The lecture will be architecture and characteristics of distributed systems[1][21]. A distributed control system is a collection of independent machines or automatic interconnected into a single, coherent, logical whole. Most of these devices are computers connected through a local area network(LAN)[2], or wide area network(WAN)[3] or metropolitan(MAN)[25]. The basic advantages of distributed systems include resource sharing[4] and transparency[5]. Transparency is characterized mainly by the fact that it gives a single user group, and their illusion of a centralized, compact, consistent operating system resistant to various types of failures.
We can distinguish the following types of transparency in a distributed system:

1. Location transparency[6]
2. Migration transparency[7]
3. Relocation transparency[8]
4. Replication transparency[9]
5. Concurrent transparency[8]
6. Failure transparency[10]
7. Persistence transparency[11]
8. Security transparency[12]

The basic features of a distributed system include:

1. resource sharing[4], including files, printers and other peripherals
2. openness to the extension or expansion of different manufacturers in terms of system hardware and software
3. concurrency[13] or perform many processes and tasks simultaneously
4. scalability[14] is the ability to expand with new computers or technical equipment
5. fault tolerance[15], namely, a coherent system despite the failure of individual computers in the cluster[23] or the grid[24]
6. transparency is the perception of the system as a whole by the user (hiding the heterogeneity[26] of users, operating systems, differences in communication and organization)

One of the main advantages and differences that occur in distributed systems is the presence of an middleware[16], which mediates the communication between applications.

Examples of middleware are:

1. Socket[17]
2. RPC (Remote Procedure Call)
3. DCE (Distributed Computing Environment)[18]
4. CORBA (Common Object Request Broker Architecture)
5. DCOM (Distributed Component Object Model)[19]
6. RMI (Remote Method Invocation)[20]

Practical exercises:

1. Install openMosix on two computers. You can either use a permanent installation on the hard disk or from a LiveCD distribution. The combination of follow through hub or switch.
2. Share a printer or folder in Windows to another computer on the network.