Mutual exclusion in distributed system
Mutual exclusion is a concurrency control property which is introduced to prevent race conditions. It is the requirement that a process can not enter its critical section while another concurrent process…
Shipboard Level Sensors – Types and Theory
Measuring the contents of a tank is a job which most mariners hate to do. For this reason, many gauges and devices have been produced for reducing the man hours…
Distributed Mutual Exclusion
Process coordination in a multitasking OS – Race condition: several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which the…
Firefighting Equipment in Ship’s Engine Room
Ships engine rooms are susceptible to fires and explosions, as well as the engines themselves. However, there is firefighting equipment in a ships engine room to combat these hazards, such…
Logical time and logical clocks
Instead of synchronizing clocks, event ordering can be used If two events occurred at the same process pi (i = 1, 2, … N) then theyoccurred in the order observed by pi, that is order…
Causal ordering
Causal ordering is a vital tool for thinking about distributed systems. Once you understand it, many other concepts become much simpler. We'll start with the fundamental property of distributed systems:…
Marine Diesel Engines – Assembly, Components Of, and Watchkeeping For
The invention of the diesel engine in 1893 has been attributed to Rudolf Diesel, a German mechanical engineer and inventor. This was an innovative internal combustion engine that was the…
Group communication
A multicast operation is more appropriate – this is an operation that sends a single message from one process to each of the members of a group of processes, usually in such a…
Global Name Service (GNS)
Designed and implemented by Lampson and colleagues at the DEC Systems Research Center (1986) Provide facilities for resource location, email addressing and authentication When the naming database grows from small…
Synchronizing physical clocks
Two models of synchronization 1) External synchronization 2) Internal synchronization External synchronization: a computer‘s clock Ci is synchronized with an external authoritative time source S, so that: |S(t) - Ci(t)| < D for i = 1, 2, …N over an interval, I of…
