December 2016 – UnixTeacher

Mass virtual hosting with apache through mod_rewrite

Published by tex on December 24, 2016

If you are a developer and you’re working with several subdomains for development purposes, you can create a single virtualhost, without the need to add subdomains and restart/reload the apache web server. Directory structure (example): /var/www /var/www/project1.unixteacher.org /var/www/project2.unixteacher.org /var/www/project3.unixteacher.org /var/www/development.unixteacher.org One single virtualhost for any subdomain: <VirtualHost *> DocumentRoot /var/www ServerName unixteacher.org ServerAlias *.unixteacher.org CustomLog…

HTTP DoS Protection with nginx

Published by tex on December 23, 2016

HTTP DoS Protection with Nginx through ngx_http_limit_conn_module and ngx_http_limit_req_module modules. The ngx_http_limit_conn_module module is used to limit the number of connections per the defined key, in particular, the number of connections from a single IP address. Not all connections are counted. A connection is counted only if it has a request processed by the server…

Hiding processes from other users on Linux

Published by tex on December 10, 2016

If you are running a recent Kernel, you can achieve this benefit by mounting the /proc filesystem with the new hidepid option. This option was added in Linux kernel 3.3 The proc filesystem is a pseudo-filesystem which provides an interface to kernel data structures. It is commonly mounted at /proc. Most of it is read-only,…

Tuning Nginx to handle more than 50.000 reqs/s

Published by tex on December 9, 2016

Hardware used in my test CPU: E3-1231 v3 CPU SPECS: 4 Core, 8 Threads – 3.40GHz Memory: 32 GB Storage: 4 x 240 GB SSD Force 3 Raid adapter: 3Ware 9750 Let’s beginning with os tuning. We will tweak sysctl.conf. # # file: ‘/etc/sysctl.conf’ # vm.swappiness = 0 vm.max_map_count = 262144 net.ipv4.tcp_wmem = 4096 65536…

Ethernet RTL 8168 driver on Debian

Published by tex on December 6, 2016

By default on Debian is used 8169 driver instead of 8168 (Realtek ethernet driver). Also, 8168 driver does not exist. ~# find /lib/modules/`uname -r`/kernel/drivers/net/ethernet/ -name *816* /lib/modules/3.16.0-4-amd64/kernel/drivers/net/ethernet/realtek/r8169.ko The network device ~# lspci |grep Ether 03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 09) The loaded driver ~# lsmod |grep…

Month: December 2016

Mass virtual hosting with apache through mod_rewrite

HTTP DoS Protection with nginx

Hiding processes from other users on Linux

Tuning Nginx to handle more than 50.000 reqs/s

Ethernet RTL 8168 driver on Debian