how a java ee application is hosted on servers

0
votes

I'm a Java EE developer (never worked in an enterprise). let's say we have a java ee 7 application (using EJB JPA JSF..) and connected to MySQL Database for example. now in the development mode you just work on your computer. my question is, let's say you have bought 5 servers (Windows). and you want to deploy the application (along with the database) on these servers. how you do that, how on server number 1 having Java, glassfish (war/ear file deployed) connect with others.

I mean if server n1 wants to get some entry from the database and that entry exists in sever n3, how is that possible????

today with the "Cloud" you don't actually know how stuff works. I need to know how the "Classic" way things works.

2
javamysqljakarta-eeglassfish
Not clear what you're asking. In your example the JDBC driver on n1 would make a network connection to the DBMS on n3. Is that what you wondered, or is there more to it? - Darwin von Corax
I mean how n1 connects/know others servers in the first place. it's like two computers running, how they're connected ?? I'm sorry if I could not explain in a clair way - usertest
You configure the data server to listen on a specific address and port (the default port depends on the database). Your JDBC connection string specifies the server's address and, optionally, port number. This is covered in the JDBC Tutorial. The greasy details are handled by the two nodes' TCP stacks; an explanation would be beyond the scope of this site. - Darwin von Corax
"the data server " so in the real world, the database exists on specific servers others than the server that run the JEE application ?? - usertest
You install the app server on a specific machine, and the DBMS on a specific machine. They may be the same machine or different machines; in both cases the network layer handles the details. - Darwin von Corax

2 Answers

1
votes

You install the app server on a specific machine, and the DBMS on a specific machine. They may be the same machine or different machines; in both cases the network layer handles the details. You configure the data server to listen on a specific address and port (the default port depends on the database). Your JDBC connection string specifies the server's address and, optionally, port number. In your example the JDBC driver on n1 would simply make a network connection to the DBMS on n3.

This is covered in the JDBC Tutorial. The greasy details are handled by the two nodes' TCP stacks; an explanation would be beyond the scope of this site.

0
votes

JEE adresses most of the topics you asked about. You shouldn't call yourself a Java EE developer and at the same time ask "what is Java EE".

Also a developer always MUST "know how stuff works" to actually make it work, no matter where it's run, that was true yesterday, today and will probably be tomorrow.

I think you are either a troll or did not even try to understand / read up at all JEE (or basically any other web / network based distributed) technology.