Linux Nuggetz

How to enable clustering in Openfire Enterprise?

2010-08-26T16:51:00.004+08:00

What is clustering?

A cluster is when you have several servers hosting the same domain. Before Openfire 3.4.0 it was possible to only have one machine hosting a domain. Even though a single machine can scale to very big numbers (e.g. more than 100K concurrent users) there is still a limit in the number of users you can scale. Moreover, if that machine suffers a problem and the server stops then all users will be affected.

When using clustering you avoid those two problems. You will be naturally distributing the load among several machines thus even if one of them goes down the entire service will still continue to respond. The users that were connected to the machine that went down will just reconnect to any of the remaining machines.

How do I use clustering in Openfire?

Clustering is a commercial feature that is available in the Openfire Enterprise 3.4.0 or later. That means that you need to get Openfire Enterprise to be able to use clustering. If you have an existing Openfire Enterprise license you will need to update it since the max number of members that could be part of the cluster is kept in the license. If you don't have an enterprise license and would like to try the clustering feature you can get an evaluation license for 30 days.

Follow these steps to install Openfire Enterprise with clustering:

1. Identify the machines where you are going to install the server. Any machine with at least 512MB of RAM is fine. Of course you need to have more than one machine to have a cluster running.

2. Download Openfire from here

http://www.igniterealtime.org/downloads/

3. Run the installer to install Openfire in each of the machines. Follow the installation guide for more help.

http://www.igniterealtime.org/builds/openfire/docs/latest/documentation/install-guide.html

4. Start the server and complete the setup wizard in each machine. Make sure to use the same XMPP domain, an external database and that all servers are using the same database.

5. Download the Openfire Enterprise plugin from here

http://www.igniterealtime.org/projects/openfire/plugins.jsp

6. Log into the admin console and go to the Plugins page. Upload the enterprise.jar file from that page. Run this step for each machine.

7. Go to the Enterprise tab to enter a valid license for Openfire Enterprise.

At this point you have several machines running Openfire Enterprise. The last step is to enable clustering and see how the machines meet each other. Follow these steps to enable clustering:

1.Go to the clustering page in the admin console.

2. Click on Enabled clustering and save the settings. It will take a few seconds for the first machine to start the cluster. Enabling cluster in the other machines will be faster. As each node joins the cluster you will see in the clustering page the nodes that conform the cluster.

What's next?

You may want to use a load balancer to distribute load between active servers. The load balancer does not need to support sticky sessions since XMPP connections are longed lived.

Scraping an Entire Website using LINUX

2010-01-29T10:20:00.003+08:00

Web scraping (also called Web harvesting or Web data extraction) is a computer software technique of extracting information from websites. Usually, such software programs simulate human exploration of the Web by either implementing low-level Hypertext Transfer Protocol (HTTP), or embedding certain full-fledged Web browsers, such as the Internet Explorer (IE) and the Mozilla Web browser. Web scraping is closely related to Web indexing, which indexes Web content using a bot and is a universal technique adopted by most search engines. In contrast, Web scraping focuses more on the transformation of unstructured Web content, typically in HTML format, into structured data that can be stored and analyzed in a central local database or spreadsheet. Web scraping is also related to Web automation, which simulates human Web browsing using computer software. Exemplary uses of Web scraping include online price comparison, weather data monitoring, website change detection, Web research, Web content mashup and Web data integration. [wikipedia]

Scarping a website using wget command in Linux.

$ wget -m --tries=7 "http://www.linuxnuggetz.blogspot.com"

Spoofing the browser that you are using.

$ wget --user-agent="Mozilla 2.0" -m http://www.linuxnuggetz.blogspot.com

Changing Date and Time in Linux

2009-11-28T14:39:00.002+08:00

Syntex:
1. date -s "DD Mon YYYY hh:mm:ss"

2. date set="DD Mon YYYY hh:mm:ss"

3. date MMDDhhmmYYYY.ss

Example:
1. date -s "28 NOV 2008 13:45:00"

2. date set="28 NOV 2008 13:45:00"

3. date 112813452009

Setting Time in Linux

Syntex:
date +%T -s "hh:mm:ss"

Example:
date +%T -s "10:13:13"

Deleting Files/Folders based on OWNERSHIP

2009-11-04T11:41:00.007+08:00

1. List the files and directories.

$ ls -lah

total 52K
drwxrwxrwt 11 root root 4.0K Nov 4 03:52 .
drwxr-xr-x 25 root root 4.0K Oct 6 03:54 ..
srwxr-xr-x 1 george george 0 Oct 8 00:47 .dguardianipc
srwxr-xr-x 1 george george 0 Oct 8 00:47 .dguardianurlipc
-rw-r--r-- 1 root root 0 Nov 4 03:52 file1
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file2
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file3
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file4
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file5
-rw-r--r-- 1 root root 0 Nov 4 03:52 file6
-rw-r--r-- 1 root root 0 Nov 4 03:52 file7
drwxrwxrwt 2 root root 4.0K Oct 1 07:55 .font-unix
drwxrwxrwt 2 root root 4.0K Oct 1 07:55 .ICE-unix
drwxr-xr-x 2 root root 4.0K Nov 4 03:43 test1
drwxr-xr-x 2 root root 4.0K Nov 4 03:51 test2
drwxr-xr-x 2 root root 4.0K Nov 4 03:43 test[2-7]
drwxr-xr-x 2 root root 4.0K Nov 4 03:43 test2-7
drwxr-xr-x 2 george george 4.0K Nov 4 03:51 test3
drwxr-xr-x 2 george george 4.0K Nov 4 03:51 test4
drwxr-xr-x 2 george george 4.0K Nov 4 03:51 test5

2. Let's try deleting the files with an owner 'gopher'

List the files with gopher owner.

$ ls -lah | grep gopher

output:
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file2
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file3
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file4
-rw-r--r-- 1 gopher gopher 0 Nov 4 03:52 file5

The output are from file2 to file5, next task is to list the exact filenames using awk.

$ ls -lah | gopher | awk '{print $9}

Output:
file2
file3
file4
file5

Now that the output list only filenames, we can now delete the files.

$ rm -fv `ls -lah | grep gopher | awk '{print $9}'`

Output:
removed `file2'
removed `file3'
removed `file4'
removed `file5'

If its a directory you can issue this pattern:

$ rm -fvR `ls -lah | grep george | awk '{print $9}'`

Output:
removed directory: `test3'
removed directory: `test4'
removed directory: `test5'

Note: be sure to replace the 'grep (owner)' with the specified owner/user.

Easy way to extract Logs on a Date/Line Range in LINUX

2009-10-28T10:09:00.008+08:00

Example: range of date to be extracted in the /var/log/message. Oct 26-27
our x will be Oct 26, y will be Oct 27

1. Get the first line number which will be our x reference (x - Oct 26).

$ grep -n 'Oct 26' /var/log/messages | head

The initial reference of x = 29933

Sample Output:

29933:Oct 26 00:00:00 postfix nagios: LOG ROTATION: DAILY
29934:Oct 26 00:00:00 postfix nagios: LOG VERSION: 2.0
29935:Oct 26 00:00:00 postfix nagios: CURRENT HOST STATE: localhost;UP;HARD;1;PING OK - Packet loss = 0%
29936:Oct 26 00:00:00 postfix nagios: CURRENT SERVICE STATE: localhost;Current Load;OK;HARD;1;OK
29937:Oct 26 00:00:00 postfix nagios: CURRENT SERVICE STATE: localhost;Current Users;OK;HARD;1
29938:Oct 26 00:00:00 postfix nagios: CURRENT SERVICE STATE: localhost;HTTP;WARNING
29939:Oct 26 00:00:00 postfix nagios: CURRENT SERVICE STATE: localhost;PING;OK;HARD;1;PING OK - Packet loss = 0%
29940:Oct 26 00:00:00 postfix nagios: CURRENT SERVICE STATE: localhost;Root Partition;OK;HARD;1;DISK OK - free space
29941:Oct 26 00:00:00 postfix nagios: CURRENT SERVICE STATE: localhost;SSH;OK;HARD;1;SSH OK
29942:Oct 26 00:00:00 postfix nagios: CURRENT SERVICE STATE: localhost;Swap Usage;OK;HARD;1;

2. Get the last line number which will be our y reference (x - Oct 27).

$ grep -n 'Oct 27' /var/log/messages | tail

The last reference of y = 89712

Sample Output:

89703:Oct 27 23:59:14 postfix snmpd[18448]: -- IF-MIB::ifPhysAddress.1
89704:Oct 27 23:59:16 postfix snmpd[18448]: Connection from UDP: [192.168.0.x]:1055
89705:Oct 27 23:59:26 postfix last message repeated 15 times
89706:Oct 27 23:59:36 postfix snmpd[18448]: Connection from UDP: [192.168.0.131]:4118
89707:Oct 27 23:59:36 postfix snmpd[18448]: Received SNMP packet(s) from UDP: [192.168.0.x]:4118
89708:Oct 27 23:59:36 postfix snmpd[18448]: send response: Failure in sendto
89709:Oct 27 23:59:36 postfix snmpd[18448]: -- SNMPv2-MIB::sysObjectID.0
89710:Oct 27 23:59:36 postfix snmpd[18448]: -- IF-MIB::ifPhysAddress.1
89711:Oct 27 23:59:36 postfix snmpd[18448]: Connection from UDP: [192.168.0.x]:1055
89712:Oct 27 23:59:56 postfix last message repeated 23 times

3. Use the x,y reference to extract the file : x = 29933, y =89712

$ sed -n '29933,89712p' /var/log/messages > newfilename

Google Sitemap Generator Installation in a CentOS Platform

2009-09-06T20:35:00.005+08:00

1. Download Google Site Map Generator:

http://code.google.com/p/googlesitemapgenerator/downloads/list

2. Unpack the downloaded file

$ tar –zxvf sitemap_linux-i386-beta1-20090225.tar.gz

3. Run the installation script

$ cd sitemap-install/
$ ./install.sh -t /usr/sbin/apachectl -g apache

Other options:
* -h displays help about these command line options.
* -d directory specifies a non-default installation directory.
* -a Apache-binary-filename specifies the path to the Apache binary file (httpd).
Alternatively, you can specify this value during installation.
* -c Apache-config-filename specifies the Apache root configuration file.
* -g Apache-group specifies the user group name under which Apache is running.
* -t Apache-control-filename specifies the Apache control script (apache ctl).
If you specify this value, the installer lets you choose to automatically
restart Apache at the end of the installation.
If you omit this option, you'll need to restart Apache manually.

Just simply follow the installation, everything is interactive.

4. By default you can access the sitemap generator via port 8181

e.g. http://yourserver:8181/

5. Initialy you will be denied accessing it remotely. Run this in the terminal to enable remote access.

$ /usr/local/google-sitemap-generator/bin/sitemap-daemon remote_admin enable

6. Install SSL requirements.

$ yum install mod_ssl openssl

7. Generate a self-signed certificate

Generate private key
$ openssl genrsa -out ca.key 1024

Generate CSR
$ openssl req -new -key ca.key -out ca.csr

Generate Self Signed Key
$ openssl x509 -req -days 365 -in ca.csr -signkey ca.key -out ca.crt

Move the files to the correct locations
$ mv ca.crt /etc/pki/tls/certs
$ mv ca.key /etc/pki/tls/private/ca.key
$ mv ca.csr /etc/pki/tls/private/ca.csr

8. Then update the Apache SSL configuration file

$ vi +/SSLCertificateFile /etc/httpd/conf.d/ssl.conf

Comment the existing and add the following:

SSLCertificateFile /etc/pki/tls/certs/ca.crt
SSLCertificateKeyFile /etc/pki/tls/private/ca.key

