Java GC Demystified: Internals, Trade-offs, and Real-World Use Cases

Java garbage collectors (GCs) are automatic memory management components responsible for reclaiming memory occupied by objects that are no longer in use. They play a crucial role in managing Java’s dynamic memory allocation, allowing developers to focus on application logic without manual memory deallocation. GCs are needed to prevent memory leaks, optimize memory usage, and ensure the overall performance and stability of Java applications.

Before the advent of GCs, manual memory management was the norm in programming languages. Developers had to explicitly allocate and deallocate memory for objects, which often led to errors like memory leaks or dangling references. Such manual memory management was error-prone and time-consuming, requiring careful tracking and release of objects.

Java introduced automatic memory management through its GC mechanism, relieving developers from manual memory deallocation. GCs periodically identify and release memory occupied by objects that are no longer reachable or in use. This process involves several stages, including marking reachable objects, identifying unreachable objects, and reclaiming their memory.

In this document, we will cover the 10 most widely used GCs:

1. Serial GC: A simple, single-threaded GC algorithm suitable for small applications or systems with low memory requirements.
2. Parallel GC: Uses multiple threads to speed up garbage collection, making…