[j-nsp] transfer between 2 ns2000's is slow

[Stefan Fouant]

On Tue, Feb 10, 2009 at 2:46 PM, Leslie <leslie at craigslist.org> wrote:
>
> I can blast udp across this pipe without a problem, but tcp traffic seems to
> be limited to about 3 mbyte/s -- I can make multiple sessions that are all
> transferring at this speed, but no individual session will go over that
> "limit"

Do you have any content filtering going on, such as Anti-Virus
Scanning?  Often these have an associated trickle size and other
parameters which limit file transfers.  What about traffic shaping?

> Another thing that makes me extremely suspicious is occasionally when I
> start a transfer I'll see a brief cpu spike -- like shown below

It's not so unusual to see a brief CPU spike when the sessions are
starting up - the first packet has to be processed via First Packet
processing, typically being punted up to the CPU for analysis for
determination as to whether the packet should be allowed by policy.
If it is allowed, it is instantiated in the session table and
subsequent packets are processed via Fast Packet processing, which
essentially means it's handled via the GigaScreen ASICs and not via
the main CPU.

-- 
Stefan