Linux 2.3.x + Network + Speed...

[Terry Katz]

Hello...

I was wondering if there are there any issues with v2.3.x and networking?

We are trying to run a high volume web server that acts solely as a proxy...
We had tested Linux's performance a few months back on a single cpu P2-400
with 512mb ram (and kernel 2.2.12 or so)... The system ran fine at approx ~1
million hits an hour (it was set up exactly like our current server).

We placed our test setup into production as a Quad P3 Xeon-550/2mb with 1gig
ram, running Linux 2.3.34 and the NAT netfilter module (0.1.14), for
forwarding real audio ports to the real server.  The server is barely
getting by on less than 500,000 hits an hour, with a load average at about
20-30, and 90%+ system load (little user load, and little idle).  When the
system gets like this, our average transfer rate to the backend webserver,
connected on the same switch, at 100mbps is about 80-160k/s (as opposed to
3000k/s or more when idle).  The kernel log shows a lot of 'TCPv4 bad
checksum' messages (couple per minute), and the ip_conntrack module is
logging 'ip_conntrack: Wow someone raced us!' often...  (our 2.2.x linux
boxes don't have any bad checksum messages..)... We're planning to fall back
to 2.2(+ipchains) to see if the performance is better...

The box configuration is:
  Dell PowerEdge 6300
  4xXeon 550/2mb
  1gig ram
  AMI MegaRaid dual channel controller
  2 Intel EtherExpress Pro load balancing cards (not using loadbalancing)
  Linux 2.3.34 + netfilter 0.1.14 (stock kernel, custom compiled)
    Optimized as a router (maybe this is a problem??)
    Masquerading enabled
    NAT port forwarding enabled on real audio and mysql ports
    (I can supply the full config if needed)
  /proc/net/ip_conntrack shows 10,000+ connections at any one time (active,
and timewait, etc..)

Any ideas?

Thanks,
  Terry