Database connection pool: Single instance mode is used to ensure only one instance of the database connection pool, avoiding the cost of frequent creation and destruction of connection pools.
Logging System: Utilizing the singleton pattern to ensure only one logging instance, effectively managing log records and preventing confusion between multiple logging instances.
Thread Pool: Utilizing the singleton design pattern to ensure there is only one instance of the thread pool, allowing for centralized management of thread resources and preventing wastage of said resources.
Configuration Manager: Implementing the singleton pattern to ensure there is only one instance of the configuration manager, which helps centralize the management of system configuration information for easier configuration management.
Global cache: Employing the singleton pattern to ensure there is only one instance of the global cache, to streamline the management of cached data throughout the system, enhancing performance and maintainability.