Restart the apache server

$ /etc/init.d/httpd restart

9. Edit the sitemap generator httpd configuration.

$ vi /usr/local/google-sitemap-generator/conf/httpd.conf

Add the SSL lines, or you can simply paste the code below

Listen 8181
NameVirtualHost *:8181
<VirtualHost *:8181>
SSLEngine on
SSLCertificateFile /etc/pki/tls/certs/ca.crt
SSLCertificateKeyFile /etc/pki/tls/private/ca.key
DocumentRoot "/usr/local/google-sitemap-generator/admin-console"
ScriptAlias /cgi-bin/ "/usr/local/google-sitemap-generator/admin-console/cgi-bin/"

<Directory "/usr/local/google-sitemap-generator/admin-console" >
# Allow from all
AllowOverride All
Options ExecCGI
DirectoryIndex index.html
</Directory>
</VirtualHost>

LoadModule google_sitemap_generator_module "/usr/local/google-sitemap-generator/lib/mod_sitemap.so"

10. Restart Apache and that's It.

$ /etc/init.d/httpd restart

Starting and Stopping Google Sitemap Deamon

$ /usr/local/google-sitemap-generator/bin/sitemap-daemon service start
$ /usr/local/google-sitemap-generator/bin/sitemap-daemon service stop
$ /usr/local/google-sitemap-generator/bin/sitemap-daemon service restart

MySQL Commands - Adding User, Backup and Restore

2009-07-17T13:54:00.009+08:00

Adding new user to access the database

Syntax:
mysqldump -u [username] -p [password] [databasename] > [backupfile.sql]

Examples:
mysql> GRANT all ON mydatabase.* TO myuser@'192.168.17.186' IDENTIFIED BY 'mypassword';
mysql> GRANT all ON mydatabase.* TO myuser@'localhost' IDENTIFIED BY 'mypassword';
mysql> FLUSH PRIVILEGES;

Making Backup of the Database

Syntax:
mysqldump -u[mysqluser] -p[password] [databasename] > [destinationfile.sql]

Example:
$ mysqldump -utestaccount -pg3pass employeefile > employeefile-dump.sql

Restoring MySQL Database

$ mysql -uaccount -ppassword employeefile < employeefile-dump.sql

Making Backup of the existing Table

Syntax:
create table <Table Destination> as select * from <Table Source>;

Example:
create table RADUSAGE_09082009 as select * from RADUSAGE;

Killing a Process in Linux

2009-07-10T08:46:00.001+08:00

At times we encounter java process that won't stop by issuing the usual command "./shutdown.sh", or in some cases a multiple instance was created when the program was not properly restarted.

Below are the sample process status of the java in my linux box.

[root@geone bin]# ps -eaf | grep java
root 27272 1 0 Jul06 ? 00:00:22 /usr/java/j2sdk1.4.1_01/bin/java
root 27684 27273 0 Jul06 ? 00:03:01 /usr/java/j2sdk1.4.1_01/bin/java
root 27685 27273 0 Jul06 ? 00:04:23 /usr/java/j2sdk1.4.1_01/bin/java
root 27686 27273 0 Jul06 ? 00:03:01 /usr/java/j2sdk1.4.1_01/bin/java
root 27687 27273 0 Jul06 ? 00:03:01 /usr/java/j2sdk1.4.1_01/bin/java
root 27688 27273 0 Jul06 ? 00:03:04 /usr/java/j2sdk1.4.1_01/bin/java
root 27689 27273 0 Jul06 ? 00:03:04 /usr/java/j2sdk1.4.1_01/bin/java
root 27690 27273 0 Jul06 ? 00:03:04 /usr/java/j2sdk1.4.1_01/bin/java
root 27691 27273 0 Jul06 ? 00:03:01 /usr/java/j2sdk1.4.1_01/bin/java
root 27692 27273 0 Jul06 ? 00:03:01 /usr/java/j2sdk1.4.1_01/bin/java
root 27693 27273 0 Jul06 ? 00:03:02 /usr/java/j2sdk1.4.1_01/bin/java
root 27694 27273 0 Jul06 ? 00:03:01 /usr/java/j2sdk1.4.1_01/bin/java
root 27695 27273 0 Jul06 ? 00:03:04 /usr/java/j2sdk1.4.1_01/bin/java
root 2015 27273 0 Jul07 ? 00:00:00 /usr/java/j2sdk1.4.1_01/bin/java
root 2016 27273 0 Jul07 ? 00:00:00 /usr/java/j2sdk1.4.1_01/bin/java
root 2017 27273 0 Jul07 ? 00:00:00 /usr/java/j2sdk1.4.1_01/bin/java
root 2018 27273 0 Jul07 ? 00:00:00 /usr/java/j2sdk1.4.1_01/bin/java
root 2053 27273 0 Jul07 ? 00:00:00 /usr/java/j2sdk1.4.1_01/bin/java
root 2054 27273 0 Jul07 ? 00:00:00 /usr/java/j2sdk1.4.1_01/bin/java
root 2055 27273 0 Jul07 ? 00:00:02 /usr/java/j2sdk1.4.1_01/bin/java

root 2056 27273 0 Jul07 ? 00:00:00 /usr/java/j2sdk1.4.1_01/bin/java
root 24302 27273 0 Jul08 ? 00:03:00 /usr/java/j2sdk1.4.1_01/bin/java
root 24303 27273 0 Jul08 ? 00:03:00 /usr/java/j2sdk1.4.1_01/bin/java
root 24304 27273 0 Jul08 ? 00:02:59 /usr/java/j2sdk1.4.1_01/bin/java
root 24305 27273 0 Jul08 ? 00:02:58 /usr/java/j2sdk1.4.1_01/bin/java
root 24338 27273 0 Jul08 ? 00:02:58 /usr/java/j2sdk1.4.1_01/bin/java
root 24339 27273 0 Jul08 ? 00:02:59 /usr/java/j2sdk1.4.1_01/bin/java
root 24340 27273 0 Jul08 ? 00:02:58 /usr/java/j2sdk1.4.1_01/bin/java
root 24341 27273 0 Jul08 ? 00:02:59 /usr/java/j2sdk1.4.1_01/bin/java
root 24404 27273 0 00:06 ? 00:02:57 /usr/java/j2sdk1.4.1_01/bin/java

The best way to stop the process is to issue the command below:

$ kill -9 `ps -eaf | grep java | awk '{ print $2, $8}'`

A Note on Traffic Exchange Programs

2009-06-30T22:44:00.006+08:00

We understand that our publishers are always looking for ways to attract interested users to their sites. But using third-party tools or services to increase your site traffic may lead to invalid clicks or impressions and result in your account being disabled. For this reason, we'd like to provide you with some guidance about this.

