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For an EASA Server to communicate effectively with a Compute Server, it must be able to perform the following tasks:
There are three commonly used communication approaches between an EASA Server and a Compute Server listed below in order of our recommendations:
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.
Scenario | Software |
---|---|
The Compute Server runs under Windows or Linux and will NOT be an Excel Server. | EASA Remote Server with Compute Server service |
The Compute Server runs under Windows and it will be an Excel Server. | EASA Remote Server with Excel Server service |
Any Compute Server that requires secure encrypted communications and will NOT be an Excel Server. | Secure Shell (ssh) service |
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:
Note: The folder that you have selected will be referred to as <SERVICE_ROOT>
.
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:
Note: The folder that you have selected will be referred to as <SERVICE_ROOT>
.
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:
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.