Server connection failure during transaction. Due to underlying exception: 'java.net.ConnectException: Connection refused'. Attempted reconnect 3 time

Just would like to remind anyone who refering to both Remote Access To MySQL Database and Setup Java, Tomcat, MySQL on Ubuntu (JSP Hosting), do remember to change the datasource property which defined via JNDI.

If you are attempting to connect to the database which sit on localhost or other host, make sure the JDBC driver URL is defined exact same on both JNDI and my.cnf. So, the JNDI would able to point to the right host where the database is sit.



Else not, your web application would not able to connect to the database and you will get error similar as below:

javax.servlet.ServletException: Unable to get connection, DataSource invalid: "org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Server connection failure during transaction. Due to underlying exception: 'java.net.ConnectException: Connection refused'.Attempted reconnect 3 times. Giving up.)"

Ubuntu Share Folder Using SAMBA

Sharing folder from Ubuntu between the network is very easy. The shared folder can be access by the same platform or Windows using SAMBA services.

Share folder on GNOME @ Ubuntu 8.04.

1. Create a new folder that you want to share.


2. Right click on the folder --> Sharing Options


3. Tick on the Share this folder


4. Click at the Install service.


5. Enter the administrator password.


6. Downloading and installing...please wait.


7. Click the close.


8. Restart the Ubuntu and it should works.

Generally,SAMBA services can be installed by:
1. At the terminal, type sudo apt-get install smbfs to download and install SAMBA.
2. Set the password for the user by sudo smbpasswd -a username. (Be sure you had created the user account. To do this: System --> Administration --> Users and Groups).

Install antivirus for Ubuntu

Download and install AVG

After installed Ubuntu, I would highly recommend to proceed with patches update and install the antivirus. The chances of Ubuntu affected by virus are rare. However, if you are connected within the network, it is recommended to have one. At this moment, I am using AVG 7.5.51 antivirus to protect my file from viruses.

You can download the free AVG from here (.deb). Once downloaded, right click and select Open with “GDebi Package Installer”. Follow the instructions carefully.

Click on the Install Packages button.


Installing..please wait.


Click the close button.


Launch the program and do the update
Once the installation done, you can start AVG by going to Applications -->Accessories -->AVG for Linux Workstation. Do the update to download the latest virus definition.


If you encountered the update problem with the message below, you may need to configure the right permission.


Open the User and Groups panel.


Click on Unlock button and sign in as the power user. Click on the Manage Groups button.


Select the avg group and click on the Properties button.



Tick on the user to assign to AVG group.


Logout and do the update again. You should able to retrieve the update.


Alternative, at terminal you can type sudo avgupdate -o to download the update. The -o parameter indicate online update from the Internet.

Remote Access To MySQL Database

Configure my.cnf
1. We will need to edit the my.cnf file. I am assuming you are using GNOME, so open the terminal and type sudo gedit /etc/mysql/my.cnf

2. Change the bind-address to your server IP address (not to 127.0.0.1). Example, I found out my server IP is 192.168.30.30 by using the ifconfig command. So here are the changes,
bind-address = 192.168.30.30

3. Be sure to comment out the skip-networking.
# skip-networking

4. Save and close the file.

Create MySQL New User Account
** Assuming to create the superuser having all privileges and accessed from localhost and other host.
5. Open terminal and start the mysql program.

6. Type this:
mysql> GRANT ALL PRIVILEGES ON *.* TO 'some_user’@'localhost'
-> IDENTIFIED BY 'some_password' WITH GRANT OPTION;
mysql> GRANT ALL PRIVILEGES ON *.* TO 'some_user'@'%'
-> IDENTIFIED BY 'some_password' WITH GRANT OPTION;

7. Restart the MySQL server by open the terminal and type sudo /etc/init.d/mysql restart