As many of you already know, our program policies strictly prohibit any means of artificially generating ad impressions or clicks, including third-party services such as paid-to-click, paid-to-surf, auto-surf, and click-exchange programs. These programs offer incentives for users to view web pages or click on ads, resulting in activity that is harmful to our advertisers.

We occasionally receive questions from publishers interested in using traffic exchanges to bring traffic to their site. While these services may help advertise your site, we don't recommend using them, as they may also result in similar invalid activity. We realize that you may have questions about a specific traffic service and whether it could potentially create invalid impressions or clicks. However, please understand that we're unable to comment on any particular third-party service.

As a parting note, we encourage you to read through our tips and guidelines and Webmaster Guidelines to help keep your account in good standing. These guidelines advise publishers to "Provide unique and relevant content that gives users a reason to visit your site first," and we feel this is ultimately the best way to attract more visitors to your site and build a truly loyal audience.

Adsense Blog

Setting-up Nagios in Ubuntu

2009-06-30T12:04:00.005+08:00

1. Overview
Nagios is a powerful tool that provides you with instant awareness of your organization's mission-critical IT infrastructure. Nagios allows you to detect and repair problems and mitigate future issues before they affect end-users and customers.

2. Platform
Ubuntu (Desktop) 8.04 Hardy Heron

Username : nagios
Password : "password"

Nagios Version 3.0.3
Nagios Plugin 1.4.13
Nagios NRPE Plugins 2.12 (For clients / Hosts)
NSClient++ Win32-0.3 (For Clients / Hosts)

3. Installation
3.1. Nagios Server
3.1.1. Required Packages

Make sure you've installed the following packages on your Ubuntu installation before continuing.
Apache 2
GCC compiler and development libraries
GD development libraries
You can use apt-get to install these packages by running the following commands:

$ sudo apt-get install apache2
$ sudo apt-get install build-essential
$ sudo apt-get install libgd2-xpm-dev

3.1.2. Account Information

Become the root user.
$ sudo -s

Create a new nagios user account and give it a password.
$ /usr/sbin/useradd -m nagios
$ passwd nagios

Create a new nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user to the group.
$ /usr/sbin/groupadd nagcmd
$ /usr/sbin/usermod -G nagcmd nagios
$ /usr/sbin/usermod -G nagcmd www-data

3.1.3 Download Nagios and the Plugins

Create a directory for storing the downloads.
$ mkdir ~/downloads
$ cd ~/downloads

Download the source code tarballs of both Nagios and the Nagios plugins (http://www.nagios.org/download/). At the time of writing, the latest versions of Nagios and the Nagios plugins were 3.0.3 and 1.4.13, respectively.

$ wget http://osdn.dl.sourceforge.net/sourceforge/nagios/nagios-3.0.3.tar.gz
$ wget http://osdn.dl.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.13.tar.gz

3.1.4 Compile and Install Nagios
Extract the Nagios source code tarball.

$ cd ~/downloads
$ tar xzf nagios-3.0.3.tar.gz
$ cd nagios-3.0.3

Run the Nagios configure script, passing the name of the group you created earlier like so:
$ ./configure --with-command-group=nagcmd

Compile the Nagios source code.
$ make all

Install binaries, init script, sample config files and set permissions on the external command directory.
$ make install
$ make install-init
$ make install-config
$ make install-commandmode

3.1.5. Customize Configuration
Sample configuration files have now been installed in the /usr/local/nagios/etc directory. These sample files should work fine for getting started with Nagios. You'll need to make just one change before you proceed.

Edit the /usr/local/nagios/etc/objects/contacts.cfg config file with your favorite editor and change the email address associated with the nagiosadmin contact definition to the address you'd like to use for receiving alerts.

$ vi /usr/local/nagios/etc/objects/contacts.cfg

3.1.6 Configure the Web Interface
Install the Nagios web config file in the Apache conf.d directory.
$ make install-webconf

Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account - you'll need it later.
$ htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

Username : nagiosadmin
Password : "password"

Restart Apache to make the new settings take effect.
$ /etc/init.d/apache2 reload

3.1.7. Compile and Install the Nagios Plugins
Extract the Nagios plugins source code tarball.

$ cd ~/downloads
$ tar xzf nagios-plugins-1.4.13.tar.gz
$ cd nagios-plugins-1.4.13

Compile and install the plugins.
$ ./configure --with-nagios-user=nagios --with-nagios-group=nagios
$ make
$ make install

3.1.8. Start Nagios
Configure Nagios to automatically start when the system boots.
$ ln -s /etc/init.d/nagios /etc/rcS.d/S99nagios

Verify the sample Nagios configuration files.
$ /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

If there are no errors, start Nagios.
$ /etc/init.d/nagios start

3.1.9. Login to the Web Interface
You should now be able to access the Nagios web interface at the URL below. You'll be prompted for the username (nagiosadmin) and password you specified earlier.
http://localhost/nagios/ or
http://192.168.0.236/nagios
Click on the "Service Detail" navbar link to see details of what's being monitored on your local machine. It will take a few minutes for Nagios to check all the services
associated with your machine, as the checks are spread out over time.

