When adding a new Compute Server, there are two main questions to answer first before determining the rest of the configuration settings. The questions are:

1. What approach, rsh, ssh, WSCS or Excel Server, will be used to handle communications between the EASA Server and the Compute Server?
2. Which software applications will EASA run on this Compute Server?

The first choice determines which object is set in the Server Processing: parameter of a COMPUTE SERVER object.

The second answer will defined additions to SOFTWARE LIST, ENVIRONMENT LIST and LICENSING branches of the Tree. These objects will then be referred to in the Software: and Environment: parameters of a COMPUTE SERVER object.

When configuring a Compute Server running Windows, you have two communication approaches to choose from:

• Web Service Server Processing - requires EASA Remote Server software with Compute Server service to be installed and running on compute server. For details on installing EASA Remote Server, see Installing Remote Server Software on Compute Server page.

• ssh server processing - requires ssh server to be installed and running on compute server. For details on installing an ssh service, see Using Secure Shell (ssh) Software.

When configuring a computer to be an Excel Server, there are three requirements for the computer:

• The computer’s operating system must be Windows.
• Microsoft Excel must be installed on the computer.
• The EASA Remote Server software with Excel Server service must be installed and running on the computer. For details on installing EASA Remote Server, see Installing Remote Server Software on Excel Server.

The EXCEL SERVER PROCESSING object, which is specifically designed for configuring Excel Servers, is the only approach available for establishing the communication between the EASA Server and Excel Server. For an example of configuring an Excel Server, please see Configuring Compute Servers.

Tip: When configuring an Excel Server, you can usually use the existing default EXCEL SERVER PROCESSING object under DEFAULT SERVER PROCESSING. Exceptions include use of a 'Port Number' within the Remote Server software other than 80 or a change in the 'Username' and 'Password' for authenticating communications with Remote Servers.

Note: Excel Add-ins are disabled by default in the Excel processes used by EASA. This is due to avoid unnecessary performance impacts as in most cases, full functionality is available without Add-ins.

If Excel Add-ins need to be enabled, it can be done by modifying the context.properties file found under <EASA Server Data Folder>\excel\admin\config\ by adding the following line:

   easa.excel.server.use.pi.addins.reregister=true

Excel 2016 requires an interactive user to close a popup that appears at the first innvocation, and by default an Excel Server runs as SYSTEM. We need a new second user, EASA-user that can actually log in and close this initial popup and then we run the Excel Server as that user. Follow the steps below if you are using Excel 2016.

1. Install Excel Server as you usually do
2. Stop service
3. Create new user in windows, called EASA-user
4. Login in as EASAS-user
5. Open Excel manually, close the pop up which appears when excel is opened for first time for that user
6. Logout from windows and log in with the first user that was created when windows was installed
7. Go to services, right click on EASA service and click properties
8. Go to Log On Tab, Select Log on as: This account, and enter credentials for EASA-user user
9. Start service

When configuring UNIX or Linux compute servers, you have three communication approaches to choose from:

1. Web Service Server Processing (Linux Only) - requires EASA Remote Server software with Compute Server service to be installed and running. For details on installing EASA Remote Server, see Installing Remote Server Software on Compute Server.
2. SSH Server Processing - requires ssh server to be installed and running on compute server. For details on installing an ssh service, see Using Secure Shell (ssh) Software.
3. Standard Server Processing - by default uses Remote Shell (rsh) to handle communications, so rsh needs to be installed and running.

If the third choice is selected, you can select from existing SERVER PROCESSING objects under DEFAULT SERVER PROCESSING. The table below provides guidance on the selection of the existing SERVER PROCESSING objects.

Also, with the third choice above and the use of rsh, there are a few important issues to be aware of:

• An .rhosts file containing the hostname or IP address of the EASA Server and the Username used to run it must be present on the Compute Server in the home directory of the User ID on the UNIX computer (See # 2 below).

Note: The settings for the owner, group and file permissions on the .rhosts file are also important. Set the owner to the User ID being used and the group to same group that the User ID belongs to. Finally, use file permissions of 600 or rw- --- ---.

1. A valid User ID on the Compute Server must be specified in the COMPUTE SERVER object for the server processing to function properly.
2. Using a directory on a mounted network hard drive for the Working Directory Path: parameter for multiple UNIX or Linux compute servers will reduce the number of Server processing objects required in the compute server configuration.

With Linux computers, one issue for concern is that rsh may not be activated and available for use by default in Linux. You can check whether rsh has been turned on by typing the following command in a shell window:

 chkconfig --list

You should then see a list of available services and their status. Look for the line corresponding to rsh. You will need to turn rsh on if you see the following in a shell window:

 rsh: off

You can turn rsh on by logging on the Linux computer as root and then typing the following command:

 chkconfig rsh on

To aid you in configuring your Compute Servers, a flow diagram of the configuration process is provided: