For an EASA Server to communicate effectively with a Compute Server, it must be able to perform the following tasks:

• Copy files and folders to and from a Compute Server
• Delete files and folders on a Compute Server
• Execute commands on a Compute Server

There are three commonly used communication approaches between an EASA Server and a Compute Server listed below in order of our recommendations:

• plain http (default)
  • Valid for all EASA Servers and Windows Compute Servers or Linux Compute Servers. Requires installation of software, which is available within EASA, on Compute Servers.

• Secure Shell (ssh)
  • Valid for all combinations of EASA Servers and Compute Servers, but may require ssh server software from a 3rd party software vendor to be installed on the Compute Server.

• Remote Shell (rsh)
  • Only practical between Linux EASA Servers and Linux or UNIX Compute Servers. Normally, rsh service is already available on Linux or UNIX computers.

A variety of circumstances exist in which software will have to be installed on compute servers so that the EASA Server can communicate with them properly. The most common scenarios and the software to be installed in each case are listed in the table below.

An alternative to either rsh or ssh is the Web Service Compute Server (WSCS). An important advantage of the WSCS approach is that it may continue to process submitted processes when the EASA Server is shutdown and will reconnect properly when the EASA Server is started up again.

To install EASA on an Compute Server,

• Log on to remote Compute Server as Administrator.
• Start the installation process by performing one of the following steps:
  • On Windows with downloaded installer,
    • Double-click on the EASA Server installation executable (.exe) file
  • On Linux with downloaded installer,
    • Run the EASA Server installation executable (.bin) file

• After the EASA Installation Wizard initializes,
  • Click Next in the Welcome window
• Read and accept the 'License Agreement'
• Select a Destination Directory in which to install the Remote Server
• Click Next to continue.
• Select Custom installation as the install type.
• Click Next
• Unselect all the components except the Compute Server selection and click on Next.
• Confirm the settings are corrected on the Summary screen
• Click Next to install EASA
• On the 'Completing Setup' window,
  • Select whether to 'Start EASA Server' now (Windows systems only)
• Click on Finish.

The EASA software has now been successfully installed.

Configure the Compute Server via the WEB SERVICE SERVER PROCESSING object under the SERVER PROCESSING LIST branch in the Compute Server Configuration Tool (See SERVER PROCESSING LIST below).

An Excel Server is a service runs Microsoft Excel processes. An Author may upload and link a spreadsheet and create an interactive application that runs Excel remotely.

Client computers will typically connect to an Excel Server via the EASA Server. To use a direct connection, the Excel Server must be available on the network and not part of a protected sub-network.

To install the EASA on a remote Excel Server:

• Log on to the target Excel Server as Administrator.
• Double-click on the EASA Server installation executable (.exe) file.

After the EASA Installation Wizard initializes, the first window to appear will be the Welcome window, which provides an introduction to the installation process.

• Click Next.
• Read and accept the 'License Agreement'
• Select a 'Destination Directory for the Excel Server
• Click Next to continue.
• Select 'Custom' installation as the install type.
• Click Next to continue.
• On the 'Select Components' window,
  • Unselect all the components except the 'Spreadsheet Support' selection
  • Click Next.
• The Summary screen appears next,
• Click Next to install EASA.
• On the 'Completing Setup' window,
  • Select whether you want to Start EASA Server
• Click on Finish.

The EASA software has now been successfully installed.

If running Excel as a service, it must be run as a different user than local system.

Once the Excel Server software is installed and running, configure it in the EXCEL SERVER PROCESSING object under the SERVER PROCESSING LIST branch in the Compute Server Configuration Tool (See SERVER PROCESSING LIST ).

If for security purposes rsh if forbidden, use the Secure Shell (ssh) software. To use ssh instead of rsh, you will often need to install third party ssh server software on the Compute Server, especially for Windows computers. A variety of ssh tools are commercially available and a few examples are provided below:

• OpenSSH (http://www.openssh.com/)
• SSH Tectia (http://www.ssh.com)
• PuTTY (http://www.chiark.greenend.org.uk/~sgtatham/putty)

The ssh server software will typically be installed and configured to allow authentication through a user name and password. On Linux and UNIX computers, this is accomplished by having the following line in the sshd_config file (often found in /etc/ssh):

• PasswordAuthentication yes

This line of text will likely already be present, but may be commented out or be set to no. Once the ssh server is installed and running on the Compute Server, use the SSH SERVER PROCESSING object under the SERVER PROCESSING LIST branch in the Compute Server Configuration Tool to configure the Compute Server (See SERVER PROCESSING LIST).

The SSH SERVER PROCESSING can use a known_hosts file to check that the remote host is valid. Also public/private key authentication can be used as an alternative to password-based authentication.