3.1.10 Other Modifications (Not yet implemented)
If you want to receive email notifications for Nagios alerts, you need to install the mailx (Postfix) package.
$ sudo apt-get install mailx

You'll have to edit the Nagios email notification commands found in /usr/local/nagios/etc/objects/commands.cfg and change any '/bin/mail' references to '/usr/bin/mail'. Once you do that you'll need to restart Nagios to make the configuration changes live.
$ sudo /etc/init.d/nagios restart

Configuring email notifications is outside the scope of this documentation. Refer to your system documentation, search the web, or look to the http://www.nagioscommunity.org/wiki for specific instructions on configuring your Ubuntu system to send email messages to external addresses.

Credits to :
Eman Bolivar (fellow Systems Admin)

Linux 2.6.30 Gets New Filesystems

2009-06-29T15:37:00.004+08:00

Article Source : Desktop Linux

Linus Torvalds (pictured) announced Linux kernel 2.6.30, adding several new filesystems, including the NILFS2 log-structured filesystem. Linux 2.6.30 enhancements include a local caching layer for NFS data, the RDS server cluster communications protocol, the Tomoyo security module, and support for LZMA and BZIP2 compression algorithms.

The 2.6.30 release arrives less than three months after Linux kernel 2.6.29, which added a wide variety of driver and header updates, WiMAX support, the embedded-oriented Squashfs filesystem, and a preliminary new Btrfs filesystem. The new kernel release further feeds Linux developers' insatiable appetite for new filesystems.

The new NILFS2 treats the whole disk as a consecutive list of blocks (or "log"), and never rewrites blocks. As a result, all modifications and creations are converted into sequential operations, which are said to be faster. Other NILFS2 improvements are said to include the ability to offer a more coherent historical view of operations, called "continuus snapshotting," enabling users to restore files that have been mistakenly destroyed only a few seconds previously.

Read rest of the article at DesktopLinux

First Major PHP Update in Years Coming Soon

2009-06-29T15:26:00.005+08:00

Thursday, 25 June 2009 17:07

Article Source internetnews.com

PHP 5.3 could be out as soon as Tuesday, June 30th. The new open source language release is a big deal for a lot of reasons, not the least of which is the fact that by my count this is the first major update to PHP since 2006 and the PHP 5.2 release.

PHP 5.3 is also interesting in that it includes at least one key feature that was originally intended for PHP 6 (whenever -- if ever -- that release will be out).

I spoke with Zeev Suraski, co-founder and CTO at commercial PHP vendor Zend Technologies last month about PHP 5.3. He noted that one key feature backported from PHP 6 into PHP 5.3 is namespaces, which is a way to encapsulate classes and other PHP items more easily.

Read rest of the content at Internetnews

Opera Kicks It Up A Notch With Unite

2009-06-29T15:21:00.001+08:00

Article Source Linux Magazine
June 26, 2009, 5:22 am

A few weeks ago I took Opera 10 beta for a test drive to see if the Opera folks had a shot at claiming serious share on the desktop. While Opera 10 is the best Opera release yet, it didn’t seem to have any killer features that would drive adoption. Last week, Opera pulled the other one and released Opera Unite: the killer feature that might put Opera over the top...

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Script in Monitoring Your LINUX Server

2009-06-19T12:55:00.018+08:00

You can use this as pattern in monitoring you server.

1. Create a file "system-check.sh" and paste the code below:
(this will monitor - apache, java, postfix, mail que, mysql and failed logins)

echo
echo "youserver.com.ph"
date
echo
vmstat 5 5|awk -F" " '{print $4" "$5" "$8" "$16}'
echo ---------------------------------
df -k
echo ---------------------------------
ps -eaf | grep httpd
echo ---------------------------------
ps -eaf | grep java
echo ---------------------------------
ps -eaf | grep postfix
echo ---------------------------------
ps -eaf | grep -c smtp
echo ---------------------------------
ps -eaf | grep mysql
echo ---------------------------------
lastb | head

_______________
Note:
you can add a service check by changing syntax below:

ps -eaf | grep <service>
e.g. ps -eaf | grep named

Checking logs:
tail /usr/local/apache/logs/error_log

2. Create a file "system-check.cron" and insert the code below:

#! /bin/sh

a=`eval date +%m'/'%d'/'%Y`

clear
echo
nice system-check.sh > result.txt

mail -s SERVERNAME-$a youremail@com.ph < result.txt

3. Add this in the crontab, this will initiate routine check every 6am, 2pm, and 10pm, and sends you an and email result.

0 6,14,22 * * * /root/scripts/routines.cron > /dev/null 2>&1

Ruby on Rails in Ubuntu

2009-06-11T13:52:00.016+08:00

Install the Dependencies:
Build-essentials

Ruby:
$ wget ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.1-p129.tar.gz
$ tar -xzvf ruby-1.9.1-p129.tar.gz

change directory to the extracted directory

$ sudo ./configure
$ sudo make
$ sudo make install

RubyGems:
$ wget http://rubyforge.org/frs/download.php/57643/rubygems-1.3.4.tgz
$ tar -xzvf rubygems-1.3.4.tgz

change directory to the extracted directory

$ sudo ruby setup.rb
$ gem -v

Rails:
$ sudo gem install rails --include-dependencies

Terminal Output:
INFO: `gem install -y` is now default and will be removed
INFO: use --ignore-dependencies to install only the gems you list
Successfully installed rake-0.8.7
Successfully installed activesupport-2.3.2
Successfully installed activerecord-2.3.2
Successfully installed actionpack-2.3.2
Successfully installed actionmailer-2.3.2
Successfully installed activeresource-2.3.2
Successfully installed rails-2.3.2
7 gems installed
Installing ri documentation for rake-0.8.7...
Installing ri documentation for activesupport-2.3.2...
Installing ri documentation for activerecord-2.3.2...
Installing ri documentation for actionpack-2.3.2...
Installing ri documentation for actionmailer-2.3.2...
Installing ri documentation for activeresource-2.3.2...
Installing ri documentation for rails-2.3.2...
Updating class cache with 1382 classes...
Installing RDoc documentation for rake-0.8.7...
Installing RDoc documentation for activesupport-2.3.2...
Installing RDoc documentation for activerecord-2.3.2...
Installing RDoc documentation for actionpack-2.3.2...
Installing RDoc documentation for actionmailer-2.3.2...
Installing RDoc documentation for activeresource-2.3.2...
Installing RDoc documentation for rails-2.3.2...

