Making your labtop battery last longer in Linux

So I went to Devoxx in Belgium, and I took my labtop along. Of course, it's in a Cinema, so there's no electrical sockets in the rooms.

I was looking to prolong the use of my labtop, so I was looking for extend the battery life.

There were several good articles about it (see below in the references.)

I choose to install the Xfce Desktop Environment, and I was pleasantly surprised my labtop managed to hold together for a lot longer.

Fedora has some notes on how to install it, it's basically running the package manager properly, and it's done.

It can be selected from the dropdown menu on the login screen.

I shall put the command line down here, so I do not forget:

sudo dnf install tlp tlp-rdw
sudo systemctl enable tlp

References

FOSS Post - 7 Tips to Reduce Battery Usage on Linux

https://fosspost.org/tutorials/7-tips-to-reduce-battery-usage-on-linux

Xfce Desktop Environment

https://www.xfce.org/

LXDE Desktop Environment for All

https://lxde.org/

Openbox - minimalistic window manager

http://openbox.org/wiki/Main_Page

Xfce In Fedora

https://fedoraproject.org/wiki/Xfce

Adding MariaDB JDBC Connector to Wildfly 14

1. install the database driver as a module
1. create directory WILDFLY_HOME/modules/com/mariadb/main
   $ mkdir -p modules/com/mariadb/main
2. copy database driver into that one
   $ cp ~/Downloads/mariadb-java-client-2.3.0.jar .
3. Create the file module.xml in the same folder with the following content:
   <module xmlns="urn:jboss:module:1.3" name="com.mariadb">
       <resources>
           <resource-root path="mariadb-java-client-2.3.0.jar"/>
       </resources>
       <dependencies>
           <module name="javax.api"/>
           <module name="javax.transaction.api"/>
       </dependencies>
   </module>
2. start Wildfly
   $ cd $WILDFLY_HOME/bin
   $ ./standalone.sh
3. connect to http://localhost:9990/error/index.html
4. run ./add-user.sh
   [mrbear@localhost bin]$ ./add-user.sh 
   
   What type of user do you wish to add? 
    a) Management User (mgmt-users.properties) 
    b) Application User (application-users.properties)
   (a): a
   
   Enter the details of the new user to add.
   Using realm 'ManagementRealm' as discovered from the existing property files.
   Username : mrbear
   Password recommendations are listed below. To modify these restrictions edit the add-user.properties configuration file.
    - The password should be different from the username
    - The password should not be one of the following restricted values {root, admin, administrator}
    - The password should contain at least 8 characters, 1 alphabetic character(s), 1 digit(s), 1 non-alphanumeric symbol(s)
   Password : 
   Re-enter Password :  
   What groups do you want this user to belong to? (Please enter a comma separated list, or leave blank for none)[  ]: 
   About to add user 'mrbear' for realm 'ManagementRealm'
   Is this correct yes/no? yes
   Added user 'mrbear' to file '/home/mrbear/wildfly-14.0.1.Final/standalone/configuration/mgmt-users.properties'
   Added user 'mrbear' to file '/home/mrbear/wildfly-14.0.1.Final/domain/configuration/mgmt-users.properties'
   Added user 'mrbear' with groups  to file '/home/mrbear/wildfly-14.0.1.Final/standalone/configuration/mgmt-groups.properties'
   Added user 'mrbear' with groups  to file '/home/mrbear/wildfly-14.0.1.Final/domain/configuration/mgmt-groups.properties'
   Is this new user going to be used for one AS process to connect to another AS process? 
   e.g. for a slave host controller connecting to the master or for a Remoting connection for server to server EJB calls.
   yes/no? no
5. click on "Try again" on the Website
6. log on with the new added user
7. Configuration - Subsystems - Datasources and drivers - JDBC drivers - [+]
8. Fill out the following information:

   Driver name	mariadb
   Driver Module Name	com.mariadb
   Module Slot
   Driver Class Name	org.mariadb.jdbc.Driver
   Drive Datasource Class Name
   Driver XA Datasource Class Name

9. Configuration - Subsystems - Datasources and drivers - Datasources - [+]
10. Select "Add Datasource" to add a non-XA Datasource
11. Select "Custom" template
12. Attributes:

    Name	[name]
    JNDI Name	java:/jdbc/[name]

13. JDBC Driver

    Driver Name	mariadb
    Driver Module Name	[empty]
    Driver Class Name	[empty]

14. Connection:

    Connection URL	jdbc:mariadb://localhost:3306/[databasename]
    User name	root
    Password	itsasecret
    Security Domain	[empty]

15. Test connection
16. Reload of server required - so reload the server
17. Test connection: Successfully tested connection for datasource [name].

References

JDBC Driver / DataSource Setup

https://hal.gitbooks.io/dev/content/recipes/jdbc-driver-setup.html

About MariaDB Connector/J

https://mariadb.com/kb/en/library/about-mariadb-connector-j/

GitHub - Use MariaDB Connector/J Driver

https://github.com/MariaDB/mariadb-connector-j/blob/master/documentation/use-mariadb-connector-j-driver.creole

IronJacamar 1.1 - Userguide - Deploying DS Descriptor

http://www.ironjacamar.org/doc/userguide/1.1/en-US/html_single/index.html#deployingds_descriptor