2.3. Configuring the DataHub Web Server

DataHub APIs for C++, Java, and .NET : Version 6.4
	Chapter 2. Web Programming with Java

To configure the DataHub's web server, follow these steps:

With the DataHub running, right click on the DataHub system-tray icon and choose Properties.
In the Properties window, select Web Server .
Check the Act as web server box.

The DataHub web server is preconfigured to run on port number 80, but you might need to change that setting in the Base Configuration section:

Windows allows multiple users on a single TCP port, and never refuses a connection. However, this can cause irregular behavior. It is essential that the DataHub web server be the exclusive user of a port.

To get a list of which ports are in use on your machine, follow these steps:

From the Windows Start menu, choose Run.
Enter the executable name cmd.exe and click OK.
At the command prompt, type:
```
netstat -p tcp -b -a -n
```
The result is a table showing the tcp protocol and executable name of all programs in use. There are two columns of interest: Local Address and State. In Local Address, the numbers at the end (after the colon) are the port number that the process is using. The State column shows the state of that process. The only state we are interested in is LISTENING. Whatever port you are using for the DataHub web server, it should be the only process on that port.

If you have one or more programs established or listening on the same port as the Cascade DataHub, you have two choices:

Change the port number for the DataHub web server (as illustrated above), or

Change the port number for every other program that is using that port.

Port numbers 1 through 1024 are reserved. Port 80, for example, is reserved for HTTP, which is why we make it the default for the DataHub web server. If you change the DataHub web server from port 80, we suggest setting it to a number between 1025 and 65535.


2.2. Working with Java Applets		2.4. Testing the DataHub Web Server