Re: strange performance problem

[Linos <info(at)linos(dot)es>]

> I have been testing with tcpdump but i dont see the problem in the 
> traffic (aside from the fact that it gives big jumps in ms between 
> packets of data, but i dont know why), i have tested on other debian 
> machines with the same result, i have upgraded kernel to 2.6.28 and 
> postgresql to 8.3.6 (equal versions of my Arch Linux Development 
> machine), but still have the same problem:
>
> -query with \timing with "psql -d database" ~110ms
> -query with \timing with "psql -d database -h localhost" ~4400ms
>
> Using tcp the cpu of postgresql spike to the max it can borrow within 
> the query. I have attached the tcpdump logs of a debian machine and the 
> Arch too (maybe anyone can see anything in them that i can not). How i 
> can test pure speed in the loopback interface? i have tried iperf but 
> seems to be cpu bound so maybe the results are misleading.

The pcap files are here for download, the mail with the attachment seems to not 
get into the list so here it is a link to download them.
http://www.linos.es/pcap_files.tar.bz2

Regards,
Miguel Angel.