Messages in this thread | | | Subject | Re: Linux 2.4.22-pre10 | From | Martin Josefsson <> | Date | 02 Aug 2003 20:28:46 +0200 |
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On Sat, 2003-08-02 at 20:10, Willy Tarreau wrote:
> > Have you tried using the ULOG target and the ulogd userspace daemon? > > It uses netlink and can batch several entries together before it sends > > them to userspace. Works a lot better than syslog. > > yes, I tried it about february. I thought it to be the ideal solution, and it > performed better than the standard syslog, but not as well as syslog-ng. I > could catch about 1500 lines/s at most, and the daemon was very hungry, it ate > between 55 and 70% of the CPU, while syslog-ng eats about 25-30. So I thought > it was still a bit experimental and switched to syslog-ng.
Uhm, my tests have shown it to be very fast and efficient. But I didn't look to see if all packets got through to the logfile. But getting it to write logs at ~35MB/s wasn't a problem.
Did you specify --ulog-qthreshold 50 ? and did you specify --ulog-cprange at all? if you don't it will copy the entire packet to userspace. I copy 64 bytes to userspace and that's more than enough to log everything needed.
> > Are you using ip_conntrack on that machine? if you are, be aware that > > ip_conntrack doesn't scale well at all on SMP. It's beeing worked on. > > Yes I do. I noticed the scalability problems a long time ago on my dual athlon > at home, but wasn't really concerned. At my customer's, the only SMP one is > used as a development gateway. All the others are UP (PIII/1G, P4/2.4G).
Ok, we are working on memory-usage and scalability stuff.
> BTW, I get the same numbers with 2.4.22-pre10 / standard ip_conntrack as with > 2.4.21-rc2 with tcp_window_tracking. I would have thought that > tcp_window_tracking costs a bit more, but it doesn't seem to be noticeable here.
It should cost a little bit more but not very much.
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