Question: We would like to put together a Thin Client system that will have a total of seven Thin Clients. While some of these clients will be standard Thin Client hardware, we would also like to use some of our PCs as clients as well. We also need to allow for some spare capacity for the future.
Can you please specify the hardware and software (ACP and Microsoft) requirements for a reliable system?
Answer: There are multiple ways to build this system. I will start by specifying the basic system (the minimum required) and then work up to a system with redundancy that will guarantee uninterrupted operation in almost every case. Each system will have the following four parts – the Thin Clients, the hosting Windows Terminal Server, the Microsoft software and the ACP software.
But first I would like to define two terms – Failover and Redundancy – the way that we use them when we talk about Thin Clients.
Failover – This describes the ability of the Thin Client to detect a problem with the Terminal Server that is hosting its session and switch to a backup Server. This obviously requires more than one Terminal Server.
Redundancy – This is the term we use to describe backup ThinManager licenses. Each time a Thin Client boots it checks for a valid ThinManager license. Once it gets this license it connects to a Terminal Server and starts a session. If the PC that holds its ThinManager license is unavailable it will not be able to boot. The way around this is to have two machines that hold the ThinManager licenses. This greatly reduces the chances that the Thin Client will not find a valid license when it boots. NOTE: Many customers load the ThinManager licenses directly on the Terminal Server(s). This is fine for smaller systems, and insures that the Thin Client can always find a valid license when it is running. This technique becomes burdensome when you have 5, 6 or more Terminal Servers and 30 or more Thin Clients.
Both Failover and Redundancy are provided by ACP to ensure the reliability of the Thin Client (or centralized computing) model. The simpler systems presented here will not have either Failover or Redundancy.
System 1 – Basic
One Microsoft Terminal Server
– PC with Windows 2003 Server OS. The least expensive OS version comes with 5 Client Access Licenses (or CALs) to allow up to 5 users simultaneously on the server, but it can be purchased with 10 CALs as well. You can add CALs as few as 5 at a time. The CALs are pretty inexpensive.
– 10 Terminal Server CALs (TS-CALs). These allow the connections of the Thin Clients (standard or fat clients) and are purchased separately from the OS. You will need a 10 client pack to cover the seven clients. This also comes in 5-client packs. NOTE: Since the release of Windows 2003 Server, TS-CALs come in two types – device and user. The distinction between these is a topic for a later newsletter.
ThinManager Software
– To support seven clients you will need a 10-pack of ThinManager, just like the Microsoft licenses. You mentioned using PCs for some of the clients. We call this a “fat client” and support it with our WinTMC product. ACP sells a special ThinManager license that allows the connection of either traditional Thin Client hardware or PCs running as a Thin Client. The ACP part number for this product is TW-30-010.
Thin Client hardware
– Either dedicated ThinManager Ready Thin Clients or fat clients. The ThinManager software package includes the Windows (WinTMC) client software as well. You can find some of the available ThinManager Ready Thin Clients on this website:
System 2 – Basic Plus Failover
Two Microsoft Terminal Servers (each with OS and CALS as above).
– The two Terminal Servers add the ability for the clients to fail over to a backup server if the primary becomes unavailable. While you could run all the clients on one of the servers and treat it as a ‘primary’, a better strategy would be to split up the system and run four clients on one server and three on the other and have them cross-fail.
ThinManager Software
– Same as the Basic system with one TW-30-010.
Thin Client hardware
– Same as the Basic system
System 3 – Basic Plus Failover with Redundancy
Two Microsoft Terminal Servers (each with OS and CALS as above).
ThinManager Software
– Add duplicate ThinManager licenses on each of the Terminal Servers. This means you will need two of the TW-30-010.
Thin Client hardware
– As before
System 4 – Basic Plus Instant Failover with Redundancy
Two Microsoft Terminal Servers (each with OS and CALS as above).
ThinManager Software
– Duplicate ThinManager licenses as above, with two of the TW-30-010.
ACP Instant Failover Software
– This product allows each Thin Client to start a session on the primary and the backup server at the same time. If a problem with one server is detected the client simply switches instantly to the backup session. Without Instant Failover the client has to log into the backup server and start the application. This can take up to thirty seconds or more, depending on the server load. The part number for our Instant Failover software to handle seven clients is FM-30-010. Two of each of these are needed to maintain the redundancy.
Thin Client hardware
– As before
Any of these systems will support the 7 Thin Clients you are starting with, and both provide for the system to expand to 10 clients without the need to purchase additional software or licenses.