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Software:
debian woody, stock 2.4.24 kernel + frees/wan.
Hardware:
AMD XP2400+
VT8377 [KT400] MB
eth0=via rhine II (VT6102, on board)
eth1=3c950C
1Gb memory
LVS Configuration:
LVS-NAT + firewall mark setup. Ports 1755/tcp, 554/tcp, 554/udp,
1024:5000/udp are grouped together. I realise LVS-NAT is not ideal here but
the director is also the gateway, so it seemed like the simplest way to
proceed initially. I then have:
ipvsadm -D -f 1
ipvsadm -A -f 1 -s rr -p 600
ipvsadm -a -f 1 -r 10.90.90.7:0
i.e. single media server and using persistence to keep the grouping. This
all works fine (i.e. I can stream media).
I then load test this using a setup like:
eth1
test box --- director --- media server
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------------- eth0
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outside world via some cisco router or other
so the test box and the director are on the same LAN (connected via some
cisco switch), and the media server and the director are on a different LAN
(connected via a cheap D-Link switch).
The test box is using the Windows Media Load Simulator. This just makes a
lot of connections and streams back data. The average stream only gets up
to about 35Mbit. At this point, CPU usage on the director is ~20% (which
would seem to indicate that I should be able to get a lot more out of it).
CPU on the test box is at about 25% and on the media server at 4%.
The problematic part is that the director begins dropping about 10% of
externally originated packets at this level of load. I wouldn't say any
machine involved is stressed here, but pinging the external IP of the
director gives that huge loss. This noticeably affects say, SSH, on the
director or TS to the media server. This is constrasted with pinging the
external IP of the test box, which gives 0% loss.
I would therefore conclude that this is an issue with the director, but I'm
not sure what. My next guess would be to try swapping the VIA NIC for
another 3com one, but could it really be that bad? I can't see it being an
issue with the cisco switch (test box and director are both connected to
it); the cisco router (same), or the d-link switch (not involved in ping to
director), so I'm at a loss as to what else to conclude.
Thanks,
Mark
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