Hi Marcus, On Tue, Dec 15, 2009 at 10:53:31AM +0100, Marcus Herou wrote: > Hi guys. > > I would appreciate it a lot if someone could share a sysctl.conf which is > known to run smoothly on a HAProxy machine with busy sites behind it.
This is a question I regularly hear. "very busy sites" does not mean much. Tuning is a tradeoff between being good at one job and being good at another one. People who run with very large numbers of concurrent connections will not tune the same way as people forwarding high data rates, which in turn will not tune the same way as people experiencing high session setup/teardown rates. People with large numbers of servers sometimes don't want to wait long on each request either while people with small numbers of servers will prefer to wait long in order not to sacrifice large parts of their clients in case something temporarily goes wrong. You see, that's just a tradeoff. You need to define a little bit your workload (bit rate, session rate, session concurrency, number of servers, response times, etc...). The more info you provide, the finer the tuning. > There > are so many variables that one possibly can fuck up so it is better to start > from something which is known to work. Well, I can tell you for sure that among the few people who are *really* experiencing high loads on busy machines, you won't find similar tuning, and that the few common parts will not help at all alone. And I would really recommend against blindly copy-pasting tuning parameters from another machine, as you can see your system collapse for no apparent reason (typical error is to copy tcp_mem settings with the wrong units). Regards, Willy
