What initial metric should be checked to identify memory leaks in Java?

Identifying memory leaks in Java typically starts with checking garbage collection metrics. These metrics provide insights into how frequently garbage collection events occur and how much memory is being reclaimed during these processes. When a memory leak is present, the garbage collector may struggle to reclaim memory from objects that are still referenced, leading to increased memory usage over time.

Monitoring garbage collection metrics helps in understanding the efficiency of memory management, as an unusually high frequency of garbage collection or an increase in the amount of memory that is not being freed can indicate potential leaks.

Although heap size metrics can also provide valuable information about memory usage, they do not directly reflect the health of memory management as effectively as garbage collection metrics. High heap sizes could occur for reasons other than leaks, such as increased application load or just the nature of the workload. Meanwhile, CPU usage and thread count metrics are more related to overall application performance and responsiveness rather than explicitly pointing out memory management issues like leaks.