Most of the time, an OutOfMemoryError won’t crash the application, but it could put the application in an unstable state. A restart would be a prudent move in this situation, since requests served ...

In that way it reflects the purpose of the old PermSize; flag. When MaxMetaspaceSize is set, the space can still run out of memory, which will cause a "java.lang.OutOfMemoryError: Metadata space".