tinc - Oct 2011 - Tinc CPU usage

Hi, I'm using Tinc v1.0.11 on Ubuntu 10.04 and seeing high CPU usage (up 
to 30%) on what I wouldn't consider high traffic levels.

The traffic is application server to database server connections and 
multicast communication for session-replication on the application server.

I'm running the tinc daemons in switch mode, to support the multicast. I 
have tried settings:

TunnelServer = no
Forwarding = off
DirectOnly = yes

To see whether that has an effect on CPU usage; which I haven't 
confirmed yet.

There aren't any special settings per host, just the address and the key.

1.0.11 is the latest package of Tinc I can find for Ubuntu 10.04; is it 
worth me trying to build or find a package for 1.0.16? I read the 
changes and it didn't appear that there were performance improvements 
for my case.

Any other tips for performance tuning Tinc?

Best regards,
Karl

On Thu, Oct 27, 2011 at 10:34:21AM +1300, Karl von Randow wrote:
> Hi, I'm using Tinc v1.0.11 on Ubuntu 10.04 and seeing high CPU usage
> (up to 30%) on what I wouldn't consider high traffic levels.
It all depends on how much traffic and what kind of CPU you have. Can you give
some numbers?
> I'm running the tinc daemons in switch mode, to support the
> multicast. I have tried settings:
> 
> TunnelServer = no
> Forwarding = off
> DirectOnly = yes
> 
> To see whether that has an effect on CPU usage; which I haven't
> confirmed yet.
These should have no effect on CPU usage. You should normally leave these
settings to their defaults. Also, Forwarding and DirectOnly are not doing
anything in tinc 1.0.11.
> 1.0.11 is the latest package of Tinc I can find for Ubuntu 10.04; is
> it worth me trying to build or find a package for 1.0.16? I read the
> changes and it didn't appear that there were performance
> improvements for my case.
There are indeed no improvements for CPU usage, but there are a number of other
improvements and bug fixes in later versions, so it might be a good idea to
upgrade.
> Any other tips for performance tuning Tinc?
Most of the CPU time is consumed by encryption and authentication of all
packets. You can try changing the algorithms used with the Cipher and Digest
options. If you are sure you don't need encryption or authentication, you
can
set those to "none". But I would recommend not changing these settings
at all.

-- 
Met vriendelijke groet / with kind regards,
     Guus Sliepen <guus at tinc-vpn.org>
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