Linux Kernel Tuning for C500k • Hacker News Board

Re: Linux Kernel Tuning for C500k

#21

Post by c00p3r » Thu, Sep 30, 2010, 1:26 AM UTC

superjared wrote: post #7

chrisbolt wrote: post #2

My, how things have changed since the C10k problem... http://www.kegel.com/c10k.html

The C10k solutions are effectively the same as for C500k, those being epoll (Linux), kqueue (BSD), etc. Our Java NIO server utilizes epoll to handle C500k.

What Java NIO server utilizes for EINTR? ^_^

Re: Linux Kernel Tuning for C500k

#22

Post by c00p3r » Thu, Sep 30, 2010, 1:35 AM UTC

btw, the most common source of high load is (surprise!) disk I/O.

So, moving a /var/log (not just /var) on separate device connected to distinct controller port is a big deal.

If you're running, say, mail server, you should separate /var/spool and /var/log and /var/db/mysql if any.

Partitioning, serious network card (think Broadcom) and big CPU caches are good things to begin with.

Re: Linux Kernel Tuning for C500k

#23

Post by nwmcsween » Thu, Sep 30, 2010, 1:37 AM UTC

This isn't relevant to newer kernels as these settings are dynamic based on memory size since 2.6.26ish - The kernel will set this based on usage no need to tweak. The only real issue is making sure you buy a high end network card that will offload as much as possible to avoid x context switches per second (I don't know what it is exactly with netpoll).

Re: Linux Kernel Tuning for C500k

#24

Post by JoachimSchipper » Thu, Sep 30, 2010, 9:11 AM UTC

Linking this with the IPv6 stuff currently on the front page: note that none of this would be necessary if the clients were running IPv6 (or otherwise un-NAT-ed) - the server could simply send them a UDP packet or even open a TCP connection.

Re: Linux Kernel Tuning for C500k

#25

Post by ciupicri » Thu, Sep 30, 2010, 6:20 PM UTC

c00p3r wrote: post #22

btw, the most common source of high load is (surprise!) disk I/O. So, moving a /var/log (not just /var) on separate device connected to distinct controller port is a big deal. If you're running, say, mail server, you should separate /var/spool and /var/log and /var/db/mysql if any. Partitioning, serious network card (think Broadcom) and big CPU caches are good things to begin with.

Broadcom on Linux?! I was under the impression that their drivers aren't too good or open source friendly.

Re: Linux Kernel Tuning for C500k

#26

Post by nivertech » Tue, Oct 05, 2010, 4:22 PM UTC

Did somebody solved C1000K (or C1M) problem?

http://news.ycombinator.com/item?id=1755575

Is maximum number of connections that you can reach on largest EC2 instance is the same as on physical server?