Master Nginx: From Installation to Load Balancing and Service Scripts

1. Test Nginx Configuration

nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

2. Start Nginx

/usr/local/nginx/sbin/nginx

3. Nginx Load Balancing

Nginx architecture and load‑balancing concepts are illustrated below.

Load‑balancing diagram:

Nginx upstream currently supports five distribution methods:

Round Robin (default) : requests are assigned sequentially; failed back‑ends are automatically removed.

Weight : assign a weight to each server; higher weight receives proportionally more traffic.

ip_hash : hash the client IP so a client consistently reaches the same back‑end, useful for session persistence.

fair (third‑party) : prefers servers with shorter response times.

url_hash (third‑party) : hashes the request URL, directing the same URL to the same back‑end, beneficial for caching.

4. Install and Configure Nginx

(1) Build from source

# Change to source directory
cd /usr/local/src/
# Download source tarball
wget http://syslab.comsenz.com/downloads/linux/nginx-0.9.6.tar.gz
# Extract and enter directory
tar zxvf nginx-0.9.6.tar.gz
cd nginx-0.9.6
# Configure with desired options
./configure \
  --prefix=/usr/local/nginx \
  --sbin-path=/usr/local/nginx/sbin/nginx \
  --conf-path=/usr/local/nginx/conf/nginx.conf \
  --error-log-path=/usr/local/nginx/logs/error.log \
  --http-log-path=/usr/local/nginx/logs/access.log \
  --pid-path=/usr/local/nginx/var/nginx.pid \
  --lock-path=/usr/local/nginx/var/nginx.lock \
  --http-client-body-temp-path=/dev/shm/nginx_temp/client_body \
  --http-proxy-temp-path=/dev/shm/nginx_temp/proxy \
  --http-fastcgi-temp-path=/dev/shm/nginx_temp/fastcgi \
  --user=www --group=www \
  --with-cpu-opt=pentium4F \
  --without-select_module \
  --without-poll_module \
  --with-http_realip_module \
  --with-http_sub_module \
  --with-http_gzip_static_module \
  --with-http_stub_status_module \
  --without-http_ssi_module \
  --without-http_userid_module \
  --without-http_geo_module \
  --without-http_memcached_module \
  --without-http_map_module \
  --without-mail_pop3_module \
  --without-mail_imap_module \
  --without-mail_smtp_module \
  --with-pcre=/usr/local/src/pcre-8.32/ \
  --with-zlib=/usr/local/zlib
# Build and install
make && make install
# Create temporary directory for fastcgi buffers
mkdir /dev/shm/nginx_temp

Some Nginx versions may fail to compile PCRE; ensure the PCRE source is extracted to /usr/local/src/pcre-8.32 and use --with-pcre=/usr/local/src/pcre-8.32 without rebuilding PCRE.

(2) Install required dependencies

# Install build tools
apt-get --install-suggests install gcc g++ make
# Download additional libraries
wget http://jaist.dl.sourceforge.net/project/pcre/pcre/8.35/pcre-8.35.tar.gz
wget http://zlib.net/zlib-1.2.8.tar.gz
wget http://www.openssl.org/source/openssl-1.0.1g.tar.gz
wget http://www.canonware.com/download/jemalloc/jemalloc-3.6.0.tar.bz2
wget http://tengine.taobao.org/download/tengine-2.0.2.tar.gz
# Build and install PCRE
tar zxvf pcre-8.35.tar.gz
cd pcre-8.35
./configure --prefix=/usr/local/pcre-8.35
make && make install
# Build and install Zlib
cd ..
tar zxvf zlib-1.2.8.tar.gz
cd zlib-1.2.8
./configure --prefix=/usr/local/zlib-1.2.8
make && make install

If you encounter the error "the HTTP gzip module requires the zlib library", either disable the module with --without-http_gzip_module or provide the Zlib library via --with-zlib=<path>. Another common error is missing a C++ compiler for PCRE; install a suitable C++ compiler.

After successful installation, the configuration summary looks like:

[Nginx Configuration Summary]
+ using PCRE library: /usr/local/src/pcre-8.32
+ OpenSSL library is not used
+ using builtin md5 code
+ sha1 library is not found
+ using zlib library: /usr/local/zlib
nginx path prefix: "/usr/local/nginx"
nginx binary file: "/usr/local/nginx/sbin/nginx"
nginx configuration prefix: "/usr/local/nginx/conf"
nginx configuration file: "/usr/local/nginx/conf/nginx.conf"
nginx pid file: "/usr/local/nginx/var/nginx.pid"
nginx error log file: "/usr/local/nginx/logs/error.log"
nginx http access log file: "/usr/local/nginx/logs/access.log"
nginx http client request body temporary files: "/dev/shm/nginx_temp/client_body"
nginx http proxy temporary files: "/dev/shm/nginx_temp/proxy"
nginx http fastcgi temporary files: "/dev/shm/nginx_temp/fastcgi"
nginx http uwsgi temporary files: "uwsgi_temp"
nginx http scgi temporary files: "scgi_temp"

(2) Create an init script for Nginx

#!/bin/bash
# Startup script for the Nginx HTTP Server
NGINX_PATH="/usr/local/nginx/"
OPTIONS="-c ${NGINX_PATH}conf/nginx.conf"
prog=nginx
nginx=${NGINX_PATH}sbin/nginx
pidfile=/var/run/nginx.pid
. /etc/rc.d/init.d/functions

start() {
  echo -n "Starting $prog: "
  daemon --pidfile=${pidfile} $nginx $OPTIONS
  RETVAL=$?
  echo
  return $RETVAL
}

stop() {
  echo -n "Stopping $prog: "
  killproc -p ${pidfile} $nginx
  RETVAL=$?
  echo
}

reload() {
  echo -n "Reloading $prog: "
  killproc -p ${pidfile} $nginx -HUP
  RETVAL=$?
  echo
}

case "$1" in
  start)   start   ;;
  stop)    stop    ;;
  restart) stop; start ;;
  reload)  reload  ;;
  status)  status $prog; RETVAL=$? ;;
  *) echo "Usage: $prog {start|stop|restart|reload|status}"; RETVAL=3 ;;
esac
exit $RETVAL

Make the script executable and enable it at boot:

chmod 755 /etc/init.d/nginx
chkconfig --add nginx
chkconfig nginx on