System and method for two-tier adaptive heap management in a virtual machine environment

摘要

In accordance with an embodiment, described herein is a system and method for two-tier adaptive heap management (AHM) in a virtual machine environment, such as a Java virtual machine (JVM). In accordance with an embodiment, a two-tier AHM approach recognizes that more virtual machines can be run on a particular host, or the same number of virtual machines can support higher load while minimizing out-of-memory occurrences, swapping, and long old garbage collection pauses, if the heap is divided into tiers, so that a garbage collection policy that minimizes pause time can be used in a first (normal) tier, and a garbage collection policy that favors heap compaction and release of free memory to the host can be used in another (high-heap) tier.

主权项

1. A system for two-tier adaptive heap management in a virtual machine, comprising:
a computer including a hardware processor and a memory; and an adaptive heap management component, which executes at the computer, and interacts with a virtual machine operating on the computer and associated with a heap, so that a garbage collection policy that minimizes pause time is used with a first tier representative of a first level of usage of the heap, and a garbage collection policy that favors compaction and release of free memory is used with a second tier representative of a higher level of usage of the heap; wherein the adaptive heap management component
determines a soft limit on maximum heap size which is
greater than a minimum heap size value as defined by a startup parameter, andless than a maximum heap size value as defined by a startup parameter,determines the second tier representative of the higher level of usage of the heap to be a level of heap usage that is between the soft limit on maximum heap size and the maximum heap size value, andevaluates, while the level of heap usage is within the second tier representative of the higher level of usage of the heap, an amount of memory that would be freed by compaction, and, based on the amount of memory that would be freed, determines whether to compact the heap.