NetBeans - Development Simplified

A free, open-source Integrated Development Environment for software developers. You get all the tools you need to create professional desktop, enterprise, web, and mobile applications with the Java language, C/C++, and even dynamic languages such as PHP, JavaScript, Groovy, and Ruby. NetBeans IDE is easy to install and use straight out of the box and runs on many platforms including Windows, Linux, Mac OS X and Solaris.

The NetBeans IDE 6.5 provides several new features and enhancements, such as rich PHP, JavaScript and Ajax editing features, improved support for using the Hibernate web framework and the Java Persistence API, and tighter GlassFish v3 and MySQL integration.

NetBeans IDE Installation Guide


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Meetings Events Conferences TOOL

The Indico tool allows you to manage complex conferences, workshops, and time-tables of meetings, to attach multimedia files to each event item and to store the resulting agendas in a multi-level hierarchical tree. Install the Indico software locally under GNU General Public License (see the project web site).

What is EGroupware?

EGroupware is a free enterprise ready groupware software for your network. It enables you to manage contacts, appointments, todos and many more for your whole business.

limitipconn module For Apache ( Debian GNU/Linux)

Use limitipconn module to limit maximum connections to web site.

step 1) Install apache2-mod-limitipconn_0.22-1_i386 module

step 2) limitipconn is enabled in mod_enabled and following lines are added in the apache2.conf file.

< IfModule mod_limitipconn.c >
< Location / >
MaxConnPerIP 5
# exempting images from the connection limit is often a good
# idea if your web page has lots of inline images, since these
# pages often generate a flurry of concurrent image requests
NoIPLimit image/*
< /Location >
< /IfModule >

Virtualization, RHEL 5.1

RHEL 5.1 will bring hardware virtualization feature improvements, paravirtualized drivers, the Xen 3.0.5 hypervisor and features like non-uniform memory access (NUMA) topology and loopback removal. Also, 5.1 will support live moves of virtual machines in clusters, along the lines of the functionality of VMware's VMotion.

Users of older versions of Red Hat are not being left out of the virtualization loop. Red Hat added some Xen support features to Red Hat Enterprise Linux 4.5.


The 4.5 option will have limitations. RHEL 4.5 includes virtualization support, so you have the choice of full virt or paravirt. Anything prior to RHEL 4.5 will run out of the box but will need full virtualization. You'll need a new chip. You don't have to touch the code, but you won't get the performance you get with RHEL 5.

VMware is way ahead of all the others in features and robustness, but VMware doesn't have a product that scales well. There are definitely limitations in high-availability, so most people are just virtualizing file servers at this point and not databases and performance-intensive apps.

To get the most out of RHEL 5's virtualization support options, these recommendations:

* Secure RHEL 5 platform layer before installing any virtual machines or applications.
* Run SELinux to run in enforcing mode.
* Remove or disable any unwanted services, like AutoFS, NFS, FTP, WWW, NIS, telnetd, sendmail and so on.
* Only add the minimum number of user accounts needed for platform management.
* Avoid running applications on dom0/Hypervisor, because running apps in dom0 may impact virtual machine performance.
* Use a central location for a virtual machine installation, which will make it easier to move to shared storage later on.

Postfix(MTA) appln corrupt ( OS: RHEL4)

If your postfix (MTA) stopped working or corrupt and not sure how to upgrade or downgrade it for better performance???

Here follows the solution for that :

step 1 : Query installed appln to know version details ( use following command )

command # rpm -qi postfix

step 2: Search for updated RPM of Postix ( if have subscription use www.rhn.redhat.com) and download to local machine

step 3: Query to list postfix related files using following command as a root

command# rpm -ql postfix

step 4: better backup files ( output of above command ) which are essential like, Configuration files /etc/postfix and mail queue /var/spool/postfix using command {cp -a source destination}

step 5: simulate RPM package installation before installing to machine. This will help to identify dependances error and file conflicts error.

command # rpm -Uvh --test postfix-2.2.x-RHEL.rpm

step 6: If found no error on above command , Now you can go for installing RPM using following command

command # rpm -Uvh postfix-2.2.x-RHEL.rpm

step 7 : To release mail queue built on the system when MTA was corrput. we need to requeue mails to flow again by following command

command # postsuper -r ALL

step 8 : Give a look on maillog to check for mail delivery to domain.

command #tail -f /var/log/maillog

Note : if you want to downgrade MTA, use this command instead of step 5 and rest of steps are same.

command # rpm -Uvh --test --oldpackage postfix-2.2.x-RHEL.rpm

command # rpm -Uvh --oldpackage postfix-2.2.x-RHEL.rpm

Troubleshooting Tools: Diagnosis DNS

In this Troubleshooting Tools for DNS, Given a record name, and a record type, you will receive a report detailing all possible answers. This is accomplished by traversing the DNS tree from the root examining all possible routes that a client could travel, calculating percentage probabilities on the way.

Visit squish.net DNS checker... :http://www.squish.net/dnscheck/