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:

• EASA Remote Server – 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 both rsh and ssh is to use the Web Service Compute Server (WSCS) approach within the EASA Remote Server software. An important advantage of the WSCS approach is that unlike the rsh and ssh approaches, it can successfully 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 the EASA Remote Server with Compute Server, please complete the following steps:

• Log on to the compute server on which you want to install the Remote 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, the first window to appear will be the Welcome window, which provides an introduction to the installation process. To continue, click on Next.

• The next window to appear will be the 'License Agreement' window. To continue installing the Remote Server, the radio button next to 'I accept the agreement' must be selected and you must click on Next. If you do not accept the terms of the 'License Agreement', then the installation process will be terminated.

• The Select Destination Directory window appears next and you are prompted to choose the folder in which to install the Remote Server. Make your selection and then click on Next to continue.

Note: The folder that you have selected will be referred to as <SERVICE_ROOT>.

• Next appears the Select Installation Type window and you should select Custom installation as the install type. Once you have made your selection, click on Next to continue.

• On the Select Components window, unselect all the components except the Compute Server selection and click on Next.

• The Summary screen appears next, and if you are satisfied with the settings, then click on Next to install EASA.

• Finally, the 'Completing Setup window will appear'. Select whether you want to 'Start EASA Server' now (Windows systems only) and click on Finish.

The EASA software has now been successfully installed.

Once the EASA Remote Server software is installed and running on the compute server, you will use the Web Service Server Processing object under the Server Processing List branch in the Compute Server Configuration Tool to configure the Compute Server (See Server Processing List below).

An Excel Server is a service running on the EASA Remote Server that is used specifically to run Microsoft Excel processes. The configuring of an Excel Server means that authors will be able to upload and link to spreadsheets and create interactive applications running Excel remotely on the Compute Server. To create an Excel Server, the EASA Remote Server software must be installed on the intended machine.

Note: Client computers will normally connect to Excel Servers via the EASA Server. If you decide 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 Remote Server with Excel Server, please complete the following steps:

• Log on to the Compute Server on which you want to install the Excel Server as Administrator.

• Start the installation process by double-clicking 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. To continue, click on Next.

• The next window to appear will be the 'License Agreement' window. To continue installing the Remote Server, the radio button next to 'I accept the agreement' must be selected and you must click on Next. If you do not accept the terms of the 'License Agreement', then the installation process will be terminated.

• The 'Select Destination Directory' window appears next and you are prompted to choose the folder in which to install the Remote Server. Make your selection and then click on Next to continue.

Note: The folder that you have selected will be referred to as <SERVICE_ROOT>.

• Next appears the 'Select Installation Type' window and you should select 'Custom' installation as the install type. Once you have made your selection, click on Next to continue.

• On the 'Select Components' window, unselect all the components except the 'Spreadsheet Support' selection and click on Next.

• The Summary screen appears next, and if you are satisfied with the settings, then click on Next to install EASA.

• Finally, the 'Completing Setup window will appear'. Select whether you want to Start EASA Server now and click on Finish.

The EASA software has now been successfully installed.

Note: If running Excel as a service, you must modify it to run as a user other than local system.

Once the EASA Remote Server software is installed and running on the Compute Server, you will use the Excel Server Processing object under the Server Processing List branch in the Compute Server Configuration Tool to configure the Excel Server (See SERVER PROCESSING LIST ).

If for security purposes you are not allowed to use rsh within your organization, then a common replacement for rsh is 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 (usually in the /etc/ssh directory):

 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, you will 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).

Note: 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.