Re: [Openvpn-users] latency issues on larger scale OpenVPN setup

[Samuli S. <sa...@op...>]

> The challenge with OpenVPN is that redesigning a single-threaded
> application to become a multi-threaded one is not as easy as it often
> sounds like.  And you would actually be able to manage pretty much the
> same result as if you would just do it in a single thread.  If OpenVPN
> would just defer the waiting while re-keying, taking care of some other
> connections in the mean time, this would solve this lag.  And without
> having looked too much at the previous attempt, I believe this was what
> it was trying to do.  But this approach makes it tricky, as the re-keying
> might be prune to fail if the further RSA process is postponed for too
> long.  And this could happen in a large site, with many active VPN
> clients pushing data.
>
Let me play the devil's advocate here.. what if the current approach -
single-threaded but multiple processes - makes more sense than going
multi-threaded? Threads are lighter than processes, but also make the
code more complex (and error-prone). Do we get any other benefits from
threads besides better utilisation of multiple processor cores?

-- 
Samuli Seppänen
Community Manager
OpenVPN Technologies, Inc

irc freenode net: mattock