WOW. Make sure you have - in front of the filename? >
This makes quite a difference! Before: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sdb 0.00 303.60 0.00 736.46 0.00 4160.24 11.30 0.73 1.00 0.98 72.53 After: Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sdb 0.00 12.29 0.00 3.00 0.00 122.28 40.80 0.01 4.33 3.00 0.90 CPU has doubled, however. To 2%. Thanks John! James 2009/2/11 John Lauro <[email protected]> > It shouldn't be too hard for a machine to keep up with logging. How are > you logging? standard syslog? Make sure you have - in front of the > filename? How connections per second are you logging? > > > > Haven't done it with Haproxy, but have with other things that generate tons > of logs… > > > > what you could do is dump the logs (don't forget the – as part of the file > name) to /dev/shm/ (assuming linux), and then rotate the logs once a minute > and process them… That way, you will not have any disk I/O from the logs, > but would increase memory requirements. > > > > > > > > *From:* James Brady [mailto:[email protected]] > *Sent:* Wednesday, February 11, 2009 12:14 PM > *To:* [email protected] > *Subject:* Reducing I/O load of logging > > > > The machine we run HAProxy on is approaching its limits in terms of disk > I/O due to our debug-level logging. > > > > The CPU is barely used, memory is no problem at all - the bottleneck will > soon be the rate at which we can log to disk. Because the machine is more > than adequate in all other areas, we'd really like to reduce the I/O load of > logging. > > > > We are using the debug log output to tell us the response time and status > code for various URLs - this is an essential task we can't do without. > > > > Is there any way to get this information without logging and > post-processing every request? Can HAProxy dump out averaged statistics like > this? Can we somehow reduce the I/O load by just logging the exact fields > we're interested in? > > > > Many thanks! > > James >
