Re: Problem wit route cache

[Eric Dumazet <eric.dumazet@gmail.com>]

Le lundi 08 février 2010 à 14:33 +0100, Paweł Staszewski a écrit :

> >    
> Yes this is x86_64 kernel
> i kernels  2.6.32.2 /  2.6.32.7 and now 2.6.33-rc6-git5 and on all 
> kernels the same thing happens.
> grep . /proc/sys/net/ipv4/route/*
> /proc/sys/net/ipv4/route/error_burst:1250
> /proc/sys/net/ipv4/route/error_cost:250
> grep: /proc/sys/net/ipv4/route/flush: Permission denied
> /proc/sys/net/ipv4/route/gc_elasticity:2
> /proc/sys/net/ipv4/route/gc_interval:2
> /proc/sys/net/ipv4/route/gc_min_interval:0
> /proc/sys/net/ipv4/route/gc_min_interval_ms:500
> /proc/sys/net/ipv4/route/gc_thresh:65535
> /proc/sys/net/ipv4/route/gc_timeout:300
> /proc/sys/net/ipv4/route/max_size:524288
> /proc/sys/net/ipv4/route/min_adv_mss:256
> /proc/sys/net/ipv4/route/min_pmtu:552
> /proc/sys/net/ipv4/route/mtu_expires:600
> /proc/sys/net/ipv4/route/redirect_load:5
> /proc/sys/net/ipv4/route/redirect_number:9
> /proc/sys/net/ipv4/route/redirect_silence:5120
> /proc/sys/net/ipv4/route/secret_interval:2
> 
> This happens not all the time.
> I have this info only when there are "internet rush hours" - thn there 
> is about 700Mbit/s TX + 700Mbit/s RX forwarded traffic
> 

I dont understand your settings, they are very very small for your
setup. You want to flush cache every 2 seconds...

With 12GB of ram, you could have 

/proc/sys/net/ipv4/route/gc_thresh:524288
/proc/sys/net/ipv4/route/max_size:8388608
/proc/sys/net/ipv4/route/secret_interval:3600
/proc/sys/net/ipv4/route/gc_elasticity:4
/proc/sys/net/ipv4/route/gc_interval:1

That would allow about 2 million entries in your route cache, using 768
Mbytes of ram, and a good cache hit ratio.