什么是[完整GC（分配失败）

Question

I am seeing Allocation failure in Full GC logging message.

What is Allocation Failure when Full GC?

Is it safe to ignore?

Answer 1

Allocation failure means that there was no enough contiguous memory available in the heap to allocate. GC runs as a result of allocation failure. If there is enough space available after GC has completed then all is good. Allocation failure is different from GC failure. GC failure happens when even after GC has completed there is not enough space available to assign to process.

Answer 2

Probably, you need to set arguments before starting application ie heap size. Though running GC is not mandatory, but while testing, if you run GC from application, it can give you pointer( Maybe you need to go to boundary scenario stop the world).

Answer 3

在GC时间期间，当没有足够的空间存储从eden / survivor区域复制的多个对象时，我们需要从tenured generation分配空间。全GC意味着停止世界发生