Understanding the concurrent mode in JVM is essential when looking to understand the failures that may occur. Concurrency is explained as a process in which Java attempts to carry out multiple functions at the same time. The issue with the concurrent mode is that it can fail if the program is not able to resource enough heap to carry out simultaneous functions. The failure of the concurrent mode results in the use of stop the world garbage collection, which takes a lot of time and truly eliminates the benefits of using a low pause collector, such as the G1GC. Understanding the failure is simple; understanding the mistakes that are causing concurrent mode failures is a lot more difficult.
The Java documentation says ...