List the installed gem files
$ gem list --local

Create the Web Directory
$ cd /var/www
$ sudo mkdir rubyweb
$ cd rubyweb/
$ sudo rails myweb

Running RoR for the first time:
$ ruby script/server
___
/usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.2/lib/initializer.rb:269:in `rescue in require_frameworks': no such file to load -- openssl (RuntimeError)
from /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.2/lib/initializer.rb:266:in `require_frameworks'
from /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.2/lib/initializer.rb:134:in `process'
from /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.2/lib/initializer.rb:113:in `run'
from /var/www/rubyweb/myweb/config/environment.rb:9:in `<top (required)>'
from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:156:in `require'
from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:156:in `block in require'
from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:521:in `new_constants_in'
from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:156:in `require'
from /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.2/lib/commands/server.rb:84:in `<top (required)>'
from script/server:3:in `require'
from script/server:3:in `<main>'

If you encounter the above error, run the following to fix the error

$ sudo apt-get install openssl libssl-dev
$ sudo apt-get install ruby1.9-dev
$ cd /usr/src/ruby-1.9.1-p129/ext/openssl
$ sudo ruby extconf.rb
$ sudo make && make install

Run the server again.
$ cd /var/www/rubyweb/myweb
$ ruby script/server

Ruby on Rails with Mongrel Clusters Connecting to Oracle Database

2009-06-11T11:32:00.012+08:00

Note:
First disable selinux.
to check the config edit "/etc/sysconfig/selinux", if you made changes reboot the system.

Install the dependencies:

Development Libraries:
$ yum -v groupinstall "Development Libraries"
$ yum -v groupinstall "Development Tools"

Zlib:
$ yum install zlib zlib-devel

Readline:
$ yum install readline-devel

Freeimage:
$ wget http://nchc.dl.sourceforge.net/sourceforge/freeimage/FreeImage3120.zip
$ unzip FreeImage3120.zip
$ make
$ make install

1. Download and install Ruby 1.8.6 patch 111

Ruby download site : http://www.ruby-lang.org/en/downloads/

$ wget ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.6-p111.tar.gz
$ tar xzvf ruby-1.8.6-p111.tar.gz
$ cd ruby-1.8.6-p111
$ ./configure
$ make
$ make install

Try checking the version if the installation goes well

$ ruby -v

Output:
ruby 1.8.6 (2007-09-24 patchlevel 111) [i686-linux]

2. Download and install Gem 1.0.1

$ wget http://rubyforge.org/frs/download.php/29548/rubygems-1.0.1.tgz
$ tar xzvf rubygems-1.0.1.tgz
$ cd rubygems-1.0.1
$ ruby setup.rb

Do a version check again
$ gem -v

Output:
1.0.1

Install Rails 2.0.2 using the following command:

$ gem install rails -v 2.0.2 - (this would take time to install, in my test pc PentIII it took more than 2hrs)

3. Register to Oracle and download the following Oracle clients:

oracle-instantclient-basic-10.2.0.3-1.i386.rpm
oracle-instantclient-basic-10.2.0.3-1.i386.rpm
oracle-instantclient-sqlplus-10.2.0.3-1.i386.rpm

$ rpm -ivh oracle-instantclient-basic-10.2.0.3-1.i386.rpm
$ rpm -ivh oracle-instantclient-basic-10.2.0.3-1.i386.rpm
$ rpm -ivh oracle-instantclient-sqlplus-10.2.0.3-1.i386.rpm

* run and add this in the /etc/profile

$ LD_LIBRARY_PATH=/usr/lib/oracle/10.2.0.3/client/lib
$ export LD_LIBRARY_PATH

5. Download and install Ruby-OCI8

Download from http://rubyforge.org/frs/download.php/28396/ruby-oci8-1.0.0.tar.gz
Uncompress and extract the file contents.
Execute the following from within the extracted directory:

ruby setup.rb

* (Rails installation has to be finished before this) Copy the Oracle Adapter to the correct directory:

cp /path/to/oracle_adapter.rb /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/ (directory might be different on different installations, just search for active_record/connection_adapters)

6. Install other Ruby gems:

$ gem install mongrel
$ gem install mongrel_cluster
$ gem install ruby-debug
$ gem install soap4r -v 1.5.7
$ gem install image_science

7. Install apache using yum.

$ yum install httpd

* Configure Apache. Your httpd.conf needs a configuration like that of below:

<Proxy balancer://test>
BalancerMember http://127.0.0.1:3000
BalancerMember http://127.0.0.1:3001
BalancerMember http://127.0.0.1:3002
</Proxy>
<VirtualHost *:80>
ServerAdmin testaccount@gmail.com
ServerName test.com
ServerAlias test
ProxyPass / balancer://test/
ProxyPassReverse / balancer://test/
ErrorLog /var/log/apache_error_log
CustomLog /var/log/apache_access_log combined
</VirtualHost>

* replace test and testaccount base on your server details

Implementing Subversion - CentOS

2009-06-06T20:14:00.012+08:00

Note: Apache is a requirement in setting up the Subversion.

