singleton - Use cases of the Signleton pattern -
i doing test, , confused on below question. which type of application benefit using singleton pattern? a. application interacts external systems in serial fashion. b. application interacts external systems in parallel fashion. c. clustered application can support 200 concurrent users. d. application requires remote monitoring capabilities there tests right answer , other tests answer d. correct answer? what (e) - small project not going heavily tested? singleton anti-pattern. should not use in system pollutes global state, more complex , less useful. don't want coupled singleton. moreover, using in multi-threaded environment lead disaster. imagine have several tests each changes singleton's instance. imagine tests concurring. eliminate use of singleton pattern in code-base , start considering better design. suggest taking advantage of dependency inversion principle , using dependency container instead.