable and almost no artifacts.

Only when moving the windows you can see tearing at the edges.
Also started a glxgears window to see how it deals with that

I applied the custom rpm and rebooted the host.

After restarting the vm and logging into spice
There is less tearing when moving the window.

So there is an improvement, but it's hard to tell how much  by simply
watching when draging the window.

some details from our openvpn config
the protocol has to be tcp.....

centos 7.2 openvpn server settings:

port secret-port-number
proto tcp
dev tun
tun-mtu 1500
ca /path/to/ca
cert /path/to/cert
key /path/to/key
dh /path/to/dh
server some.ip.address some.subnet.mask
ifconfig-pool-persist ipp.txt
keepalive 10 120
comp-lzo
user nobody
group nobody
persist-key
persist-tun
status /path/to/log
verb 3
mute 20

fedora 24 NetworkManager settings:
[connection]
id=our id for our top secret vpn
uuid=xxxxxxxx.xxxx.xxx.xxx.xx
type=vpn
permissions=user:secretusernottellingyou:;
secondaries=

[vpn]
remote-random=no
connection-type=tls
remote=remote.ip.address
tunnel-mtu=1500
comp-lzo=yes
cert-pass-flags=1
proto-tcp=yes
port=<secret-port>
mssfix=yes
dev-type=tun
ca=/path/to/ca
key=/path/to/key
cert=/path/to/crt
service-type=org.freedesktop.NetworkManager.openvpn

[ipv4]
dns-search=
ignore-auto-routes=true
method=auto
never-default=true

route1=additional.route/mask

route2=additional.route/mask

[ipv6]

addr-gen-mode=stable-privacy

dns-search=

method=auto

Cheers
Rob Verduijn.

2016-09-15 16:04 GMT+02:00 Rob Verduijn <rob.verduijn at gmail.com>:

> Hello,
>
> The performance fixes sound awesome.
> I'm afraid I cannot test them in the environment with the low bandwith
> setup soon (maybe next week, but don't hold your breath)
> I'm going to build a local test setup to see if this is improving some of
> the issues. I got a laptop running the rhel7.3 beta, let's see how that
> performs.
>
> Rob Verduijn
>
>
> 2016-09-15 13:31 GMT+02:00 Frediano Ziglio <fziglio at redhat.com>:
>
>> I saw you are using CentOS 7. I built the package with RHEL 7 (they are
>> binary compatible).
>> About the testing just which normal usage you should see improvements in
>> bandwidth and
>> reactivity.
>>
>> Changes from current CentOS package:
>> - used a newer version, there are couple of changes that decrease latency;
>> - additional patches to improve bandwidth usage (for small drawing this
>> should decrease
>>   bandwidth usage by a 15-20%);
>> - additional patch to decrease a bandwidth limitation due to a peculiar
>> half-duplex usage
>>   of spice protocol (this is clearly visible with high latency
>> connections);
>> - additional patch to decrease packet fragmentation due to TCP_NODELAY
>> usage.
>>
>> Alternatively would be helpful for us to get a local reproduction of the
>> problem.
>> OpenVPN configuration files would be helpful (we don't need any security
>> detail like keys, ip, host or system names, just to understand the type
>> of VPN,
>> encryption parameters, compression, additional latency introduced and so
>> on).
>>
>> The fact that you are not able to get a record from the guest means that
>> the QXL
>> (guest <-> server) protocol how the spice-server is handling guest
>> command is
>> fine. The fact that on the client you can see clearly such slowness is
>> due to spice
>> protocol, the connection/vpn, some spice-server implementation and
>> possibly
>> client implementation too. Unfortunately too much stuff to be able to
>> point the
>> finger to one of them.
>> I tried some test and did this:
>> - opened task manager on Windows 7;
>> - switched to performance tab;
>> - maximized task manager;
>> - double clicked on CPU usage to get only CPU usage and history.
>> When CPU usage change I can see the flickering on CPU usage but not on
>> the history graphs. It this the kind of flickering you are noticing?
>>
>> Frediano
>>
>>
>> For which distro is that package ?
>> Centos 7.2 ? rhel7.3beta or fedora24 ?
>>
>> Rob Verduijn
>>
>> 2016-09-14 15:59 GMT+02:00 Frediano Ziglio <fziglio at redhat.com>:
>>
>>> Could you test at least? Would be very helpful. We could then backport
>>> some improvements.
>>>
>>> Frediano
>>>
>>>
>>> thanx,I'll stick with the centos packages,
>>>
>>> I need a very good reason before I start using beta packages.
>>> And a nice to have feature is not one of them.
>>>
>>> Also I dug in to the openvpn tweaks and it seems that all of them are
>>> related to udp tunnels.
>>> Performance is sadly rather low when you have to use tcp (like me)
>>> because the firewall is managed by a third party.
>>>
>>> Rob Verduijn
>>>
>>> 2016-09-14 15:49 GMT+02:00 Frediano Ziglio <fziglio at redhat.com>:
>>>
>>>>
>>>> Hello,
>>>>
>>>> I'm trying to improve my spice performance on a kvm host/guest.
>>>> It's currently rather slow and I can see screens beeing build up, and
>>>> delays when draging windows.
>>>>
>>>> It's being tunneled through openvpn, which is set to use tcp.
>>>> tcp required because of the firewall which is maintained by 3rd party.
>>>>
>>>> I have full access to the kvm host, kvm guest and openvpn server.
>>>>
>>>> Have you got any tips so that I can improve spice performance ?
>>>> I alrready am running tuned with the virtual-guest profile for  guests
>>>> and host profile for the host.
>>>> All systems are runnning CentOS 7
>>>>
>>>> Any tips for :
>>>> - the KVM host ?
>>>> - the KVM guest ?
>>>> - the openvpn server ?
>>>>
>>>> Cheers
>>>> Rob Verduijn
>>>>
>>>> Hi,
>>>>   can you try version at https://www.datafilehost.com/d/b07f008e ?
>>>>
>>>> The sha1 hash (please check it) is 0e2191c363e109475aeb2bff401e69
>>>> 9f0a07a795.
>>>>
>>>> Be prepare for the rollback, it's not a version meant for production
>>>> usage.
>>>>
>>>> Frediano
>>>>
>>>>
>>>
>>>
>>
>>
>
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