1. Installing subversion.

$ yum install mod_dav_svn subversion

2. Configuring subversion's apache.

$ nano /etc/httpd/conf.d/subversion.conf

Make sure that these are loaded:

# Make sure you uncomment the following if they are commented out
LoadModule dav_svn_module modules/mod_dav_svn.so
LoadModule authz_svn_module modules/mod_authz_svn.so

# Add this directive

<Location /repos>
DAV svn
SVNPath /var/www/svn/repos
AuthType Basic
AuthName "Subversion repos"
AuthUserFile /etc/svn-auth-conf
Require valid-user
</Location>

3. Create an SVN user.

$ htpasswd -cm /etc/svn-auth-conf svnuser

4. Configure the repository.

$ cd /var/www/ (or the default apache web folder)
$ mkdir svn
$ cd svn
$ svnadmin create repos
$ chown -R apache.apache repos
$ service httpd restart

5. Accessing the URL using a browser.

http://serversIPorDomain/repos or http://192.168.0.xxx/repos

ref : wiki centos

ProFTPD and VSFTPD Server Installation

2009-06-06T19:20:00.025+08:00

Vsftpd installation and simple configuration - CentOS 5.2

1. Install the package via yum.

$ yum install vsftpd.i386

2. The default configuration is located at /etc/vsftpd/vsftpd.conf, edit and apply configurations below.

# Allow anonymous FTP?
anonymous_enable=NO

# Uncomment this to allow local users to log in.
local_enable=YES

# Uncomment this to enable any form of FTP write command.
write_enable=YES

# Add this line to jail users on their home directories.
chroot_local_user=YES

3. Start VSFTPD

$ /etc/init.d/vsftpd start

Proftpd Vsftpd installation and simple configuration - CentOS 5.2

1. Login as root, download and install the package:

$ wget http://software.virtualmin.com/gpl/centos/5.2/i386/proftpd-1.3.0a-3.el4.i386.rpm
$ rpm -ivh proftpd-1.2.10-1.fc1.i386.rpm

2. The default configuration can be found at /etc/proftpd.conf, edit and apply configurations below.

ServerType standalone
DefaultServer on

# Use this to excude users from the chroot
DefaultRoot ~ !adm

# Use pam to authenticate (default) and be authoritative
AuthPAMConfig proftpd
AuthOrder mod_auth_pam.c* mod_auth_unix.c

# Port 21 is the standard FTP port.
Port 21

# Umask 022 is a good standard umask to prevent new dirs and files
# from being group and world writable.
Umask 022

# To prevent DoS attacks, set the maximum number of child processes
# to 30. If you need to allow more than 30 concurrent connections
# at once, simply increase this value. Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
MaxInstances 20

3. To start the daemon, run:
$ /etc/init.d/proftpd start

Other daemon commands:
$ /etc/init.d/proftpd stop
$ /etc/init.d/proftpd reload
$ /etc/init.d/proftpd restart

4. To automatically start ProFTPD during bootup.
$ chkconfig --level 3 proftpd on

Adding Swap File to Currently Installed Ubuntu OS

2009-05-29T16:57:00.023+08:00

1. Create a file with a size you prefer.

# sudo dd if=/dev/zero of=/mnt/512Mb.swap bs=1M count=512

2. Format the created file

# sudo mkswap /mnt/512Mb.swap

3. Add the swap to the running system.

# sudo swapon /mnt/512Mb.swap

to check if the swap file has been activated use # cat /proc/meminfo or # free -t

4. To make the swap permanent every other boot.

# gksudo gedit /etc/fstab

Add the line at the end of the file

/mnt/512Mb.swap none swap sw 0 0

5. Save and reboot the system.

source: help.ubuntu

Testing Radiator Radius via PHP Client

2009-05-13T19:12:00.027+08:00

1. Install Apache and PHP with radius module.

reference :
http://freeradius.org/mod_auth_radius/

(XAMPP Package has pre-installed radius module, you can use this for alternative installation)

2. Create a PHP script for the authentication test, use the content below.

<html>
<head><title>RSA Test</title></head>
<body bgcolor=#ffc7 text=#000000>
<?php
$challenge = false;
$loginAccepted = false;
$error = false;

if (isset($_POST['uname'])) {
$radius = radius_auth_open();

if (!radius_add_server($radius,'[IP ADDRESS]',[PORT],'[secret]',60,1)) {
$error = radius_strerror($radius);
} else if (!radius_create_request($radius,RADIUS_ACCESS_REQUEST)) {
$error = radius_strerror($radius);
} else {

radius_put_attr($radius,RADIUS_USER_NAME,$_POST['uname']);
if (isset($_POST['challenge'])) {
radius_put_attr($radius,RADIUS_USER_PASSWORD,$_POST['challenge']);
radius_put_attr($radius, RADIUS_STATE, $_POST['state']);
} else {
radius_put_attr($radius,RADIUS_USER_PASSWORD,$_POST['upw']);
}

$result = radius_send_request($radius);
if ($result == RADIUS_ACCESS_ACCEPT) {
$loginAccepted = true;

} else if ($result == RADIUS_ACCESS_REJECT) {
$loginAccepted = false;

} else if ($result == RADIUS_ACCESS_CHALLENGE) {
// When we get a challenge, return the response as the password
// and return RADIUS_STATE as given

$challenge = true;
$challengePrompt = false;
$challengeState = false;
$challengeStatus = false;

// loop through attributes.
while ($attrArray = radius_get_attr($radius)) {
if (!is_array($attrArray)) break;
if ($attrArray['attr'] == RADIUS_REPLY_MESSAGE) $challengePrompt =
$attrArray['data'];
if ($attrArray['attr'] == RADIUS_STATE) {
$challengeState = false;
$parts = explode('|', $attrArray['data']);
if (sizeof($parts) == 2) {
if (strlen($parts[0]) == 12) {
if (strcmp(substr($parts[0], 0, 8), "SECURID_") == 0) {
$challengeStatus = substr($parts[0], 8);
$challengeState = $attrArray['data'];
}
}
}
}
}
if ($challengePrompt === false) $error = "Error receiving challenge prompt";

} else {
$error = radius_strerror($radius);
}
}
if ($error !== false) {
print "There was an error trying to authenticate.<br>";
print "<i>" . $error . "</i><br>";
print "<hr>";
}
}
?>

