1. Adobe Flex SDK Opensource website

Adobe Flex SDK opensource website, where you can find all the documentation, SDK downloads of differenent versions, forums, and source code etc.

2. Adobe Flex Official Documetation

This link directly points to Flex documentation, this page has documentation for different Flex versions

Server Tomcat v5.5 Server at localhost failed to start.

And I was trying to find the reason for failing, and want to see the eclipse error logs. At this point of time I was not very sure about where the logs are kept for eclipse internal errors or eclipse exception stack trace. Then tried looking here and there in the eclipse, and finally found.

1. Go to the pulg-in development perspective from open perspective at top right side.
2. Then you would be able to see Error log tab at bottom side of eclipse.
3. In Error log tab you can find the all eclipse errors.
4. Double click on the error to see more information

You can also do below to see the Error log tab
Go to Window --> Show view --> General --> Error log

To see more detailed error log information about eclipse internal errors or eclipse plug-in errors go to your {workspace-folder}/.metadata/.log file.

Usually, this kind of behaviour occurs when one of the following happens

1. When user make a request, and suddenly browser get closed by user accidentally or due to browser crash
2. When user make a request, and browser closes the http connection automatically due to exceeded content length size
3. When user make a request, and presses the stop button

But surprisingly, there is one more reason which may cause this  problem. This is more unpredictable and very difficult to identify as well, that is problem with firewall.  When googled, I founded people complaining about firewall closing database connection automatically.  On top of this I am also not getting proper java exception stacktrace to track the error and fix.

To elaborate more on firewall issue, the error is more TCP/IP connection level error where database is closed by the firewall after database connection are idle for certain time or certain db connection length. Possibility is that there is a statefull firewall which is closing database connections after certain time limit. I am still in the process of identifying what could be the real problem. Once I found real probelm and solution, I will post it in here. If any one know the solutions, please post it in the comments section. Thank you.

Here is the command which list all the installed rpm software packages..

This command lists the installed rpm packages in less linux shell text editor, it will show few at a time, to see more just keep pressing enter button on your keyboard.

To see specific rpm software package like mysql or python, run below command

To list the rpm packages in sorted manner, run below command

I hope these commands may help in finding installed rpm packages. For any help email me or give a comment below in the comment box.

Below is the command used for finding centOS linux version

Same command in generic way for any linux machine

One more alternative command to see rpm based Linux versions, and also this command list all the rpm packages installed and their version numbers.

rpm -qa | grep centos

From now, If I forget this command, I can refer back here. Bravo!

So, while sending email using python smtplib library, I was getting smtplib.SMTPServerDisconnected error. It was working absolutely well before, I was wondering why the SMTPServerDisconnected error was coming now…

Error log

Above smtp instance variable is created without SMTP connection, so when I was calling smtp.sendmail() method python smtp lib was throwing that error.

To fix it,  I provided correct SMTP host/ip address, and also added error handling code to gracefully handle that error condition and log error message in log file.

Below is the fix

I know this very basic part of python smtp module, hope this may help python freshers. Any comments or feedback are welcome.

1. Good luck, Good fortune
2. Good luck in making fortune discoveries by accident.
3. Making fortune discoveries accidentally by a team of faculty or group.
4. An instance of or occurrence and development of discoveries or findings.

NFS is the network file system, which is used to mount or link the file system or simply folders from one linux machine to another linux machine.
This mounting makes folders and files transparently available  to the other linux machines across the network.

NFS service

NFS service is the linux service application which runs nfs server on the background, so that nfs clients can access.

How to start the NFS file system

service nfs start

or

service nfs restart

or

/etc/init.d/nfs start

or

/etc/init.d/nfs restart

But before starting nfs service you should make sure that portmap service is running, this is because nfs service depends on portmap service

How to start portmap service

service portmap start

or

service portmap restart

or

/etc/init.d/portmap start

or

/etc/init.d/portmap restart

Mounting means just copying the files from source Linux machine to the target Linux machine, to be exact it is  not exactly copy, but it is a link  to the file(s) from the source computer through LAN network and you would see all the files as those were local files.

To have this NFS file system in your computer, you should have NFS service daemon and portmap service daemon installed, and most probably these service comes with your linux operating system.

To check if the NFS and portmap service daemons installed or not, run below commands

service portmap status

If portmap is already installed, it will shows the status otherwise shows unrecognized service.

service nfs status

If NFS is already installed, it will shows the status otherwise shows unrecognized service.

Finally, to mount file/files from one computer to another computer, run below command

mount -t nfs <target_host_ip>:/file/path /file/path

<target_host_ip>:/file/path – target is the your target linux computer and /file/path is file path that you want to mount or copy to the another machine. The path should be from root.

Second argument “/file/path” is the folder path in your target linux  box, and this should be exist, mean you should create it before doing mount.

I hope you this help in mounting files between linux machines.

Leave a comment, If you find it useful or you have any doubts or you can mail me also, find my email at contact me page.

Movable Type is premium publishing and blogging software which is developed using perl.It is used for developing blog websites, content managed websites along with  social communities. Latest version of Movable Type runs on perl 5.8.1 or above.

Unlike wordpress, another popular open source blogging software, movable type supports both static and dynaminc content publishing, but dynamic publishing requires PHP4 or PHP5. And also Movable type does not support mod_perl with Apache web server version 2.x. Movable Type is available under both open source and commercial licenses.

Internet Movie Database (IMDb.com)

Full form of IMDb is “Internet Movie Database”. IMDb.com websites is a huge collection of movies, tv and video shows. Till date it has collected over 15 million movie/tv shows information. This site has a more than 57 million monthly visitors with 17 million registered users. And no wonder this great website been developed using perl, apart from perl they also uses java and python programming languages.

BugZilla

BugZilla is a software bug tracking system. This projects mainly uses mod_perl and DBD::mysql modules for development. Major software companies across the globe uses this tool to track the software defects/bugs and effectively manage their projects.

It is a open source and free solution avaible to any one at no charge. Bugzilla also provides additional  features like tracking code changes, submitting patches and effecive communication among team members.