Log files are important for Linux system security and trouble shooting.  Log files tend to grow, and if a log grows too much you compress it and takes the backup. Logrotate enables you to do this in a much better way. The process that is in charge of compressing and rotating these logfiles is called logrotate and it is executed once per day upon Debian installations.

Here you will find the logrotate driver script. Every day this script runs and examines two things:

• The configuration file /etc/logrotate.conf
• The configuration directory /etc/logrotate.d/

A typical logrotate configuration file looks like this:

/var/log/apache/*.log {
        weekly
        missingok
        rotate 52
        compress
        delaycompress
        notifempty
        create 640 root adm
        sharedscripts
        postrotate
                if [ -f /var/run/apache.pid ]; then
                        /etc/init.d/apache restart > /dev/null
                fi
        endscript
}

If you want to add new log rotate for any other file you can new logrotate configuration file to /etc/logrotate.d 

Assuming we have a new service “mon” which produces its output in /var/log/mon/mon.log we can cause this to be rotated every day with a script like this:

/var/log/mon/*.log {
  daily
  missingok
  rotate 7
  compress
  delaycompress
  create 640 mon mon
  sharedscripts
     /etc/init.d/mon restart
  endscript
}

For more help man logrotate

HAProxy is a free, very fast and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It is particularly suited for web sites crawling under very high loads while needing persistence or Layer7 processing. Supporting tens of thousands of connections is clearly realistic with todays hardware. Its mode of operation makes its integration into existing architectures very easy and riskless, while still offering the possibility not to expose fragile web servers to the Net.

1. Preperation

For configuring haproxy you need the following setups. Here I used ACL.

1.1. Using ACL

The use of Access Control Lists (ACL) provides a flexible solution to perform content switching and generally to take decisions based on content extracted from the request, the response or any environmental status. The principle is simple

1.2. Load Balancer

Hostname: lb.example.com

IP: 192.168.0.110

1.3 Web Server 1

Hostname: http1.example.com

IP: 192.168.0.111

1.4. Web Server 2

Hostname: http2.example.com

IP: 192.168.0.112

1.5. First download and install haproxy

To get latest version click here

$ wget  http://haproxy.1wt.eu/download/1.2/src/haproxy-1.2.18.tar.gz
$ tar -xzvf haproxy-1.2.18.tar.gz
$ cd  haproxy-1.2.18
$ sudo make  TARGET=linux24

 1.6. Configuring Load Balancer System IP : 192.168.0.110

set ENABLED to 1 in /etc/default/haproxy

 $ sudo vim /etc/default/haproxy

# Set ENABLED to 1 if you want the init script to start haproxy.

ENABLED=1

# Add extra flags here.
#EXTRAOPTS="-de -m 16"

We back up the original /etc/haproxy.cfg and create a new one like this

cp /etc/haproxy.cfg /etc/haproxy.cfg_orig
cat /dev/null > /etc/haproxy.cfg
vi /etc/haproxy.cfg

Sample haproxy configuration file /etc/haproxy.cfg which uses ACL. In the below example if you use the domain example.com haproxy always uses web server 1,if you use loadbalancer.com

global
global
        log 127.0.0.1   local0
        log 127.0.0.1   local1 notice
        #log loghost    local0 info
        pidfile /var/run/haproxy.pid
        daemon
#       debug           # If you want to start haproxy in debugging mode uncomment this line and comment the above line.
        nbproc      4   # Number of processing cores. Dual Dual-core Opteron i    s 4 cores for example.
defaults
        log     global
        mode    http
        option  httplog
        option  httpchk
        option  dontlognull
        retries 3
        option          redispatch
        maxconn 2000
        contimeout      50000
        clitimeout      500000
        srvtimeout      500000

backend back_std
        balance roundrobin
        option redispatch
        cookie JSESSIONID prefix
        option httpclose
        option forwardfor
        option httpchk HEAD /check.txt HTTP/1.0
        server ws4 192.168.0.111:82 weight 1 check
#      stats uri /status   # Custom status URI
        stats auth username:password
        stats enable
        stats refresh 10

backend back_lb
        balance roundrobin
        option redispatch
        cookie JSESSIONID prefix nocache indirect
        option httpchk HEAD /check.txt HTTP/1.0
        server ws1 192.168.0.111:81 cookie ws1 weight 1 check
        server ws2 192.168.0.112:81 cookie ws2 weight 1 check
        option httpclose
        option forwardfor
        stats enable
        stats refresh 10

frontend http-in
        bind :80
        acl hosts_std hdr_end(host) -i example1..com          # Which is not load balanced
        acl hosts_std hdr_end(host) -i example1.com:80

        acl hosts_lb hdr_end(host) -i loadbalancer.com      # Which is load balanced
        acl hosts_lb hdr_end(host) -i loadbalancer.com:80

        use_backend back_std if hosts_std       # If requests comes to the domain which is in host_std then that URL will use back_std
        use_backend back_lb if hosts_lb          # If requests comes to the domain which is in host_lb then that URL will use back_lb

