Eviction is configured for a region and implemented on a per member basis. The Least Recently Used data on the member is chosen for eviction from the region. While eviction can be based on the number of entries in a region or on the total number of bytes used for the region, this situation concentrates on eviction based on the percentage of tenured heap space used.

LRU eviction is meant to effectively deal with occasional, bursty use of heap space. When the eviction-heap-percentage is exceeded, the resource manager evicts entries, such that they can be garbage collected and thus, free heap space. If heap memory usage exceeds the eviction-heap-percentage most of the time, then the resource manager and the garbage collector impact system performance. It means that the jvm/member is improperly sized.

If the eviction-heap-percentage is exceeded, immediate and urgent action is not needed. Instead, monitor to determine if and when further changes are indicated.

Symptoms May Include

Action to Take

Track heap space usage over time. If usage is consistently above the heap-eviction-percentage, such that evictions occur, implement one or more of the following: