haproxytechblog

#
# This is the ultimate HAProxy 2.0 "Getting Started" config
# It demonstrates many of the features available which are now available 
# While you may not need all of these things, this can serve
# as a reference for your own configurations.
#
# Have questions?  Check out our community Slack:
# https://slack.haproxy.org/
#

bradfa

"Hardware" Notes

• Need OVMF UEFI firmware for 64 bit machines installed. Be sure guest is using UEFI firmware! You can't change this after you create a machine in virt-manager!
• Be sure using i440FX chipset.
• Enable a qemu-ga channel for guest. Make a VirtIO serial controller.
• Make sure your hard disk is using VirtIO, not IDE.
• Be sure you have the VirtIO floppy image for Windows 7 install, you'll need to load drivers so installer can see the VirtIO disk.
• Bridging to main Ethernet interface works fine, depsite the warnings. Use the VirtIO ethernet type.
• The VirtIO 0.1.141 drivers work well for me in Win 7 Pro 64 bit.
• To avoid the NVIDIA "Code 43" error, see the Arch Linux wiki about modifying the hypervisor name. Or somehow find older NVIDIA drivers prior to version 337 that work with your card.
• Remove the "sound" device, sound pass through sucks. Just pass through a USB sound card/device but this isn't needed at install time.

denji

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD