- Load balancing the Webserver (http/https traffic) using Pound on Linux

The Pound program is a reverse proxy, load balancer and HTTPS front-end for Web server. Pound was developed to enable distributing the load among several Web-servers and to allow for a convenient SSL wrapper for those Web servers that do not offer it natively.

WHAT POUND IS:
  * A reverse-proxy: it passes requests from client browsers to one or more back-end servers.
  * A load balancer: it will distribute the requests from the client browsers among several back-end servers, while keeping session information.
  * An SSL wrapper: Pound will decrypt HTTPS requests from client browsers and pass them as plain HTTP to the back-end servers.
  * An HTTP/HTTPS sanitizer: Pound will verify requests for correctness and accept only well-formed ones.
  * A fail over-server: should a back-end server fail, Pound will take note of the fact and stop passing requests to it until it recovers.
  * A request redirector: requests may be distributed among servers according to the requested URL.

Pound is a very small program, easily audited for security problems. It can run as setuid/setgid and/or in a chroot jail. Pound does not access the hard-disk at all (except for reading the certificate file on start, if required) and should thus pose no security threat to any machine.

Installation:
OpenSuSe user can install pound using "1-click" installer - here

Others - Download and unpack the source tarball, installation is the standard ./configure&&make&&make install. (If you plan on utilizing Pound's SSL support, specify ./configure ––with-ssl.

Look for the pound executable in /usr/local/sbin and look for the configuration file, pound.cfg, in /usr/local/etc.

Next, configure Pound. Here's a simple pound.cfg file:

ListenHTTP
Address 1.2.3.4
Port 80
Service
  Backend
    Address 192.168.0.1
    Port 80
  End
  Backend
    Address 192.168.0.2
    Port 80
  End
End

This instructs Pound to listen on the public IP address 1.2.3.4 and pass requests evenly to the two backend machines named with Service. If the machines have significantly different resources available to them, you can alter the odds of a server being chosen with the Priority directive. Values may be 1 through 9, where the value 9 means use most often, and the value 1 means least frequent. Pound balances servers dynamically: if a server goes down, Pound automatically removes the system from the pool of available servers.

Many web applications use sessions and Pound can track sessions between a client browser and the host backend server. Pound supports five techniques: client IP address, basic authentication, URL parameter, cookie value, and header value. Only one session definition is allowed per Service.

For example, to use client IP-based tracking that keeps sessions active for ten minutes, add the following to your Pound config file:

Session
  Type IP
  TTL 600
End

To harden Pound, run the daemon as a non-privileged user. To do this, use the User and Group directives to specify the user and group, respectively:

User    "nobody"
Group   "nobody"

Keep in mind that after adding Pound into your network setup, your backend servers will log the IP address of your Pound machine instead of the client IP of the person browsing your site. As a general rule, Pound passes all headers as set by the client to the backend servers, with two exceptions: Pound adds a X-Forwarded-For header, and may add information about the SSL certificate.

You can use the X-Forwarded-for header to update your logging mechanism to record the correct information.

For example, If you're using Apache combined logging, replace the letter h (remote host) with:

\"%{X-Forwarded-for}i\"

source:http://linuxpoison.blogspot.com/2010/04/135781677513160.html

- Powerful, Fast and Reliable Backup & Sync tool - luckyBackup

LuckyBackup is a powerful, fast, reliable, and fully customizable backup and sync tool. It can backup any directory (the source) to another (the destination).

luckyBackup copies over only the changes you've made to the source directory and nothing more, saving a great deal of time for backups after the first one. Whatever changes you make to the source, including adding, moving, deleting, modifying files or directories, will have the same effect on the destination. Owner, group, time stamps, links, and permissions of files are preserved (unless directed otherwise). The synchronization feature works on any pair of directories, keeping the files that were most recently modified on both of them. It includes many safety checks to prevent accidental loss of data.

Features of LuckyBackUp
  * Easy and safe creation of a remotely located clone of your existing data. After the first backup of the source directory, LuckyBackUp will copy only the changes made. Links, permissions, time stamps, owner, and groups are preserved unless stated otherwise.
  * You can sync files between directories, it’s a handy tool if you work on more than one machine. You do not have to keep track of the last directory you modified.
  * The tool ensures data safety by first checking if the database that you have declared actually exists.
  * There are a lot of options for users tabbed as Simple and Advanced.
  * An exclude button lets you exclude any file or folder from the transfer process.
  * An only include option will let you backup only specific files, folders, and patterns within your source directory.
  * You can alter the default rsync options that LuckyBackUp provides.
  * Use remote connections either as source or destination folder.
  * Commands can be executed before or after a specific task.
  * A very handy “restore” function to undo unintentional deletes or mistakes.
  * Simulate an rsync in a dry run before actuating the actual job.
  * You can create and save multiple profiles so that you don’t have initiate a task from scratch every time you wish to perform it.
  * You can schedule tasks under already created profiles via cronjobs.
  * A logfile in your home folder records all tasks.
  * You can run the application either via the GUI or the command line.

Installation:
OpenSuSe / Fedora / CentOS user can download the LuckyBackup rpm file and can install LuckBackup using following command:

rpm -ivh luckybackup-0.3.5-1.i686.rpm

Once installed open up a terminal window and issue the command luckybackup. This command will open up the user-friendly gui where you add all of the backups you want to create.

Using LuckyBackup:

Step 1: Click the Add button
  Name: Name to give the backup.
  Type: Full or incremental.
  Source: What you want to backup.
  Destion: Directory on local or remote host to store backup.

Step 2: Click Okay to save your settings.

Step 3: Click Start to begin the backup process.

If your backup was setup correct you will immediately be informed such and, in the terminal window you can see the progress of your backup.

source:http://linuxpoison.blogspot.com/2010/04/13578167758893.html