As a practical use case, we will look at a database application to show the use of Singletons. Consider an example of a cloud service that involves multiple read and write operations on the database. The complete cloud service is split across multiple services that perform database operations. An action on the UI (web app) internally will call an API, which eventually results in a DB operation.
It's clear that the shared resource across different services is the database itself. So, if we need to design the cloud service better, the following points must be taken care of:
Consistency across operations in the database—one operation shouldn't result in conflicts with other operations
Memory and CPU utilization should be optimal for the handling of multiple operations on the database
A sample Python implementation is given here:
import sqlite3
class MetaSingleton(type):
_instances = {}
def __call__(cls, *args, **kwargs):
if cls...