<?
if ($challenge && (strcmp($challengeStatus, "WAIT") != 0)) {
print "<h1>SecurID Challenge</h1>";
} else if ($challenge && (strcmp($challengeStatus, "WAIT") == 0)) {
print "<h1>SecurID Response Accepted</h1>";
print "<h3>" . $challengePrompt . "</h3>";
} else if ($loginAccepted) {
print "<h1>SecurID Login Accepted</h1>";
// header("location: http://www.eyp.ph/hotspot");
} else if (!isset($_POST['uname'])) {
print "<h1>Radiator Radius Web Client</h1>";
} else {
print "<h1>SecurID Login Failure</h1>";
print "<h3>Please try again</h3>";
print "<em>(if after two tries, you're still getting a failure, try just your token code)</em>";
}
?>

<form action=<? print $_SERVER['PHP_SELF']; ?> method=POST>
Username: <input type=text name=uname size=30 value=""><br><br>




<? if (!$challenge || (strcmp($challengeStatus, "WAIT") == 0) || ($error !== false)) { ?>
Password: <input type=password name=upw size=30 value=""><br>
<? } else { ?>
<hr><? print $challengePrompt; ?><br>
Response: <input type=password name=challenge size=30 value=""><br>
<input type=hidden name=state value="<? print addslashes($challengeState); ?>">
<hr>
<? } ?>
<input type=submit name=submit value="Log In">
</form>
</body>
</html>

3. Find the line below and supply the IP Address, Port, and Secret of the radius server.

if (!radius_add_server($radius,'[IP ADDRESS]',[PORT],'[secret]',60,1)) {

4. Put the file in your apache web folder e.g. "/var/www/html"

5. You can now do the test via web e.g. "http://ipaddress/filename.php or http://server.com/filename.php"

Radiator Radius Installation connecting to ORACLE (CentOS)

2009-04-26T13:29:00.035+08:00

1. Download and install the Oracle client connectors.

http://www.oracle.com/index.html

oracle-instantclient-basic-10.2.0.3-1.i386.rpm
oracle-instantclient-devel-10.2.0.3-1.i386.rpm
oracle-instantclient-sqlplus-10.2.0.3-1.i386.rpm

rpm -Uvh oracle-instantclient-basic-10.2.0.3-1.i386.rpm
rpm -Uvh oracle-instantclient-devel-10.2.0.3-1.i386.rpm
rpm -Uvh oracle-instantclient-sqlplus-10.2.0.3-1.i386.rpm

2. Set the environment variables.

# ORACLE_HOME=/usr/lib/oracle/10.2.0.3/client/lib
# export ORACLE_HOME
# export LD_LIBRARY_PATH=$ORACLE_HOME

# TNS_ADMIN=/usr/lib/oracle/10.2.0.3/client/admin
# export TNS_ADMIN

# mkdir /usr/lib/oracle/10.2.0.3/client/admin

3. Edit /etc/profiles and insert the lines below.

ORACLE_HOME=/usr/lib/oracle/10.2.0.3/client/lib
export ORACLE_HOME
export LD_LIBRARY_PATH=$ORACLE_HOME

TNS_ADMIN=/usr/lib/oracle/10.2.0.3/client/admin
export TNS_ADMIN

4. Create a file "tnsnames.ora" and insert the settings below.

SERVER1=
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = xxx.xxx.xxx.xxx)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = orcl)
)
)

5. Install Mysql Server for internal testing.

# yum install mysql-server.i386

this will install the following, and perl-DBI as well which you will need
as dependencies for Perl-Oracle-DBD.

============================
Package Arch Version Repository Size
============================
Installing:
mysql-server i386 5.0.45-7.el5 base 9.7 M

Installing for dependencies:
mysql i386 5.0.45-7.el5 base 4.1 M
perl-DBD-MySQL i386 3.0007-1.fc6 base 147 k
perl-DBI i386 1.52-1.fc6 base 605 k

6. Now we need to install Perl DBD Oracle Connector:
(note: you may need to install other dependencies
to make the configuration work)

a. Login as root

b. Create a temporary directory

# mkdir tempDBD
# cd tempDBD

c. gunzip/untar the DBD module

# gunzip DBD-Oracle-1.16.tar.gz
# tar -xvf DBD-Oracle-1.16.tar
# cd DBD-Oracle-1.16

d. Make/Install DBD

# perl Makefile.PL
# make
# make install

e. Remove temporary DBD directory and files

# cd ../..
# rm -rf tempDBD

7. To test if it is working run the following:

Make a pl file containig the line below
(replace the actual user and password).

use strict;
use DBI;

my $dbh = DBI->connect( 'dbi:Oracle:SERVER1',
'username',
'password',
{
RaiseError => 1,
AutoCommit => 0
}
) || die "Database connection not made: $DBI::errstr";
$dbh->disconnect();

8. Or run a direct connection to oracle.

# sqlplus /@SID

e.g. sqlplus username@password/SERVER1

If both connection doesn't have error connecting to Oracle Server, everything goes well.

__________________________
Download Reference:

DBI-1.48.tar.gz
http://www.idevelopment.info/data/Oracle/DBA_tips/support_data/DBI_DBD/DBI-1.48.tar.gz

DBD-Oracle-1.16.tar.gz
http://www.idevelopment.info/data/Oracle/DBA_tips/support_data/DBI_DBD/DBD-Oracle-1.16.tar.gz

ref: (for installation instruction)
http://www.idevelopment.info/data/Oracle/DBA_tips/Programming/PROGRAMMING_2.shtml
http://search.cpan.org/search?query=DBD::Oracle

9. Install the radiator rpm package.

# useradd radiusd
# groupadd radiusd

# rpm -Uvh Radiator-4.3.1-1.noarch.rpm

10. Install Radmin a radius web control center.

(Note : Install first the Apache2 server)

# tar xzvf Radmin-1.11.tgz

# cd Radmin-1.11

# sh installMysql.sh ("for Mysql") or # sh installOracle.sh (for Oracle)
note : you need to edit content of the .sh file based from the
account you have for the database server .e.g username, password, etc.

# perl install.pl

11. Edit radmin.cfg located in /etc/radiator

12. To start it run "/etc/init.d/radiator start"