Apache

Running a redundant apache server does not require much from apache itself, but rather the underlying filesystem and a proxy in front of it. The filesystem is important, so the website and its php sessions can be shared between the servers. For this we will use GlusterFS. The proxy in front of apache will be a combination of HA-proxy and Corosync.

In this setup we will configure 2 apache servers. None of these will be master/slave/primary/secondary. They will just be running with the same configuration. Since the servers are configure the same way it makes sense to share some files.

192.168.1.50 www01
192.168.1.51 www02

Software

apt-get install apache2 php php-mysql

Filesystem

Configure your system as a GlusterFS client, so you have the following in your fstab.

/etc/glusterfs/www.vol /var/www glusterfs defaults,_netdev,rw 0 0

Testpage

Make a simple webpage, that shows something unique about the system. This is usefull when debugging. index.php

   1 <?php
   2         echo "client: " . $_SERVER['REMOTE_ADDR'] . "\n";
   3         echo "server: " . $_SERVER['SERVER_ADDR'] . "\n";
   4         echo "hostname: " . gethostname() . "\n";
   5 ?>

-  ⇤ ← Revision 13 as of 2018-01-04 13:44:42 → 
  Size: 835
  Editor: Kristian Kallenberg
  Comment:
+   ← Revision 23 as of 2018-01-20 22:11:07 → ⇥
  Size: 1335
  Editor: Kristian Kallenberg
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
+incomplete, do not use!
-Line 5:
+Line 6:
-In this setup we will configure 2 apache servers.
+In this setup we will configure 2 apache servers. None of these will be master/slave/primary/secondary. They will just be running with the same configuration. Since the servers are configure the same way it makes sense to share some files.

 * 192.168.1.50 www01
 * 192.168.1.51 www02
-Line 15:
+Line 19:
-Configure your system as a Gluster Client, so you have /var/www on a GlusterFS.
Make a simple webpage, that shows something uniq about the system. This way we can later on see which server HA-proxy redirects to,
+Configure your system as a [[GlusterFS Client|GlusterFS client]], so you have the following in your fstab.
{{{
/etc/glusterfs/www.vol /var/www glusterfs defaults,_netdev,rw 0 0
}}}
-Line 18:
+Line 24:
+== Testpage ==
Make a simple webpage, that shows something unique about the system. This is usefull when debugging.
-Line 21:
+Line 29:
-echo gethostname();
+        echo "client: " . $_SERVER['REMOTE_ADDR'] . "\n";
        echo "server: " . $_SERVER['SERVER_ADDR'] . "\n";
        echo "hostname: " . gethostname() . "\n";