2.2.x Network troubles

Peter Zaitsev (pz@spylog.ru)
Thu, 20 Jul 2000 10:45:06 +0400

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I'm running 2.2.x kernel in specific network load (web counter serving =
15millions of buttons per day). Currently I increased=20
/proc/sys/net/ipv4/tcp_max_syn_backlog to 2048=20
/proc/sys/ner/ipv4/route/max_size to 16384

The number of connections open is:

[root@mars dem]# netstat -nt | wc -l
15395
[root@mars dem]# netstat -nt | grep SYN | wc -l
358

So it does not seems to hit the limit of max_syn backlog.

The problem is - it seems in 1-3% of the requests connect takes several =
seconds which, which is the problem in my case.
Looking at VMSTAT shows 40-60% of CPU is idle anytime.

Any ideas how to solve such problem ?
I have tried several stable kernels from 2.2.14 to 2.2.16 with =
different patch sets (RedHat,aa-series) all seems to have the same =
problem....

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I'm running 2.2.x kernel in specific = network load=20 (web counter serving 15millions of buttons per day).  Currently I = increased=20
/proc/sys/net/ipv4/tcp_max_syn_backlog to=20 2048
/proc/sys/ner/ipv4/route/max_size = to =20 16384
 
The number of connections open=20 is:
 
[root@mars dem]#  netstat = -nt | wc=20 -l
  15395
[root@mars dem]#  netstat = -nt | grep SYN=20 | wc -l
    358
 
So it does not seems to hit the = limit of=20 max_syn backlog.
 
The problem is - it seems in 1-3% = of the=20 requests connect takes several seconds which, which is the problem in my = case.
Looking at VMSTAT shows 40-60% of = CPU is idle=20 anytime.
 
Any ideas how to solve such = problem=20 ?
I have tried several stable = kernels from=20 2.2.14 to 2.2.16  with different patch sets (RedHat,aa-series) all = seems to=20 have the same problem....
 
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