Hands-On Software Architecture with Golang

Consensus based on time – causality

In this model, there is no explicit blocking. Whenever a process (Px) receives a value from another process (P1), and if that value was arrived at a later point in time, then Px overwrites its own copy of the value with what P1 said it was.

Generally, it is not easy to have a common clock source for all processes. The alternatives usually used are vector clocks (designed by Leslie Lamport). Essentially, a vector clock is a vector or an array of counters, one for each Process. Every time a Process sends or receives a message, this counter is incremented. When a Process shares information (the value), it also shares the vector clock it has. The receiving Process updates each element in its own vector by ...