To allow HAProxy to bind to the shared IP address, we add the following line to /etc/sysctl.conf:

$ sudo vim /etc/sysctl.conf

[...]
net.ipv4.ip_nonlocal_bind=1
[...]

and run

$ sudo sysctl -p

1.7 Start haproxy

$ sudo /etc/init.d/haproxy start

1.8. Configuring Web Server 1 & Web Server2

We will configure HAProxy as a transparent proxy, i.e., it will pass on the original user’s IP address in a field called X-Forwarded-For to the backend web servers. Of course, the backend web servers should log the original user’s IP address in their access logs instead of the IP addresses of our load balancers. Therefore we must modify the LogFormat line in /etc/apache2/apache2.conf and replace %h with %{X-Forwarded-For}i:

 $ sudo vim /etc/apache2/apache2.conf

#LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
#LogFormat "%h %l %u %t \"%r\" %>s %b" common
#LogFormat "%{Referer}i -> %U" referer
#LogFormat "%{User-agent}i" agentLogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined

LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent

Also, we will configure HAProxy to check the backend servers health by continuously requesting the file check.txt (translates to /var/www/check.txt if /var/www is your document root) from the backend servers. Of course, these requests would totally bloat the access logs and mess up your page view statistics (if you use a tool like Webalizer or AWstats that generates statistics based on the access logs).

Therefore we open our virtualhost configuration (in this example it’s in /etc/apache2/sites-available/default) and put these two lines into it (comment out all other CustomLog directives in your vhost configuration):

$ sudo touch /var/www/check.txt
$ sudo vi /etc/apache2/sites-available/default

[...]
SetEnvIf Request_URI "^/check\.txt$" dontlog
CustomLog /var/log/apache2/access.log combined env=!dontlog
[...]

Adds the ports to /etc/apache2/ports.conf file.

Listen 81
Listen 82
<IfModule mod_ssl.c>
    Listen 443
</IfModule>

Afterwards we restart Apache:

$ sudo /etc/init.d/apache2 restart

Now to check the status of haproxy use the custom URI or use http://example1.com/haproxy?stats

I hope it helped, a comment with your questions are welcome 

php5
php5-cli
php5-dev
php5-sqlite
php-pear

$ sudo apt-get install php5 php5-cli php5-dev php5-sqlite php-pear

Test if Apache and PHP are up and running typing in the browser:

http://localhost/

You should see something like:

Apache/2.0.55 (Ubuntu) PHP/5.1.2-1ubuntu1 Server at localhost Port 80

From the command line, as root:

$ sudo pear upgrade PEAR
$ sudo pear channel-discover pear.symfony-project.com

Edit /etc/php5/cli/php.ini and change the line:

memory_limit = 8M To memory_limit = 16M

Then

$ sudo pear install symfony/symfony
$ sudo pear install –alldeps http://phing.info/pear/phing-current.tgz

Using the command:

$ sudo pear config-show

we find the symfony libraries have been installed in:

$ php_dir/symfony/ /usr/share/php/symfony/ main libraries
$ data_dir/symfony/ /usr/share/php/data/symfony/ skeleton of symfony applications, default modules and configuration
$ doc_dir/symfony/ /usr/share/php/docs/symfony/ documentation

From the command line enter bellow command:

$ symfony -Vsymfony version 0.6.2

From the command line, as root:

$ mkdir /var/www/myproject
$cd /var/www/myproject
$ symfony init-project myproject
$ symfony init-app myapp

Edit /Virtual Host configuration file , and append the following at the end:

<VirtualHost 192.168.1.2:81>
ServerAdmin webmaster@localhost
ServerName servername.com
ServerAlias www.servername.com
DocumentRoot /var/www/project/web
Alias /sf /usr/share/php/data/symfony/web/sf
<Directory /var/www/project/web>
     Options FollowSymLinks MultiViews
     AllowOverride all
     Order allow,deny
     allow from all
</Directory>
</VirtualHost>

If you request a non existent page on a server .It will not show up your normal Apache custom 404 page.

A trick to show a custom page ( eg: cferror.cfm ) when a non existant cfm page is accessed. This can be done with the .htaccess file. .htaccess is a regular text file that contains “scripts” that allow you to override certain things on your server – like creating a custom 404 error document that replaces the server’s default 404 document.

Method 1

To be able to create your own 404 error document, first you need to create the actual document (use your HTML editor of choice or hand code it if you like), upload the document to the root directory on your server, and finally include the following in your document root .htaccess file:

ErrorDocument 404 http://www.yourdomain.com/404.html

 Method 2

Add the following entry to the .htaccess file in your DocumentRoot

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule (.*) /cferror.cfm?%{REQUEST_URI}

All request to the non existent pages are passed to cferror.cfm page with the requested URL as argument.