Hello, Working with 1000 containers I had already modified gc_thresh* to fit my needs.
By mistake I had set gc_interval to a too high value (past 2^32) , forcing linux to set gc_interval to the default value (30) with is not suitable in my case. Setting gc_interval to 3600000 solved my problem. Thanks for pointing me in the right direction Benoit On 24/04/2013 07:21, "Guido Jäkel" <g.jae...@dnb.de> wrote: >Dear Benoit, > >there's a lot of local matching and translation between layer2 and layer3 >in your case. I wounder if it is related to the apr cache size and >garbage parameters. I found [http://linux.die.net/man/7/arp]: > > gc_interval (since Linux 2.2) > How frequently the garbage collector for neighbor entries should >attempt to run. Defaults to 30 seconds. > gc_stale_time (since Linux 2.2) > Determines how often to check for stale neighbor entries. When a >neighbor entry is considered stale, it is resolved again before sending >data to it. Defaults to 60 seconds. > gc_thresh1 (since Linux 2.2) > The minimum number of entries to keep in the ARP cache. The garbage >collector will not run if there are fewer than this number of entries in >the cache. Defaults to 128. > gc_thresh2 (since Linux 2.2) > The soft maximum number of entries to keep in the ARP cache. The >garbage collector will allow the number of entries to exceed this for 5 >seconds before collection will be performed. Defaults to 512. > gc_thresh3 (since Linux 2.2) > The hard maximum number of entries to keep in the ARP cache. The >garbage collector will always run if there are more than this number of >entries in the cache. Defaults to 1024. > >This still seems to be the default on recent kernels, on a box with 3.3.5 >I found > > root@bladerunner9 ~ # cat /proc/sys/net/ipv4/neigh/default/gc* > 30 > 60 > 128 > 512 > 1024 > >If the ARP cache get's exhausted, there must be continous additional ARP >resolution traffic and latency. May you check this theory? > > >Greetings > >Guido > > >On 2013-04-23 23:34, Benoit Lourdelet wrote: >> Hello, >> >> Forwarding throughput is decreasing gradually as I add containers. I >>don't >> see any sudden drop. >> >> I we consider aggregated forwarding performance with 100 containers to >>be >> 1, here are the measurements for >> >> # containers Aggregated throughput >> ------------------------------------ >> 100 1 >> 500 .71 >> 1000 .27 >> 1100 .23 > ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr _______________________________________________ Lxc-users mailing list Lxc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lxc-users
