Overview of technologies used so far

There are a number of application that work well on there own and are great for the purpose they are designed for. However everything links together some how and understanding how applications work on their own is only the start of things.

Whilst I have been learning about a number new applications, I have also been looking at how applications can work with each other to give an end to end feel of how certain Internet businesses or back end technologies really work.

There are hundreds or some times thousands of different way in which applications can link with each other within a business or over the Internet. Whether it be using a different storage database at the back end or it be writing a front end client in a different language, I have been documenting a number of working solutions already in my blog http://vidorsolutions.com

Some of the technologies I have learnt and experimented successfully with are as follows:

1. Grails application deployed into Glassfish application server, using PostgreSQL as a database. Then using tools such as PGAdmin to connect to my databases locally on my machine.

2. Ejabberd Instant Messaging server installed on a server instance in the cloud, configured to use postgreSQL as a data source. Then using PSI Desktop chat client to connect with Ejabberd account. Tools such as PGAdmin can also be used here to view the back end database, tables and structure.

To further extend this learning experience I then created a basic Android XMPP client application that could also connect to the Ejabberd Server instance.

A lot of different technologies going on here and a lot to learn about the applications alone if you've never used any of these. However once you see how all these work together you get a greater appreciation of how the end to end user experience works.

Remember for some instructions on how to use these check out my previous posts
http://vidorsolutions.com

Using PSI chat client to access Ejabberd Chat messaging server

PSI is one of many jabber/XMPP clients available across the net. You can use these type of clients to test connectivity to or use functions available on most instant messaging server instances; in this case ejabberd.

1. Firstly ensure ejabberd is running on the server and there is a user account you can log in with.

use ./ejabberdctl [start/stop/status] to view status or start instance

use ./ejabberdctl register username password to register a new user


2. Install PSI from source or package

Cross platform support available from http://psi-im.org/download/

3. Launch PSI, add a new account, ensuring you fill in the following fields:

jabber id - this is the account you create on the ejabberd server.
password - corresponding password with above account

under connection settings:
specify server IP address or host name, ensuring you complete the port number; usually 5222

4. Save all settings and view the account in PSI application.
Change status to online.

5. Test chat to another user using same method of setup above, or log into web admin page of ejabberd server at http://SERVERIP:5280/admin to confirm successfully connectivity.